Retinal cholinergic system: characterization of rat retinal acetyltransferases using specific inhibitors of choline- and carnitine-acetyltransferases

Choline acetyltransferase catalyzes the synthesis of acetylcholine from choline and acetylcoenzyme A (ACoA) in both nervous and non-nervous tissues. Carnitine acetyltransferase occurs in several tissues and transfers acetyl groups from ACoA to carnitine forming acetylcarnitine and exhibits weak choline acetyltransferase activity. Several haloacetylcholines and haloacetylcarnitines were synthesized to develop selective inhibitors of choline acetyltransferase and carnitine acetyltransferase. Acetylcholine is a transmitter for some presynaptic neurons and/or amacrine cells in retina. Selective inhibitors of choline acetyltransferase and carnitine acetyltransferase were used in the evaluation of choline acetyltransferase and carnitine acetyltransferase activities in the rat retina. Choline acetyltransferase and carnitine acetyltransferase activities were assayed by transferring of [14C]acetyl group from [14C]ACoA to choline or carnitine and estimating [14C]-acetylcholine or [14C]acetylcarnitine. This study gave the following results: (a) Bromoacetylcholine (BrACh) was a selective inhibitor of purified choline acetyltransferase (I50, 2.2 microM); (b) (R)-bromoacetylcarnitine [(R)-BrACa] was more potent for inhibiting purified carnitine acetyltransferase (I50, 4 microM) than purified choline acetyltransferase (I50, 46 microM); (c) Rat retinal sonicate gave choline acetyltransferase activity of 98 +/- 6 nmol of ACh formed/mg/10 min. When the carnitine acetyltransferase was completely inhibited by (R)-BrACa, the activity for choline acetyltransferase decreased to 47 +/- 1 nmol, and this decrease was possibly due to the formation of some [14C]acetylcholine by carnitine acetyltransferase. The net retinal choline acetyltransferase activity was 51 nmol acetylcholine/mg protein/10 min; (d) Rat retinal sonicate contained carnitine acetyltransferase activity of 102 +/- 7 nmol acetylcarnitine formed/mg protein/10 min. This was not altered by inhibition of choline acetyltransferase with BrACh. This means that choline acetyltransferase did not use carnitine as a substrate. Choline acetyltransferase and carnitine acetyltransferase activities did not change after dialysis of retinal sonicates at 4 degrees C for 24 hrs. These observations suggest that BrACh and (R)-BrACa are useful for assessing the correct values for choline acetyltransferase and carnitine acetyltransferase activities in retinal tissues.     

The deamination of L-arginine and the synthesis of active nitrogen compounds in Yersinia pestis

The investigations of authors concerning infants and their families were generalized on the basis of the observations of infants and their parents with some psychological problems in families. The principles of psychotherapeutic work in above-mentioned groups were formulated. Besides the methods of the diagnosis of psychical deviations development in first year infants as well as peculiarities of alterations in mother-baby system and the main forms of psychic disturbances correction in infants were also described.     

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.     

Glutamate-induced cytotoxicity in PC12 pheochromocytoma cells: role of oxidation of phospholipids, glutathione and protein sulfhydryls revealed by bcl-2 transfection

Incubation of mock-transfected PC12 rat pheochromocytoma cells (PC12) for 2 h with increasing concentrations of glutamate caused progressive loss of viability (e.g., 67% with 15 mM glutamate). In contrast, the viability of bcl-2-transfected cells (PC12/bcl-2) was unaffected by glutamate. Neither PC12 nor PC12/bcl-2 cells showed a significant incidence of apoptosis in response to glutamate. Conventional phospholipid analysis by high-performance TLC and phosphorous determination showed no significant changes in the phospholipid composition of either cell line incubated with 5 mM glutamate. The peroxyl radical initiator 2,2'-azobis(2,4-dimethylvaleronitrile) caused a pronounced loss of all major phospholipid classes in PC12 cells, but no loss of cell viability. No phospholipid peroxidation was detected in PC12/bcl-2 cells incubated with 相似文献   

The comparative effects of the NOS inhibitor, Nomega-nitro-L-arginine, and the haemoxygenase inhibitor, zinc protoporphyrin IX, on tumour blood flow

