Inhibitory effects by a submandibular gland extract on luteinizing hormone-stimulated testosterone production by testicular cells

In order to develop an animal model for in vivo testing of the displacing action of various drugs and for study of the bilirubin deposition in the brain, some molecular properties of the serum albumin from different species i.e. pig, cat, human, dog, sheep, guinea pig and rat were investigated. These albumins were found to have differences in molecular weight, Stokes radius and electrophoretic mobility. They also showed different bilirubin binding characteristics when studied by spectroscopy and fluorescence quenching. It is therefore, necessary to consider the species differences when results of animal experimentation are used as a basis for the investigation of human kernicterus.     

Metabolism of 2,4,5,2',4',5'-hexachlorobiphenyl (PCB153) in guinea pig

1. The in vitro and in vivo metabolism of 2,4,5,2',4',5'-hexachlorobiphenyl (PCB153) in guinea pig has been studied. 2. Seven metabolites were detected in the faeces of PCB153-treated animals and three were identical to those produced by dog liver microsomes. The detection of a metabolite where a chlorine atom was shifted from the 2- to 3-position strongly suggested the involvement of 2,3-arene oxide intermediate, and evidence for the concomitant formation of a 3,4-arene oxide intermediate was provided by identifying other two minor metabolites which were dechlorinated at the 4-position. 3. In vitro studies using liver microsomes from guinea pigs revealed that the 2,3-arene oxide and 3-hydroxylation pathways are the predominant metabolic routes compared with the 3,4-arene oxide pathway. Although the guinea pig is an another species that can metabolize PCB153 mainly to the 2,3-arene oxide intermediate, the rate of formation was only about one-tenth of the dog. 4. These results indicate that the ability to form this unusual 2,3-arene oxide intermediate may not be responsible for high excretion rate of this congener. Our data also suggest that the cytochrome P450-catalysed metabolism of PCB153 in the guinea pig and dog are similar, whereas for post-cytochrome P450 metabolism, the guinea pig resembles the rabbit.     

Presence of cross-reacting thymus and brain antigens in the cerebral cortex

Rabbit antisera against antigens of mouse, rabbit, guinea pig and human whole brain cross-reacted in the cytotoxic test with the lymphocytes of the thymus, lymph nodes and the spleen of these animal species. Mouse thymocytes were most sensitive to the antibrain sera (cytotoxic index -- 63--100 per cent); cells from other mouse lymphoid organs and lymphocytes of rabbit, guinea pig and man were more resistant. Bone marrow lymphocytes were not damaged by any of these sera. The antigens which induced the cytotoxic properties of the sera were found only in the human cerebral cortex, but not in the white matter of the brain stem.     

Inhibition of major histocompatibility complex class I antigen presentation in pig and primate cells by herpes simplex virus type 1 and 2 ICP47

Herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) express an immediate-early protein, ICP47, that effectively inhibits the human transporter associated with antigen presentation (TAP), blocking major histocompatibility complex (MHC) class I antigen presentation to CD8+ T cells. Previous work indicated that the mouse TAP is relatively resistant to inhibition by the HSV-1 and HSV-2 ICP47 proteins (ICP47-1 and ICP47-2) and that mouse cells infected with HSV-1 are lysed by anti-HSV CD8+ cytotoxic T lymphocytes (CTL). Therefore, mice are apparently not suitable animals in which to study the in vivo effects of ICP47. In order to find an animal model, we introduced ICP47-1 and ICP47-2 into cells from various animal species-mice, rats, guinea pigs, rabbits, dogs, pigs, cows, monkeys, and humans-and measured TAP activity in the cells. Both proteins were unable to inhibit TAP in mouse, rat, guinea pig, and rabbit cells. In contrast, ICP47-1 and ICP47-2 inhibited TAP in pig, dog, cow, and monkey cells, and the TAP in pig and dog fibroblasts was often more sensitive to both proteins than TAP in human fibroblasts. These results were extended by measuring CD8+-T-cell recognition (CTL lysis) of cells from various species. Cells were infected with recombinant HSV-1 constructed to express murine MHC class I proteins so that the cells would be recognized and lysed by well-characterized murine anti-HSV CTL unless antigen presentation was blocked by ICP47. Anti-HSV CD8+ CTL effectively lysed pig and primate cells infected with a recombinant HSV-1 ICP47- mutant but were unable to lyse pig or primate cells infected with a recombinant HSV-1 that expressed ICP47. Therefore, pigs, dogs, and monkeys may be useful animal models in which to test the effects of ICP47 on HSV pathogenesis or the use of ICP47 as a selective immunosuppressive agent.     

