Distribution and origin of peptide-containing nerve fibres in the rat and human mammary gland

The structures in the mammary gland involved in milk ejection have been investigated with regard to their relation to different types of peptidergic nerve fibres and their origin. Lactating rats were studied with immunohistochemistry focusing on the nipple, the parenchyma, the mammary blood vessels and the mammary nerve. The human mammary gland was also analysed. In the mammary gland from rat and human, nerve endings in the subepidermis, around smooth muscle cells in the nipple, in the connective tissue surrounding lactiferous ducts and alveoli in the nipple and in the parenchyma of the mammary gland showed immunoreactivity for calcitonin gene-related peptide, substance P, vasoactive intestinal polypeptide, peptide histidine isoleucine, neuropeptide Y, galanin and tyrosine hydroxylase, whereas dynorphin-positive nerve fibres could not be detected. The mammary nerve contained calcitonin gene-related peptide, vasoactive intestinal polypeptide, neuropeptide Y and tyrosine hydroxylase immunoreactivities; the adventitia of the mammary artery contained nerve fibres immunoreactive for neuropeptide Y and tyrosine hydroxylase, while vasoactive intestinal polypeptide-, peptide histidine isoleucine-, calcitonin gene-related peptide- and substance P-positive fibres were found in the tissue surrounding the artery. The wall of the mammary vein had nerve terminals immunoreactive for neuropeptide Y, tyrosine hydroxylase, calcitonin gene-related peptide and substance P. With the help of retrograde tracing using wheat germ agglutinin in combination with immunohistochemistry, projections of calcitonin gene-related peptide-immunoreactive cells in the dorsal root ganglia to the nipple were established. Neurons in the sympathetic stellate ganglion containing neuropeptide Y and tyrosine hydroxylase also projected to the mammary gland. Moreover retrogradely-labelled cells were found in the nodose ganglion, and they were vasoactive intestinal polypeptide-immunoreactive. These results demonstrate a rich distribution of different types of nerve fibres in structures of the mammary gland related to milk ejection. These nerve fibres and their peptides may be involved in the local control of milk ejection.     

Innervation and nitric oxide modulation of mesenteric arteries of the golden hamster

Immunohistochemical and pharmacological techniques were used to examine perivascular nerves, endothelium and the effects of inhibition of nitric oxide synthesis on responses in mesenteric arteries/perfused mesenteric arterial beds of the Golden hamster. Frequency-dependent vasoconstrictions to electrical field stimulation and dose-dependent vasoconstrictions to noradrenaline were significantly augmented by NG-nitro-L-arginine methyl ester (10(-5) M), an inhibitor of nitric oxide synthase. In preparations with tone raised with methoxamine (10 microM) dose-dependent relaxations to ATP, but not to acetylcholine, were blocked by NG-nitro-L-arginine methyl ester. In the presence of guanethidine (5 microM) to block sympathetic neurotransmission there was no neurogenic relaxation to electrical field stimulation. Furthermore, the sensory neurotoxin capsaicin (0.05-5 nmol) did not elicit relaxation. Immunohistochemical studies demonstrated dense plexuses of fibres immunoreactive for tyrosine hydroxylase and neuropeptide Y, a plexus of moderate density for calcitionin gene-related peptide and an absence of fibres immunoreactive for substance P and vasoactive intestinal polypeptide. Of particular interest is the finding that whereas sympathetic perivascular nerves and nitric oxide regulate the function of hamster mesenteric arteries, there is no apparent motor function of calcitonin gene-related peptide-containing sensory nerves.     

Colocalization of nitric oxide synthase and some neurotransmitters in the intramural ganglia of the guinea pig urinary bladder