The present study was undertaken to analyse the loss of heterozygosity (LOH) of the three genes, BRCA1, BRCA2 and ATM, and their correlation to clinicopathological parameters in sporadic breast cancer. We studied 59 sets of invasive ductal carcinoma, compared to matched normal control DNA. Microsatellite markers intragenic to BRCA1 (D17S1323, D17S1322, D17S855), BRCA2 (D13S1699, D13S1701, D13S1695) and ATM (D11S2179) were simultaneously used. In addition, one marker telomeric to BRCA2 (D13S1694) and four markers flanking ATM were analysed (D11S1816, D11S1819, D11S1294, D11S1818). Thirty-one per cent of the informative cases showed loss of heterozygosity for the BRCA1 gene, 22.8% for BRCA2 gene and 40% for ATM. LOH of BRCA1 correlated with high grade tumors (p=0.0005) and negative hormone receptors (p=0.01). LOH of ATM correlated with higher grade (p=0.03) and a younger age at diagnosis (p=0.03) in our set of tumors. No correlations were detected between BRCA2 LOH and any of the analysed clinicopathological parameters. However, a correlation was detected between allelic loss of the D13S1694 marker, telomeric to BRCA2, and larger tumor sizes and negative estrogen receptors, favoring the hypothesis of the presence of another putative tumor suppressor gene, telomeric to BRCA2, in the 13q12-q14 region. Only 11 tumors had LOH at more than one of the three genes, most of them (6/11) associated LOH of BRCA1 and ATM. One tumor only combined loss of the three genes BRCA1, BRCA2 and ATM.     

Increased expression of complement component C3 in the plasma of obese Zucker fa and LA/N fa(f) rats compared with their lean counterparts

OBJECTIVES: The objectives of this study were to determine whether there are differences in the electrophoretic profiles of plasma proteins from lean and obese rats and to identify a protein that was found to be more abundant in the plasma of obese rats. RESEARCH METHODS AND PROCEDURES: Plasma proteins from lean and obese Zucker fa and LA/N fa(f) rats were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The identity of a band that was differentially expressed was determined by amino acid sequencing and Western blot analysis. RESULTS: A band migrating approximately the same distance as the 116 kDa molecular weight marker was more prominent in plasma from obese rats than in plasma of lean rats. Partial sequencing of the peptide revealed that 17 of the first 18 amino acids at the amino terminus were identical with the corresponding residues in the alpha-chain of complement component C3. Western blot analysis confirmed the identity of the peptide as complement component C3. Complement C3 activity was measured using a hemolytic assay to determine whether there was a corresponding increase in the biological activity of this component in the serum of obese rats. Serum from obese rats was found to have 1.8 times as much complement component C3 activity as serum from lean rats. DISCUSSION: Elevated levels of complement C3 in genetically obese rats may be relevant because increased amounts of C3 could serve as a reservoir from which increased amounts of acylation stimulating protein, a cleavage product of complement C3, could be produced.     

Metrological analysis of measuring systems in testing an anticipatory reaction to the position of a moving object

This study compared the effects of angiotensin converting enzyme (ACE) inhibitors captopril versus enalapril on left ventricular (LV) muscle mass and LV systolic and diastolic function in 58 patients with primary glomerulonephritis and moderate chronic renal failure. The design was a 6-8 week titration phase and 6-month maintenance phase. Mean myocardial mass calculated by M-mode echocardiography in the captopril group was 153 +/- 26 g/m2 before, and 130 +/- 14 g/m2 after 6 months of treatment, in enalapril group 147 +/- 22 g/m2 before, and 126 +/- 23 g/m2 after 6 months of treatment (p < 0.05). LV ejection fraction, early and late transmitral flow velocities and early to late LV inflow velocities ratio were not significantly affected by both ACE inhibitors.     

Antegrade colonic enemas

Thirteen children aged 6-14 (mean 8) years in whom an antegrade colonic enema procedure was performed were reviewed retrospectively. All presented with refractory constipation or faecal soiling over a 3-year period. Nine of the children had previously undergone pull-through procedures for Hirschsprung's disease or high anorectal malformations. Two were suffering from spina bifida and two from idiopathic functional constipation. The operation was performed through a right iliac fossa incision. A catheterizable conduit was created. The appendix was brought out to the wound edge and made continent by intussuscepting the appendix base into the caecum. When the appendix was absent or unusable, a caecal tube was formed. Five patients suffered minor morbidity, six required a further operative procedure and two eventually required a sigmoid colostomy. However, the eventual outcome of a continent stoma was attained in 11 of the 13 children, all of whom would have been considered for sigmoid colostomy before introduction of the antegrade colonic enema procedure.