The effect of wound dressings on diagnostic ultrasound imaging

The 5-HT1D receptor is a potential target of anti-migraine drugs, and here its genes were cloned from chimpanzee, gorilla and rhesus monkey, via polymerase chain reactions with their genomic DNAs and the primers designed from the 5' and 3' untranslated regions of the human receptor. Direct sequencing of the polymerase chain reaction (PCR) products revealed high degrees of identity between their deduced amino acid sequences (the chimpanzee, gorilla and rhesus monkey) and that of human, differing by two, four and 11 residues, respectively. The binding properties of the receptors, as expressed in human embryonic kidney 293 cells, were compared to those obtained with the human and guinea pig receptors, the latter differing by 33 residues from the human receptor. Standard serotonergic ligands including several indoles, ergots and methiothepin bound all the cloned primate and guinea pig receptors with comparable, low nanomolar affinities, leading to high correlation coefficients among their Ki values. R(+)-8-Hydroxydipropylaminotetralin, on the other hand, bound the human receptor with the affinity higher than those for the primates and guinea pig receptors. This indicates that certain chemical templates may differentiate the molecular divergences among the 5-HT1D receptors of various animal species, and the use of the non-human primates will be beneficial for pharmacological characterizations, more relevant to the human receptor, of future novel ligands for the 5-HT1D receptor, which are potential anti-migraine drugs.     

Complications associated with rapid caffeine application to cardiac myocytes that are not voltage clamped

The rapid application of caffeine to cardiac myocytes is commonly used to assess changes in the Ca2+ content of the sarcoplasmic reticulum (SR) and to study other parameters of intracellular Ca2+ regulation. Here we examined the effects of rapid caffeine application on membrane potential, intracellular Ca2+, and cell shortening in ventricular myocytes (rat, rabbit, guinea pig, dog) and atrial myocytes (rabbit) that were not voltage clamped. Conditioning pacing was used to achieve a steady-state level of SR Ca2+ loading prior to caffeine (10 mM) application. Caffeine transiently depolarized myocytes as expected from activation of forward Na+-Ca2+ exchange. However, we also found in each species (50% rat, 36% rabbit ventricular, 53% rabbit atrial, 56% guinea pig, 31% dog) that the caffeine-induced depolarization could also trigger an action potential. Caffeine-triggered potentials were completely blocked by thapsigargin (1 microM). The Ca2+ transient and contraction that accompanied caffeine-triggered action potentials had a larger magnitude and slower rate of decline (or relaxation) than occurred during caffeine-induced subthreshold depolarizations. Thus, the use of rapid caffeine application to study SR function and [Ca2+]i regulation in myocytes that are not voltage clamped can yield erroneous results.     

Electrical parameters in gallbladders of different species. Their contribution to the origin of the transmural potential difference

Amphotericin B enhances Na+ conductance of the mucosal membrane of gallbladder epithelial cells and in such a way it modifies the brush border electromotive force. On this basis a method to measure cell and shunt resistances by comparing changes of the mucosal membrane potential (Vm) and of the transmural p.d. (Vms) is developed. This method is applied in gallbladders of different vertebrate species (i.e. rabbit, guinea pig, goose, tortoise, toad, trout). The two tested mammals, rabbit and guinea pig, exhibited a lower shunting percentage (89--93%) than the nonmammals (96--97%), but this fact did not bring about a homogeneous positive Vms. This means that shunting percent contributes, but it is not the only source of differences in Vms, in accordance with that reported by Gelarden and Rose (J. Membrane Biol. 19:37, 1974). Moreover, mammals exhibited a lower luminal resistance and a lower ratio between luminal and basolateral resistance than nonmammals. Possible causes of these differences are discussed.     