The distribution of nitrergic neurons was investigated by using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and nitric oxide synthase (NOS) immunohistochemistry in wholemount preparations of the urinary bladder in guinea pigs. Both NADPH-d+ and NOS+ neurons were located predominantly in the bladder base. Double staining showed that 70.9% of the NADPH-d+ neurons coexpressed NOS. Acetylcholinesterase histochemistry revealed that a majority of the intramural neurons were reactive, and about half of them (51.4%) were double labelled for NOS. Tyrosine hydroxylase-positive neurons were also distributed mainly in the bladder base but in a neuronal population that was separate from the preponderant NADPH-d+ neurons. Vasoactive intestinal polypeptide immunoreactivity was also detected in the some of intramural ganglion cells, in which 21.3% of them coexpressed NADPH-d. Calcitonin gene-related peptide and substance P immunoreactivities were confined to nerve fibers, often in close association with NADPH-d+ cells or extended along the blood vessels. These results have demonstrated the colocalization of NADPH-d and NOS in the majority of intramural ganglion cells. Many of the nitrergic neurons are apparently cholinergic, indicating that they are parasympathetic postganglionic neurons, and this underscores NO as the major neuromodulator in the parasympathetic nerves in the bladder walls. The localization of vasoactive intestinal polypeptide in nitrergic neurons suggests that the peptide may complement NO for regulation of micturition reflex. The close relationship of NADPH-d-reactive intramural neurons with calcitonin gene-related peptide and substance P fibers, most probably derived from dorsal root ganglion cells, suggests that NO released from the local neurons may exert its influence on the sensory neural pathways in the urinary bladder.     

Five inhibitory transmitters coexist in pelvic autonomic vasodilator neurons

Here we describe the localization of a potent vasodilator, calcitonin gene-related peptide (CGRP), in pelvic autonomic neurons containing four other inhibitory transmitters: vasoactive intestinal peptide (VIP), neuropeptide Y, nitric oxide and acetylcholine. These neurons mediate endothelium-independent vasodilation by releasing nitric oxide and one or more neuropeptides. Sixty percent of nerve cell bodies in guinea-pig paracervical ganglia with immunoreactivity (IR) for VIP, choline acetyltransferase (ChAT) and nitric oxide synthase (NOS), also contained IR for CGRP. Furthermore, many VIP-IR varicose nerve terminals at the adventitia-medial junction of the guinea-pig uterine artery contained IR for CGRP, ChAT and NOS. Both alpha-hCGRP and beta-hCGRP were potent dilators of the uterine artery (pD2 values 8.1, 8.3, respectively), but 1 microM hCGRP(8-37) did not antagonize dilations produced by either agonist. Dilations produced by alpha-hCGRP were unaffected by removal of the endothelium. Taken together with results of our previous studies, we propose that CGRP can contribute directly to autonomic vasodilation, possibly via CGRP2 receptors on smooth muscle cells, and that CGRP is the fifth inhibitory transmitter co-existing in pelvic vasodilator neurons.     

Morphological and immunohistochemical identification of neurons and their targets in the guinea-pig duodenum

Nerve circuits within the proximal duodenum were investigated using a combination of immunohistochemistry for individual neuron markers and lesion of intrinsic nerve pathways to determine axon projections. Cell shapes and axonal projections were also studied in cells that had been injected with a marker substance. Several major neuron populations were identified. Calbindin immunoreactivity occurred in a population of myenteric nerve cells with Dogiel type II morphology. These had axons that projected to other myenteric ganglia, to the circular muscle and to the mucosa. All were immunoreactive for the synthesizing enzyme for acetylcholine, choline acetyltransferase, and some were also immunoreactive for calretinin. Myenteric neurons with nitric oxide synthase immunoreactivity projected anally to the circular muscle. These were also immunoreactive for vasoactive intestinal peptide, and proportions of them had enkephalin and/or neuropeptide Y immunoreactivity. It is suggested that they are inhibitory motor neurons to the circular muscle. A very few (about 2%) of nitric oxide synthase-immunoreactive neurons had choline acetyltransferase immunoreactivity. Tachykinin (substance P)-immunoreactive nerve cells were numerous in the myenteric plexus. Some of these projected orally to the circular muscle and are concluded to be excitatory motor neurons. Others projected to the tertiary plexus which innervates the longitudinal muscle and others provided terminals in the myenteric plexus. Two groups of descending interneurons were identified, one with somatostatin immunoreactivity and one with vasoactive intestinal peptide immunoreactivity. The two most common nerve cells in submucous ganglia were neuropeptide Y- and vasoactive intestinal peptide-immunoreactive nerve cells. Both provided innervation of the mucosa. There was also a population of calretinin-immunoreactive submucous neurons that innervated the mucosal glands, but not the villi. Comparison with the ileum reveals similarities in the chemistries and projections of neurons. Differences include the almost complete absence of nitric oxide synthase immunoreactivity from vasoactive intestinal peptide-immunoreactive interneurons in the duodenum, the projection of calbindin-immunoreactive Dogiel type II neurons to the circular muscle and the absence of tachykinin-immunoreactivity from these neurons.     

