摘要:

AbstractThe sodium dependence of high affinity glutamic acid transport has been studied in cortical synaptosomes from Sprague‐Dawley rats and compared to previous studies with Long‐Evans rats. Initial velocity of uptake was measured as a function of both glutamate and sodium concentration, and the data fitted to the rate equations for the same set of models that was utilized in the Long‐Evans studies. The minimal best‐fit model was found to be identical to that found previously for Long‐Evans animals. Thus there are no fundamental differences in the basis of the sodium dependence of high affinity glutamate transport between the two groups.However, since the constants describing the best fit model are different for the two groups of animals, there are quantitative differences in the transport mechanism between the two groups. The rate equation for the minimal best‐fit model permits certain functions to be defined in terms of dissociation and translocation constants, substrate, sodium, and total carrier concentrations. These functions were calculated and then utilized to demonstrate the quantitative differences in the transport mechanism in the

ISSN:0360-4012    

DOI:10.1002/jnr.490060202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractAn antibody secreting cell line has been obtained using the technology developed by Milstein, Kohler, and colleagues by fusion between ×63 myeloma cells and spleen cells from a mouse previously immunized with PC12 cultured rat pheochromocytoma cells. This antibody bound to particulate protein from adult rat brain and to a lesser extent spinal cord and retina but not adrenal. Lower levels of binding were observed also with spleen, bone marrow, and peritoneal exudate cells. Cells or particulate protein from seven nonneural, nonimmune tissues showed essentially no specific binding. Analysis of adherent and nonadherent peritoneal exudate cells indicated specific antibody binding to both populations. The specific antibody bound was greater in the non‐adherent fraction. The antigen has been provisionally named G5 after the antibody secreting clone. Like the Thy 1 antigen of rodents, it is expressed by subpopulation of cells from the nervous and immune systems. However the antigen could not be detected on the PC1 2 cell line used for immunization suggesting that Balb/C mice spontaneously produce antibody to this rat differentiation antig

ISSN:0360-4012    

DOI:10.1002/jnr.490060203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractG5‐IgG is a monoclonal antibody that binds specifically to some cells and tissues of the adult rat nervous and immune systems. The molecular nature of the G5 antigen from adult rat brain is described in this paper. G5 antigen in adult rat brain membrane fractions was trypsin‐sensitive and heat‐labile but not chloroform/methanol‐soluble. It was solubilized by the nonionic detergent NP40 but not by 3 M KCl. Detergent‐soluble rat brain particulate protein inhibited G5‐IgG binding to glutaraldehyde‐fixed rat brain particulate protein. Inhibitory activity could be removed by prior incubation with concanavalin‐A agarose beads. Immunoprecipitates of enzymatically iodinated, detergent‐solubilized brain particulate protein gave a single band on polyacrylamide gels of apparent molecular weight 95,000–105,000 daltons. A band of identical molecular weight was visualized in gels of unlabeled immune precipitates by125I‐concanavalin A. These results strongly suggest that G5 is an integral membrane glycoprote

ISSN:0360-4012    

DOI:10.1002/jnr.490060204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractDihydropteridine reductase was purified approximately 1,700‐fold from human outdated blood platelets. Two forms of the enzyme, A and B, were resolved. They have the same Kmvalues for 2‐amino‐6,7,‐dimethyl‐4‐hydroxydihydropteridine (46 μml;M vs 49 μml;M), but the A form has a Kmfor NADH that is two times higher than that of the B form (20 μml

ISSN:0360-4012    

DOI:10.1002/jnr.490060205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe metabolism of myelin glycerophospholipids as a function of essential fatty acid (EFA) deficiency was studied in rats. Mothers were fed a lipid‐free diet from the eighth day of pregnancy throughout the suckling period. Pups were continued on the diet after weaning. Control mothers and pups were fed the same diet as experimental rats plus 3% corn oil for the same periods. Pups fed the lipid‐free diet had lower total body weight, brain weight, and total myelin phospholipid levels than controls.At 17 days of age, each rat pup was injected with a mixture of [3H]‐glycerol and [1‐14C]‐acetate and were killed up to 80 days after injection. Lipids were extracted from isolated myelin. The3H/14C ratio for choline, serine, and ethanolamine glycerophospholipids decreased more slowly in experimental rats than in controls, suggesting an alteration in either the turnover of myelin phospholipids or the recycling of phospholipids into myelin. Radiolabelled acyl moieties were isolated from myelin lipids and separated according to the degree of unsaturation. Acyl groups with three double bonds, presumably 20:3 (ω−9), isolated from EFA‐deficient rats appeared to be synthesized from a long‐lived pool of precursor. The relative synthesis of other unsaturated acyl moieties appeared to be the same in both groups of rats. These results indicate that EFA deficiency affects m