Interspecies differences in enzymes reacting with organophosphates and their inhibition by paraoxon in vitro

1 Inhibition of cholinesterases (ChE) and carboxylesterases (CaE) by paraoxon (Px) was studied in vitro in the serum, liver, lung and muscle of mouse, guinea pig, rabbit and man (serum only). Moreover, the role of Px hydrolyzing enzyme (Pxase) in the detoxification of Px was studied by inhibiting its activity with EDTA. 2 The ChE and CaE activities as well as their sensitivity to Px varied in different tissues and species. The ChEs were more sensitive than CaEs to Px except in the liver. The CaE activity in human and rabbit sera was low and resistant to Px, indicating that it may have a minor importance for the binding of Px. 3 The Px-inhibited ChEs were spontaneously reactivated in the mouse and rabbit sera during 24 h. In mouse, also the CaE activity was recovered. The presence of EDTA in the incubation medium prevented this reactivation indicating that Pxase takes part in the reactivation process. 4 In rabbit, the serum Pxase activity was very high suggesting a good Px detoxifying capacity of the rabbit serum. 5 The results show that amounts and sensitivities of esterases to OPs in rodents may markedly differ from that in man. Possible species-related differences in the affinity of ChEs and CaEs for OPs and the OP hydrolyzing activity should be taken into the consideration, when animal data are extrapolated to man.     

An investigation of the effects of maternal separation and novelty on central mechanisms mediating pituitary-adrenal activity in infant guinea pigs (Cavia porcellus).

In mammalian species in which the young exhibit a strong filial attachment (e.g., monkeys, guinea pigs), numerous studies have shown that even brief separation from the attachment figure potently elevates circulating concentrations of glucocorticoids and adrenocorticotropic hormone (ACTH). However, effects of separation on central regulation of this stress response are not known. Therefore, we investigated central mechanisms mediating pituitary-adrenal activation during maternal separation and novelty exposure in guinea pig (Cavia porcellus) pups. Corticotropin-releasing factor (CRF) mRNA expression in the hypothalamic paraventricular nucleus (PVN), and plasma cortisol and ACTH levels, were elevated only during separation in a novel environment. C-Fos activity was elevated in the medial amygdala (MeA) and reduced in the bed nucleus of the stria terminalis (BNST) during novelty exposure, regardless of separation. On the other hand, c-Fos activity was elevated in the PVN during separation, regardless of novelty exposure. These results demonstrate independent and combined effects of separation and novelty in regions of the guinea pig CNS that regulate pituitary-adrenal activity. Moreover, they suggest that a pathway from MeA to BNST to PVN mediates responses to novelty in the guinea pig pup, as in the adult rat, though inputs from other cell populations appear required to fully account for the HPA activity observed here. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cloning and characterization of the guinea pig eosinophil eotaxin receptor, C-C chemokine receptor-3: blockade using a monoclonal antibody in vivo

Certain C-C chemokines, signaling via the eotaxin receptor C-C chemokine receptor-3 (CCR3), are thought to be central mediators of eosinophil accumulation in allergic inflammation. To investigate the role of CCR3 in vivo, we cloned the guinea pig eotaxin receptor (guinea pig CCR3) from a genomic DNA library. We isolated a single-exon open reading frame coding for a 358-amino acid chemokine receptor protein with 67 and 69% homology to human and murine CCR3, respectively. When expressed in stable transfectants, this receptor bound 125I-labeled guinea pig eotaxin, 125I-labeled human monocyte chemotactic protein-3, and 125I-labeled human RANTES. In chemotaxis assays, guinea pig CCR3 transfectants responded only to guinea pig eotaxin, with a maximal effect at 100 nM. mAbs were raised that bound selectively to both guinea pig CCR3 transfectants and guinea pig eosinophils. One of these mAbs, 2A8, blocked both ligand binding to transfectants and their chemotaxis in response to eotaxin. The Ab also inhibited chemotaxis and the elevation of cytosolic calcium in guinea pig eosinophils in response to eotaxin. F(ab')2 fragments of 2A8 were prepared that retained the ability to inhibit eosinophil calcium responses to eotaxin. Pretreatment of (111)In-labeled eosinophils in vitro with F(ab')2 2A8 selectively inhibited their accumulation in response to eotaxin in vivo. These data demonstrate that functional blockade of eosinophil chemokine receptors can be achieved in vivo and provide further support for the development of novel anti-inflammatory drugs targeting eosinophil recruitment through chemokine receptor antagonism.     

Mammalian scent gland marking and social behavior.

Scent-marking behavior is a common method of olfactory communication among mammalian species. The present article reviews concepts of scent marking and presents naturalistic and laboratory illustrations of intraspecific communication. The most informative data and comparative possibilities exist for the following species: ground squirrel, Mongolian gerbil, golden hamster, guinea pig, pika, sugar glider, European rabbit, pronghorn antelope, blacktail deer, Maxwell duiker, lemur monkey, and marmoset monkey. The review points out generalities and differences among these species and suggests how the laboratory and measurement skills of behaviorists and other biologists can be used in this area of research. (41/2 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute toxicity of ethylene glycol mono-n-butyl ether in the guinea pig

Acute toxicity values, such as oral and percutaneous LD50s, are often used as the basis for classifying chemicals into toxicity categories, and their subsequent regulation. Such values obtained for ethylene glycol mono-n-butyl ether (EGBE; 2-butoxyethanol) in rats and rabbits indicate that it is moderately toxic. However, the cause of death in these acute studies appeared to be secondary to acute intravascular haemolysis, an effect for which guinea pigs and humans are much less sensitive than rats, mice and rabbits. Recently-conducted acute toxicity studies in the guinea pig resulted in an acute oral LD50 of 1400 mg/kg, an acute percutaneous LD50 of greater than 2000 mg/kg, and a 1-hr LC50 greater than 633 ppm. These data are compared with published acute toxicity values, and indicate that the predicted acute toxicity of EGBE in humans, based on data from the guinea pig, would be less than that observed in other animal species. Based in part on the guinea pig data, EBGE is no longer classified as a poisonous substance by either the United Nations or US Department of Transportation.     

Differences in the structural characteristics of adult guinea pig and rat cardiomyocytes during their adaptation and maintenance in long-term cultures: confocal microscopy study

In this study, we used laser confocal scanning microscopy and immunofluorescent markers to describe the establishment of long-term (1-5 week) cultures of adult guinea pig cardiomyocytes and adult rat cardiomyocytes. Providing that the preparation of freshly isolated guinea pig cardiomyocytes consists mostly (> 80%) of rod-shaped, Ca(2+)-tolerant, and quiescent cells and these are plated under optimal conditions and density (10(5) cells/cm2), these myocytes have the following characteristics: (1) they remain elongated with regular ultrastructural characteristics and quiescent for 1 week; (2) within 10-14 days, they reestablish intercellular contacts and resume contractile activity, which becomes synchronous all through the confluent layer; (3) their myofibrillar striations remain regular all through the adaptation to culture conditions without any sign of dedifferentiation or redifferentiation; (4) they form adherence junctions (as indicated by their immunoreactivity to an antibody against N-cadherin) over the entire cellular surface; (5) they appear to retain their ability to express atrial natriuretic peptide (ANP), as indicated by immunoreactivity to anti-ANP antibody; (6) this activity seems to be directly related to the surface area of the myocytes in contact with the substrate. In contrast, rat cardiomyocytes cultured under very similar and optimal conditions exhibit very different characteristics during their adaptation in long-term cultures: (1) although 85-90% of freshly isolated cells are also rod-shaped and Ca2+ tolerant they exhibit slow spontaneous contractions; (2) they round up during the first few days, and during the first week they dedifferentiate, losing their regular striated appearance; (3) they spread, becoming irregularly shaped, and, unlike the guinea pig cardiomyocytes, they do not form confluent layers, no matter what the plating density is; (4) they atrophy at a very early stage in the cultures, so that by the fourth week, they have lost most of their myofibrils; (5) the initial rounding up is largely eliminated by exposure for 24 h to 1 microM ryanodine or 20 mM butanedione monoxime, compounds that suppress the spontaneous contractions. In conclusion, our studies demonstrate that adult guinea pig cardiomyocytes adapt and survive in long-term (1-5 week) cultures much better than do adult rat cardiomyocytes, indicating that the long-term cultures of adult guinea pig ventricular myocytes provide a valuable experimental model which opens new possibilities for studying the cellular and molecular regulation of myocardial function under the acute or chronic influence of various intrinsic and/or extrinsic factors.     

Perspective on allogeneic melanoma lysates in active specific immunotherapy

PURPOSE: To compare calcium ionophore-induced cataract formation and in vitro light scattering in cultured lenses from guinea pig and rabbit. METHODS: Lenses from guinea pig and rabbit were cultured for 5 or 6 days with calcium ionophore A23187. To assess the involvement of calpain in cataract formation; SDS-PAGE, immunoblotting and calcium determinations were performed. For in vitro light scattering, lens soluble proteins from rabbit were hydrolyzed for 24 h by either endogenous lens calpain, or by addition of purified m-calpain and then further incubated for up to 10 days. Light scattering was measured daily at 405 nm. RESULTS: Lenses from younger guinea pigs cultured in A23187 first developed outer cortical opacities followed by nuclear cataract. Total calcium was markedly increased by A23187 in lenses of all ages. Proteolysis of crystallins and alpha-spectrin were observed in nuclear cataract in younger guinea pigs. This was attenuated with age, in association with the attenuation of cataract formation with age. Calpain 80 kDa subunit in the lenses cultured with A23187 was also decreased. Co-culture with SJA6017 or E64d (reversible and irreversible inhibitors of calpain, respectively) reduced A23187-induced nuclear opacities, proteolysis of crystallins and alpha-spectrin, and loss of calpain without affecting increased total calcium. In contrast, rabbit lenses cultured in A23187 did not develop nuclear cataract, although biochemical changes in cultured rabbit lenses were similar to those in cultured guinea pig lenses. Furthermore, no appreciable in vitro light scattering occurred in soluble proteins from rabbit lenses after activation of endogenous m-calpain, or after addition of exogenous purified m-calpain, although crystallins were partially hydrolyzed by calpain. CONCLUSIONS: Both rabbit and guinea pig lenses undergo calpain-induced proteolysis upon elevation of lenticular calcium. However, factors in intact guinea pig lenses may promote light scattering and insolubilization after proteolysis by calpain, but these factors were not functional in rabbit lenses. Discovery of the factors promoting light scatter and insolubilization after proteolysis will help to explain the role of certain crystallin polypeptides in cataract formation.     