Spectral and interferometrical study of the interaction of haemin with glutathione

Neurones in the ureterovesical ganglion complex provide autonomic innervation to the pelvic ureter, the ureterovesical junction and the bladder trigone. We examined the distribution and peptide co-expression pattern of nitric oxide synthase (NOS) in the human ureterovesical ganglia by combining NADPH-diaphorase histochemistry with immunoreactivity for vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP). Less than 20% of nerve cells in the large ganglia of the ureterovesical complex were stained for NOS activity. In elderly individuals, ganglion cells regularly exhibited conspicuous morphological alterations suggestive of degenerative changes. Most of the NOS-positive cell bodies costained for VIP-immunoreactivity. A minority of NOS-expressing cells also reacted for NPY-immunoreactivity. CGRP-immunoreactivity was present in varicose terminal-like nerve fibres which were found to encircle NOS-containing perikarya. Occasionally, NOS-positive somata were surrounded by plexiform axon terminals which immunostained for VIP or NPY. We conclude that the passage of urine across the ureterovesical junction is under relaxatory control of a local nitric oxide/VIP(NPY) pathway which may be modulated by preganglionic efferent and/or primary afferent input.     

The effect of treatment variables on mood and social adjustment in adult patients with pituitary disease

The effect of 50 days of streptozotocine-induced diabetes mellitus (blood glucose 20 mmol/l) on contraction and relaxation of isolated renal and intrarenal arteries in rats were examined. Strong and similar contractions were induced by potassium (60 mM), 5-hydroxytryptamine (5-HT) and endothelin-1 (ET-1) in renal and intrarenal arteries in diabetic and control rats. The vasodilatory reactivity, after precontraction with 5-HT, of neuropeptide Y (NPY) was similar to that of acetylcholine (ACh), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) and was similar in diabetic and control rats. The relaxing effect of NPY was decreased (40%) only in the diabetic group by blockade of nitric oxide synthase with NG-nitro-L-arginine methyl ester (10(-4) M) and by blockade (50%) of NPY with alpha-trinositol (10(-6) M). In conclusion, the present study showed that diabetes mellitus in the rat is associated with normal vasoconstrictive and vasodilatory capacities. However, the vasodilatory response to NPY was largely eliminated by blockade of nitric oxide synthesis only in the diabetic animals. This indicates that the vasodilatory effect of NPY in diabetes mellitus may be dependent on nitric oxide synthesis.     

Human and clinical perspectives on leptin

The neurochemical coding of neurones located in ganglia of the nerve trunk accompanying the chicken ureter was analysed and quantified using NADPH-diaphorase reactivity and immunohistochemistry against tyrosine hydroxylase (TH), nitric oxide synthase (NOS), calbindin (CAL), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), somatostatin (SOM), substance P (SP) and calcitonin gene-related peptide (CGRP) in untreated or colchicine-treated preparation. Almost all neurones were either positive for TH (38%) or for SOM (60%). Only 4% of the neurones were both TH- and SOM-positive and 3% of the neurones exhibited neither TH nor SOM immunoreactivity. The relative numbers of NPY-, NOS-, CAL- and VIP-positive neurones were 57%, 28%, 14% and 7%, respectively. No SP- or CGRP-positive neurones were observed. All NADPH-diaphorase-positive neurones expressed NOS immunoreactivity. Only in some TH-positive neurones was NPY and/or NOS found. Four major subpopulations were found in the ureteric ganglia. The SOM-positive neurones were subdivided into SOM/NPY/NOS- (28% of all neurones), SOM/NPY- (18%) and SOM/CAL/NPY-positive neurones (14%). A subpopulation of these peptid- ergic neurones also contained VIP. About 35% of the neurones contained TH only. Neurones of all subpopulations (72% of the neurones), except most of the CAL-positive neurones, were encircled by dense plexus of varicose SP/CGRP-positive, presumably sensory nerve fibres. Dense plexus of VIP-positive fibres were observed around 89% of the neurones. The chemical coding of the neuronal subpopulations identified in the ganglia accompanying the chicken ureter resembled that observed in the ganglia of Remak's nerve but was remarkably different from that of the autonomic neurones described in mammalian species.     