ISSN:0360-4012    

DOI:10.1002/jnr.490060206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractNerve growth factor (NGF), epidermal growth factor (EGF), adenosine 3′,5′‐cyclic monophosphate (cAMP), and cholera toxin all increase the specific activity of ornithine decarboxylase (ODC) in the PC12 nerve‐like cell line. A phosphodiesterase inhibitor augments the effect of NGF on the induction of ODC in these cells, while it is only additive with the EGF response. These data suggest that cAMP has an intermediary role in the induction of ODC by NGF and that cAMP is not involved in the EGF r

ISSN:0360-4012    

DOI:10.1002/jnr.490060207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractSimultaneously with an evoked release of endogenous glutamate, redox changes in NAD(P)H levels occur as a response to electrical or chemical stimulation of the isolated CNS tissue. While electrical‐field stimulation induces a transient increase in tissue NAD(P)H, KCl stimulation produces a decrease in NAD(P)H. One possible interpretation for this difference is that elevated KCl induces glutamate release from larger cell populations, including glia, while electrical stimulation might have a more neuro‐specific action. In the present report, it is shown that the electrically or biochemically evoked release of endogenous glutamate is strongly inhibited by ammonium ions at 3–5 mM in the hippocampus and frontal cortex. At the same time, ammonium ions inverted the NAD(P)H response of the tissue during electrical stimulation, making both electrical and KCl depolarization induce a decrease in NAD(P)H. There was no effect of ammonium ions per se on the NAD(P)H levels, and to obtain the effects on both NAD(P)H and glutamate release, the tissue had to be exposed for 40–60 minutes to ammonium ions. The results are interpreted to indicate that ammonium ions influence regulatory control mechanisms in cell populations in the tissue slice that secretes glutamate in response to depolar

ISSN:0360-4012    

DOI:10.1002/jnr.490060208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractData from a study in which 12 chronic mental patients and 12 control subjects were given D‐[3‐14C] glucose intravenously in our arterio‐venous technique for determining cerebral metabolism in vivo were reexamined. Previously unpublished whole‐blood lactate determinations in these experiments indicated a cerebral production of much higher specific activity of [1‐14C]‐lactate from the D‐[3‐14C] glucose by mental patients. Of several possible explanations offered for this difference, the most likely was that involving a small lactate compartments(s) in some specific region(s) in which decarboxylation of the endogenously formed cerebral lactate was partially inhibited. Two other experiments with mental patients (one given [U‐14C] glucose and the other, [1‐14C] glucose) whose extraordinary results were described, in part, in a previous report, were interpreted as more extreme examples of the production of higher specific activity14C‐lactate from14C‐glucose by mental patients' brains upon their very unusual w

ISSN:0360-4012    

DOI:10.1002/jnr.490060209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractElectrocortical activity was recorded in encéhale isolé rats during injection of various dopaminergic compounds into the caudate nucleus. Slow waves and spindles were observed following injection of compounds with different mechanisms of action in stimulating the dopamine receptor. Some arylalkylamine analogues also induced similar electrocortical changes, whereas others were inactive. The possible dopamine agonist activities of these compounds are discussed. The results support an involvement of dopamine in the production of electrocortical slow waves and spindle

ISSN:0360-4012    

DOI:10.1002/jnr.490060210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe present study investigated the effects of unilateral right or left cervical vagotomy, selective subdiaphragmatic transection of the anterior vagal trunk, the posterior vagal trunk or the hepatic branch of the vagus, and the effects of total abdominal vagotomy with concomitant pyloroplasty on the regulation of spontaneous ingestive behavior and responsiveness to osmotic and volemic challenges. Total abdominal vagotomy with pyloroplasty somewhat reduced food intake, water consumption, and body weight measured ten weeks postsurgery. The other denervation procedures did not affect these parameters of spontaneous ingestive behavior. In additional tests given approximately two and four months postsurgery, rats that had undergone total abdominal vagotomy exhibited a significantly longer latency to drink and consumed less water than controls during the initial 0.5 hours after injection of hypertonic saline. These total abdominally vagotomized rats also exhibited significantly lower cumulative physiological saline intake in comparison to controls for 4, 8, and 16 hours after subcutaneous injection with polyethylene glycol, but not 2 or 24 hours postinjection. However, total abdominal vagotomy did not impair water drinking one, two, or four hours after injection with D,L‐isoproterenol (0.04–0.32 mg/kg body weight). The other denervation procedures did not alter drinking in response to isoproterenol or polyethylene glycol injections, and most of these groups exhibited normal latency and intake following injection of hypertonic saline. The hepatic vagotomy group, however, exhibited a shorter latency to drink in response to hypertonic saline injection than controls. The present results demonstrate that spontaneous food and water intake, body weight, and responsiveness to various volemic and osmotic regulatory challenges are clearly impaired only by the total abdominal vagotomy proced

ISSN:0360-4012    

DOI:10.1002/jnr.490060211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY