Showing papers in "Life Sciences in 1990"

TL;DR: A mathematical framework was developed to provide a quantitative basis for either in vivo tissue or in vitro microdialysis, and the importance of metabolism and efflux to the microvasculature is illustrated by the wide variation in predicted tissue concentration profiles.

TL;DR: The results indicate that unique structural requirements exist for each transporter site, but that cocaine binding at norepinephrine and dopamine transporters can be described by more similar structure-activity relationships than those found for the serotonin transporter.

TL;DR: M3G, the major plasma and urinary metabolite of morphine, was shown to be a potent antagonist of morphine analgesia when administered to rats by the intra-cerebroventricular (i.c.v.) route.

TL;DR: Information suggests that mast cells may serve as a link between the immune, endocrine and nervous systems and could have an important role in the access of lymphocytes and pathogens to the brain.

TL;DR: The results of the re-analysis indicated that response requirement and reinforcer magnitude, the constituents of unit price, have functionally equivalent effects on drug consumption and that a positively decelerating demand curve is produced as unit price increases.

TL;DR: It is concluded that galanthamine does not accumulate in large amounts in red blood cells, and there was no difference between enzyme inhibition by galanthamines in whole blood and separated fractions of plasma and erythrocytes.

TL;DR: In the model of acute renal failure which was induced by occlusion of the bilateral renal arteries of rats followed by reperfusion, ET-monoclonal antibody improved the renal function and protected the kidneys from renal proximal tubular necrosis and suppressed Ca++-accumulation in necrotic tissues.

TL;DR: Structural/activity analysis indicates, however, that RTX and related homovanillyl-diterpene esters display distinct spectra of activity, providing the first direct proof for the existence of vanilloid receptors.

TL;DR: The significance of the stress-induced decrease of PRL does not appear to have a major consequence on the physiology of reproduction in the rat and it is suggested that future studies be directed towards its significance in the immune system.

TL;DR: Positron emission tomography was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow in humans and found that pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease.

TL;DR: In the neonatal rat, as in the chicken embryo, D-aspartic acid continued to increase in the retina after that in the brain and other tissues had begun to decline, showing that release from a bound form or de novo synthesis is a continuing process during development.

TL;DR: This modification of the catechol-O-methyltransferase (COMT) based radioenzymatic assay for norepinephrine (NE) and epinephrine (E) improves sensitivity, selectivity and eliminates many inhibitors of COMT.

TL;DR: Surprisingly, consistent and reproducible levels were found in microdialysis levels, with the only exception being one patient on 1-DOPA therapy who had elevated DA and metabolite levels.

TL;DR: The effect of l-deprenyl on longevity was examined in male Fischer rats, showing a significant increase in both mean and maximum survival and suggesting that an earlier onset for treatment may be beneficial.

TL;DR: Of the central neural tissues examined, the suprachiasmatic nuclei are most frequently mentioned as a location for melatonin binding sites although binding seems to be widespread in the brain.

TL;DR: It is concluded that DHEA protects against at least one GC anti-immune effect, thymic lymphocyte lysis, in vivo and in vitro.

TL;DR: Levels of cytochrome P-450 IIIA4 vary widely among individuals and can explain the variation in rates of 17 alpha-ethynylestradiol 2-hydroxylation, and the progestogen gestodene appears to be unusually active in this regard.

TL;DR: The contractile ability of cocaine and its major metabolites in isolated cat cerebral arteries was evaluated and benzoylecgonine was a potent contractile agent, causing a 50% decrease in cross sectional area at 10(-5) M.

TL;DR: Findings provide evidence that NAN-190 acts as a mixed agonist/antagonist at central 5-HT1A receptors and further emphasizes the difference between pre- and postsynaptic 5- HT1A receptor-mediated events in brain.

TL;DR: It is suggested that 5- HT-1A and 5-HT-2 receptor sites are important in the serotonergic modulation of haloperidol-induced catalepsy.

TL;DR: The results revealed that the intracerebral dialysis technique provides a useful method to monitor changes in spontaneous neurotransmitter release during the sleep-waking cycle.

TL;DR: It is suggestive that MDMA administration increases DA release in the striatum of awake, freely-moving rats, and MDMA-induced increase in the extracellular concentration of DA in the Striatum is mediated, in part, via 5-HT2 receptor mechanisms.

TL;DR: The author suggests that type 2 agents may antagonize the effects of cocaine, and might prove useful in the treatment of cocaine addiction.

TL;DR: The α 1 AR-mediated positive inotropic effect seen in isolated heart preparations appears to involve increased Ca sensitivity of myofibrils and production of inositol triphosphate (IP 3 ) and diacylglycerol (DAG), but the functions of IP 3 and DAG are not clear.

TL;DR: The results do not support the idea that zinc deficiency is a common contributory factor of HIV infectivity or clinical expression, nor that HIV infection induces a zinc deficiency.

TL;DR: Intracerebral injections of the broad spectrum excitatory amino acid antagonist kynurenic acid (50 ug) alleviated the symptoms of akinesia, tremor and rigidity in a severely parkinsonian monkey.

TL;DR: Magnolol is an antiplatelet agent isolated from Chinese herb magnolia officinalis as mentioned in this paper, which is used to relax vascular smooth muscle by releasing endothelium-derived relaxing factor (EDRF) and by inhibiting calcium influx through voltage-gated calcium channels.

TL;DR: In some tissues, the pharmacology of GABA-induced actions is quite atypical and should be further explored with the newer ligands and modulators for GABAA- and GABAB-receptors.

TL;DR: It is indicated that met-enkephalin suppresses astrocyte growth in culture and causes a significant decrease in both total cell numbers and [3H]-thymidine incorporation by GFAP-positive cells with flat morphology.

TL;DR: K+ channel activators are potent vasorelaxant and cardioprotective agents possessing an original mechanism of action which is the opening of plasmalemma ATP-regulated K+ channels.