Hirschsprung's disease--immunohistochemical findings

Hirschsprung's disease (HSCR) is characterized by a non-propulsive distal intestinal segment (usually colon) leading to a functional obstruction. An absence of ganglia in the affected segment explains the synonymous term "aganglionosis coli". The lack of peristalsis is partly due to a deficient intestinal smooth muscle relaxation based on an absence of non-adrenergic, non-cholinergic (NANC) inhibitory innervation. Morphological studies using conventional microscopy, immunohistochemistry and immunochemistry against general neuronal markers and neuropeptides have been used to characterize the disturbed NANC innervation in HSCR. An increased cholinergic and adrenergic innervation is registered in the aganglionic segment in spite of the lack of neuronal cell bodies: Neuropeptides like vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating polypeptide (PACAP), gastrin-releasing peptide (GRP), calcitonin gene-related peptide (CGRP), substance P (SP), enkephalins and galanin immunoreactive nerve fibres are all reduced in number in the aganglionic segment. In contrast, neuropeptide Y (NPY)-containing nerve fibres are increased in number in the diseased segment, probably reflecting the adrenergic hyperinnervation. General neuronal markers including chromogranins have been used to map the neuronal network in the HSCR intestine and also to investigate the endocrine cell system in the intestinal mucosa. Nitric oxide is a potent component of the NANC inhibitory innervation and its synthesizing enzyme, nitric oxide synthase (NOS), is shown to be almost absent in the neuronal system in aganglionic intestine.     

Sensory and autonomic innervation of the facet joint in the rat lumbar spine

The presence of sensory and autonomic nerves in the synovial membrane of the lumbar facet joint in rats was investigated by immunohistochemistry. Substance P and calcitonin gene-related peptide immunoreactivities, representing sensory nerves, were observed as varicose fibers in the synoviocyte layer. The fibers were predominantly nonvascular. The autonomic innervation was identified by the presence of neuropeptide Y- and tyrosine hydroxylase-positive fibers. Most of these fibers were found adjacent to or within blood vessel walls. Immunoreactivity to vasoactive intestinal polypeptide was seen in varicose nerve terminals in the synoviocyte layer, mostly unrelated to blood vessels. There is accumulating evidence of an involvement of both the sensory and sympathetic nervous systems in inflammatory joint disease. The neuropeptides now identified in lumbar facet joints may prove to play a significant role in the pathogenesis of low-back pain.     

Monkey central retinal artery is innervated by nitroxidergic vasodilator nerves

PURPOSE: To determine whether the monkey central retinal artery is innervated by vasodilator nerves and to analyze the mechanism underlying the neurogenic response. METHODS: Changes in isometric tension were recorded in helical strips of the arteries, which were stimulated by transmurally applied electrical pulses or nicotine. The presence of perivascular nerve fibers containing nitric oxide (NO) synthase immunoreactivity was determined histologically. RESULTS: Transmural electrical stimulation (5 Hz) and nicotine produced a relaxation of the arterial strips denuded of the endothelium, treated with prazosin, and contracted with prostaglandin F2 alpha. The response was not influenced by timolol, atropine, and indomethacin, but it was abolished by methylene blue and oxyhemoglobin. NG-nitro-L-arginine, a NO synthase inhibitor, abolished the neurogenic relaxation, and L-arginine restored the response. Antagonists of calcitonin gene-related peptide and vasoactive intestinal polypeptide in sufficient concentrations did not influence the response to nerve stimulation by nicotine. There were abundant nerve fibers and bundles containing NO synthase immunoreactivity in the adventitia. CONCLUSIONS: Monkey central retinal arteries are innervated by NO synthase-containing nerves that liberate NO possibly as a neurotransmitter on excitation to produce muscular relaxation.     