Inhibition of [3H]norepinephrine uptake in peripheral organs of some mammalian species by ouabain

In order to demonstrate the possible involvement of (Na+ + K+)-ATPase in the high affinity uptake of [3H]-norepinephrine in the sympathetic nerve endings, the effect of ouabain on [3H]norepinephrine uptake in spleen and heart slices of five mammalian species was examined. The ouabain sensitivity of [3H]norepinephrine uptake in the heart slices form various species, as determined by the estimation of IC52, was, in increasing order, lamb (2,3 muM) less than calf (2.5 muM) less than guinea pig (4 muM) less than rabbit (10muM) less than rat (greater than 500 muM). The IC50 values in the spleen slices were: lamb (1 muM) less than calf (3.2 muM) less than rabbit (9.5 muM) less than guinea pig (25 muM) less than rat (greater than 500 muM). The IC50 values for the inhibition of specific [3H]ouabain binding in the microsomal fractions of spleen and heart of the five mammalian species by ouabain were similar to the IC50 values for the inhibition of [3H]norepinephrine uptake by the cardiac glycoside. Since ouabain is known to bind exclusively to (Na+ + K+)-ATPase of a microsomal fraction, these results suggest that the inhibition of [3H]norepinephrine uptake in the sympathetic nerve endings by ouabain is mediated by the inhibition of (Na+ + K+)-ATPase.     

Velocardiofacial manifestations and microdeletions in schizophrenic inpatients

Sigma receptors are found in motor and limbic areas in the brains of humans, non-human primates, and rodents. The most extensive pharmacological studies of ligand binding to sigma receptors have utilized brain tissue from guinea pigs, where two subtypes of sigma receptor, designated sigma1 and sigma2, have been identified. Few functional roles for sigma receptors have been described. Their location in guinea pig striatum, a terminal field of dopaminergic projections arising from the substantia nigra, suggested that this tissue would be a logical choice in which to examine physiological properties of sigma receptor activation. We found that sigma1 receptor agonists inhibited N-methyl-D-aspartate-stimulated [3H]dopamine release from guinea pig striatal slices in a concentration-dependent manner. The inhibition by sigma1 receptor agonists was reversed by a selective sigma1 receptor antagonist, as well as by a non-subtype-selective sigma receptor antagonist. The ability of agonists working through sigma1 receptors, but not through sigma2 receptors, to inhibit the stimulated release of catecholamines appears to be a unique characteristic of guinea pig striatum. We have previously reported that in rat striatum and hippocampus, as well as in guinea pig nucleus accumbens, prefrontal cortex, and hippocampus, activation of either sigma receptor subtype inhibits such release. Stimulated release of [3H]dopamine from guinea pig striatum was also inhibited by the phencyclidine receptor agonist dizocilpine, but this inhibition was not reversed by the sigma receptor antagonists. Therefore, the inhibition produced by sigma receptor agonists was not mediated via the phencyclidine binding site within the N-methyl-D-aspartate-operated cation channel. Our findings support the hypothesis that sigma receptor activation provides a mechanism of modulating dopamine release from striatum, and that striatal tissue from guinea pigs appears to be an appropriate model for characterizing sigma1 receptor-mediated effects.     

Selective cardiodepressant activity of fluodipine, a fluorenone-1,4-dihydropyridine derivative

The effect of the dihydropyridine derivative, 1,4-dihydro-2,6-dimethyl-4-(fluorenon-4-yl)pyridine-3,5-dicarboxyl ic acid diallyl ester (fluodipine) was studied in vitro in different rabbit, rat and guinea pig preparations and in vivo in the rabbit in order to characterize its pharmacological profile at cardiac and at vascular sites. Compared to nifedipine, fluodipine showed a similar cardiodepressant activity, and a much lower inhibitory activity on vascular contraction. The highest tissue selectivity was observed in guinea pig preparations: fluodipine was about 2-3 times more effective than nifedipine on chronotropism and inotropism in isolated atria, and about 150 times less effective on aortic strip contraction. Accordingly, fluodipine (i) showed high-affinity binding to guinea pig ventricular L-type cardiac Ca2+ channels (Ki=2.57 nM), (ii) was about 80 times less effective than nifedipine to inhibit Ca2+ influx in vascular smooth muscle cells and (iii) induced a significant reduction of heart rate in the anesthetized rabbit (ID25=8.5 mg kg(-1), i.v.) without affecting the blood pressure up to 20 mg kg(-1), whereas nifedipine showed a significant hypotensive effect at very low doses (ID25=0.18 mg kg(-1), i.v.). The pacemaker current If of rabbit sino-atrial node myocytes was not affected by fluodipine. These findings demonstrate that fluodipine exerts selective cardiodepressant activity, likely due to a higher affinity for cardiac than for vascular Ca2+ channels.     