Specific detection and quantification of palmitoyl-stearoyl-phosphatidylserine in human blood using normal-phase liquid chromatography coupled with electrospray mass spectrometry

We have made an immunohistochemical study of the vomeronasal (VN) complex of 12-day-old rats to characterize the innervation of its blood vessels. The VN complex can be subdivided into rostral, middle and caudal segments, each one with a particular vascularization pattern. Several small vessels were associated with the rostral segment, whereas a large venous sinus ran along the middle and caudal segments. Immunostaining for alpha-smooth muscle actin demonstrated that the muscular sheath was asymmetric, with more cells layers in its lateral than in its medial walls. Nerves were demonstrated with antisera against protein gene product 9.5 (PGP), and against several molecules associated with specific classes of nerve fibers: the C-terminal peptide of neuropeptide Y (CPON), calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL), vasoactive intestinal peptide (VIP) and neuronal nitric oxide synthase (NOS). The latter, was also studied with NADPH-diaphorase. Vascular associated fibers exhibited NOS-, CPON-, GAL-, CGRP-, SP- and VIP-immunoreactivity. Only the vessels of the rostral segment showed VIP-immunoreactive fibers. Each wall of the venous sinus exhibited different types of nerve fibers. CPON-, GAL-, CGRP- and SP-immunoreactive fibers concentrated in the medial wall, whereas NOS-immunoreactive ones concentrated in the lateral wall. This distribution of vascular fibers, plus the presence of sensory fibers exhibiting CGRP-, SP- and GAL-immunoreactivity within the pseudostratified epithelium of the VN tube, would be relevant to understand the operation of the pumping mechanism regulating influx and efflux from the VN tube.     

Innervation of two peptidergic (substance P and calcitonin gene-related peptide) nerves in the cerebral arteries and choroid plexus of the Japanese Newt (Triturus pyrrhogaster)

The pattern of cerebrovascular substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactive (-IR) innervation was investigated in the newt. SP-IR nerves supplying the cerebral arterial tree and choroid plexus were positive for CGRP, but negative for vasoactive intestinal polypeptide or neuropeptide Y. It is suggested that cerebrovascular SP- and CGRP-IR axons are sensory in nature. The supply of SP- and CGRP-IR nerves to the major cerebral arteries is relatively poor. Nevertheless, numerous SP- and CGRP-IR axons, which are contained in the fiber bundles on the cerebral carotid artery and the basilar artery, spread widely over the microvascular-epithelial regions of the choroid plexuses. It must be considered in relation to the significant role of SP- and CGRP-IR neuronal mechanisms responsible to the microcirculation, cerebrospinal fluid (CSF) production and transport action within the choroid plexus in the nutrition of the newt brain via the CSF.     

Sequence diversity of SIV(Mne) Nef in vivo and in vitro

The immune system and nervous system are intimately related. In addition to neuroendocrine mechanisms, neuropeptides have a variety of effects on immune cells and are responsible at least in part for neurogenic inflammation. The presence of neuropeptides in the skin has been well documented. The influence of neuropeptides on Langerhans cells is the focus of this paper. The physical presence and effects of calcitonin gene-related peptide on Langerhans cells is emphasized. Discussion also includes the putative inflammatory and immunologic roles of vasoactive intestinal peptide, substance P, neurotensin, neuropeptide Y, and somatostatin in the skin.     

Genome-wide analysis of integral membrane proteins from eubacterial, archaean, and eukaryotic organisms

The aim of this study was to study innervation and angiogenesis in response to grafts of dermis and cultured keratinocytes using immunohistochemical techniques. In a porcine model, fresh autologous de-epidermalized dermis and cultured autologous keratinocytes were combined using a two-stage technique, to produce keratodermal grafts. Wounds were encased within skin graft chambers that prevented the influence of the surrounding skin. As grafts contracted, a peripheral rim of granulation tissue became exposed, allowing us to compare the wound bed beneath grafts with that beneath the raw granulating surface. Grafts were studied for 6 weeks. Angiogenesis was studied using antisera to von Willebrand factor to detect endothelial cells. Nerve growth was studied using antisera to S-100, a Schwann cell marker, and to four axonal markers: protein gene product 9.5, C-flanking peptide of neuropeptide Y, calcitonin gene-related peptide, and vasoactive intestinal peptide. In kerato-dermal grafts (n = 28), organization of blood vessels and nerve growth occurred only beneath areas with epidermal cover as compared with the surrounding granulation tissue. Initially, the immunoreactivity to von Willebrand factor was high, but in areas with epidermal cover it assumed a more orderly pattern with fewer blood vessels. Innervation was first detected by S-100 immunoreactivity seen at 1 to 2 weeks, closely followed by that to protein gene product 9.5 and much later to calcitonin gene-related peptide. C-flanking peptide of neuropeptide Y and vasoactive intestinal peptide immunoreactivity were detected in the wound depth surrounding large blood vessels at 4 to 6 weeks. In control wounds that had been either grafted with de-epidermalized dermis alone (n = 10) or allowed to granulate (n = 10), persistently there was high immunoreactivity to von Willebrand factor but minimal immunoreactivity to the neural markers. In conclusion, kerato-dermal grafts become innervated, and beneath their surface there is also vascular organization to resemble normal skin. Keratinocytes themselves may influence angiogenesis and innervation, as both processes failed to occur beneath granulating areas.     

Abnormalities of neuropeptides and neural markers in the esophagus of fetal rats with adriamycin-induced esophageal atresia

BACKGROUND/PURPOSE: To investigate the distribution of neural markers and neuropeptides in esophageal atresia (EA). METHODS: A fetal rat model with Adriamycin-induced EA was used. The animals were divided into four groups: (1) control group, (2) saline-injected group, (3) Adriamycin administered but without the development of EA, and (4) Adriamycin-induced EA group. Specimens of the distal esophagus from each group were immunostained using antibodies to S100, protein gene product 9.5 (PGP), somatostatin, vasoactive intestine peptide (VIP), bombesin, galanin, substance P, neuropeptide Y (NPY), calcitonin gene-related product (CGRP), met-encephalin, nitric oxide synthase, and tyrosine hydroxylase. RESULTS: The total cross-sectional area of the distal atretic esophagus was significantly smaller than controls (P = .01), the submucosa being the component most affected (0.0465 v 0.0234 mm). Immunoreactivity for S100 and galanin were significantly elevated in the atresia group (0.0288 v 0.0079 and .001 v 0.000). In addition, there was also an increase in CGRP and Substance P in the atretic group. CONCLUSION: The elevated levels of S100 and galanin could explain the disordered motility observed in patients who had esophageal atresia.     

Clinical presentations and results of therapy of 63 acromegalic patients Chang Gung Memorial Hospital

The role of nitric oxide in inflammatory responses to substance P and other mediators of inflammation was examined in rat skin microvasculature in a blister base raised on the hind footpad. Superfusion of substance P (1 microM) over the blister base caused an increase in plasma extravasation and a vasodilator response which was not maintained. N(G)-Nitro-L-arginine (100 microM), an inhibitor of nitric oxide biosynthesis, attenuated vasodilatation and plasma extravasation due to substance P. The inactive isomer N(G)-nitro-D-arginine was without effect. Neurokinin A (1 microM), 5-hydroxytryptamine (1 microM), ATP (50 microM) and vasoactive intestinal polypeptide (1 microM) elicited vasodilation, which for vasoactive intestinal polypeptide was maintained even after washout. 5-Hydroxytryptamine and neurokinin A, but not ATP or vasoactive intestinal polypeptide, significantly increased plasma extravasation. Vasodilatation to neurokinin A, 5-hydroxytryptamine and ATP, and the increase in plasma extravasation due to neurokinin A and 5-hydroxytryptamine were unaffected by N(G)-nitro-L-arginine (100 microM), whereas vasodilation due to vasoactive intestinal polypeptide was significantly attenuated. These findings suggest that in rat skin microvasculature in vivo, nitric oxide is involved in vasodilator responses due to substance P and vasoactive intestinal polypeptide, and plasma extravasation due to substance P, but does not contribute significantly to vasodilatation induced by neurokinin A, 5-hydroxytryptamine or ATP, or the plasma extravasation induced by neurokinin A or 5-hydroxytryptamine.     