Testicular acid phosphatases in cattle, sheep, guinea pig, and rabbit

Acid phosphatase activities were measured with five different substrates in the total homogenates as well as after gel filtration on Sepharose 6B and cellulose chromatography of bull, guinea pig, rabbit, and ram testes. The response of the hydrolysis rate to NaF (5 mmol/l), Co2+ (5 mmol/l) and Zn2+ (5 mmol/l) was also tested. In the total homogenate the hydrolysis of p-nitrophenyl phosphate was markedly activated by Co2+, while in the presence of Zn2+ an activation was recorded in guinea pig and some inhibition in the bull, rabbit, and ram testes. NaF caused a decline in the total acid phosphatase activity, particularly in guinea pig and ram. The gel filtration resulted in three separate activity peaks with p-NPP and beta-NP as substrates. N-ASBI-P, alpha-NP, and Tym-P gave only two peaks. After subsequent cellulose chromatography of the activities only peak II gave rise to two further activities. Peak I of gel filtration (enzyme I) was able to hydrolyze all substrates tested and was highly sensitive to NaF. Peak I of cellulose chromatography (enzyme II) also hydrolyzed p-NPP and beta-NP. It was rather resistant to NaF but sensitive to Zn2+. It was slightly activated by Co2+. Peak II of cellulose chromatography (enzyme IV) hydrolyzed only p-NPP and was markedly activated by Co2+ and Zn2+. The adult testes of bull, guinea pig, rabbit, and ram have a closely similar testicular acid phosphatase pattern. Due to relative differences in the concentrations of the four enzymes in the tissue, varying activity levels are recorded in the presence of different substrate and modifier combinations.     

Antimicrobial and immunological activity of ethanol extracts and fractions from Isopyrum thalictroides

The antimicrobial and immunological properties of ethanol extracts, non-alkaloid, tertiary alkaloid and quaternary alkaloid fractions, obtained from roots and aerial parts of Isopyrum thalictroides were examined. The non-alkaloid fraction from aerial parts inhibited the growth of seven test microorganisms and was the most effective suppressor of classical pathway (CP) complement activity in normal human serum (NHS) and guinea pig serum (GPS). The alkaloid fractions, containing quaternary alkaloids expressed suppressive effect on mitogen-induced splenocyte proliferation. The in vitro antibody response against sheep red blood cells (anti-SRBC) was inhibited by ethanol extracts and quaternary alkaloid fraction. The intraperitoneal (i.p.) application of ethanol extract and tertiary alkaloid fraction from aerial parts showed that they possess in vivo effect on alternative pathway (AP) complement activity, anti-SRBC response and delayed type hypersensitivity (DTH).     

Mammalian transcobalamin II metabolism. The immunological and the biological cross-reactivity of mammalain transcobalamin II

Assay of the reactivity between the chicken anti-rabbit transcobalamin II antiserum and the sera of 19 vertebrate species was carried out by both immuno-diffusion and Sephadex G-200 gel filtration column chromatography. Mammalian transcobalamin II cross-reacted with the antiserum whereas the serum vitamin B-12 binders of the bird, amphibian reptile and fish did not. The biological activity of the purified rabbit transcobalamin II was assessed using reticulocytes or erythrocytes of human, rabbit, guinea pig and rat. The purified rabbit transcobalamin II promoted the uptake of vitamin B-12 by the cells but showed a great variation in its activity. It is suggested that the rabbit transcobalamin II is immunologically and biologically similar to the serum transcobalamin II of the mammalian species studied.