Synergistic inhibitory effect of angiotensin-converting enzyme inhibitor and heparin on intimal hyperplasia after rat aorta injury

To study the interaction between human recombinant interleukin-1 alpha and the nervous system, substance P-, neurokinin A-, calcitonin gene-related peptide-, and neuropeptide Y-like immunoreactivity in the cerebrospinal fluid, plasma, and temporomandibular joint (TMJ) perfusates of rats during acute experimental monarthritis were examined. The right TMJs of the experimental rats were injected with 0.01 mL of human recombinant interleukin-1 alpha. The right TMJs of control rats were injected with 0.01 mL of saline. Cerebrospinal fluid, plasma, and perfusates from the right TMJs were obtained at 2, 6, and 24 hours following injection, and neuropeptide-like immunoreactivity was analyzed by specific radioimmunoassays. Values of neuropeptide-like immunoreactivity for the experimental rats were compared with those of the control rats. In the experimental group, substance P-, neurokinin A-, and calcitonin gene-related peptide-like immunoreactivities were increased in cerebrospinal fluid compared to those of the control group. In plasma, no changes in neuropeptide-like immunoreactivities rose significantly in the TMJ perfusates. Most pronounced changes in neuropeptide Y-like immunoreactivity occurred intra-articularly in the TMJ perfusates. The results indicate that the contribution of the nervous system to human recombinant interleukin-1 alpha-induced monarthritis is most pronounced in the affected joint.     

Immunocytochemical localization of the NPY/PYY Y1 receptor in enteric neurons, endothelial cells, and endocrine-like cells of the rat intestinal tract

Neuropeptide Y (NPY) and peptide YY (PYY) are structurally related peptides that are considered to mediate inhibitory actions on gastrointestinal motility, secretion, and blood flow. Several receptor subtypes for these peptides have been identified and the Y1, Y2, Y4/PP1, Y5, and Y5/PP2/Y2b receptors have been cloned. In this article we report the immunocytochemical localization of the Y1 receptor to myenteric and submucosal nerve cell bodies, endothelial cells, and scattered endocrine-like cells of rat intestinal tract. Moreover, double immunofluorescence demonstrates that subpopulations of the Y1 receptor-positive nerve cell bodies are immunopositive for NPY, vasoactive intestinal polypeptide, and nitric oxide synthase. In part, such co-localizations were made possible by use of peroxidase-mediated deposition of tyramide, which permitted use of antisera derived from the same species. Our observations suggest the existence of multiple neuronal, endothelial, and endocrine target sites for NPY and PYY and that some of the actions of these regulatory peptides can be mediated by vasoactive intestinal peptide and nitric oxide synthase.     

Nerve endings with structural characteristics of mechanoreceptors in the human scleral spur

PURPOSE: The innervation of the scleral spur region was investigated to learn whether mechano-receptors are present in this region. METHODS: Serial tangential sections and whole-mount preparations of the scleral spur region of 18 human eyes of different ages were investigated with electronmicroscopic and immunohistochemical methods. For immunohistochemistry antibodies against neurofilament-proteins, synaptophysin, substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), tyrosine-hydroxylase, dopamine-beta-hydroxylase, and acetylcholinesterase were used. RESULTS: Club- or bulb-shaped nerve endings with a diameter of 5 microns to 25 microns were identified in the scleral spur region throughout the whole circumference of the eyes. The terminals derive from myelinated axons with a diameter of approximately 3 microns and stain with antibodies against neurofilament-proteins and synaptophysin but do not stain for tyrosine-hydroxylase, dopamine-beta-hydroxylase, acetylcholinesterase, NPY, VIP, SP, or CGRP. Electronmicroscopically, the endings contain abundant neurofilaments, granular and agranular vesicles of different sizes, numerous mitochondria, and lysosome-like lamellated structures. The endings are incompletely ensheathed by Schwann cells. Those areas of the cell membrane of the endings that are not covered by Schwann cells are in intimate contact with the fibrillar connective tissue elements of the scleral spur. CONCLUSION: These structural features are highly characteristic for mechanoreceptive nerve endings in other tissues of the human body. The authors therefore hypothesize that the club-or bulb-shaped nerve endings in the human scleral spur are afferent mechanoreceptors that measure stress or strain in the connective tissue elements of the scleral spur. Such changes might be induced by ciliary muscle contraction and/or by changes in intraocular pressure.