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Biomedical subjects

W Dairman

Publications and source records attributed to W Dairman.

At least 19 recordsLinked to original sources
PubMed1989

Effect of exogenous pyruvate on acrylamide neuropathy in rats.

The protective effect of exogenous sodium pyruvate on the distal-proximal progression of experimental acrylamide neuropathy in rats was examined. Incorporation of 2% (w/w) sodium pyruvate powder in the diet of rats receiving subcutaneous injections of an aqueous solution of acrylamide (35 mg/kg/day, 5 days/week) retarded the onset and development of functional, morphological, and biochemical measures of acrylamide neuropathy. Pyruvate supplementation did not alter hexobarbital sleep time or zoxazolamine paralysis time, two in vivo measures of microsomal mixed-function oxidase activity, and the disposition of radioactivity in plasma or sciatic nerve following subcutaneous injection of [14C]acrylamide. Although acrylamide can interfere with energy metabolism at a variety of sites where pyruvate can rescue neurons (axons), the data of this study are consistent with our earlier hypothesis that acrylamide neuropathy may be associated with a glycolytic deficit. The exact site of pyruvate protection is unknown. Exogenous pyruvate is perhaps utilized by axons to circumvent toxin-induced glycolytic inhibition and provide chemical energy for fast axonal transport.

Acrylamide↗
PubMed1981

(--)-threo-Chlorocitric acid: a novel anorectic agent.

A new class of peripherally acting anorectics is described in these studies. The four stereoisomers of chlorocitric acid which are structurally similar to the known anorectic, (--)-threo-hydroxycitric acid, all suppressed food intake when administered at high doses to rats. Only one of these isomers, (--)-threo-chlorocitric acid, retained its anorectic activity at lower doses. The anorectic potency of (--)-threo-chlorocitric acid was approximately 40-fold greater in dogs than in lean and obese rats. The decreased food intake in rats resulted in a significant reduction of body lipid, without affecting protein levels. In contrast to the tolerance which was observed with the continued administration of mazindol or diethylpropion, tolerance to the anorectic effect of (--)-threo-chlorocitric acid did not develop. These studies suggest that (--)-threo-chlorocitric acid might be useful as an antiobesity agent.

Animals↗
PubMed1974

Decarboxylation to tyramine: a major route of tyrosine metabolism in mammals.

Metabolism of tyrosine was examined in mice, some of which had been treated with an inhibitor of aromatic-L-amino-acid decarboxylase. The results of the study indicate that as the plasma and tissue levels of tyrosine are elevated, decarboxylation to tyramine becomes the predominant route of metabolism. At the highest dose of tyrosine used (1.5 g/kg), it was found that 42% of the administered dose was decarboxylated within 6 hr and only 11.5% was metabolized by the tyrosine aminotransferase pathway.

Animals↗
PubMed1972

On the identity of DOPA decarboxylase and 5-hydroxytryptophan decarboxylase (immunological titration-aromatic L-amino acid decarboxylase-serotonin-dopamine-norepinephrine).

Simultaneous immunological titration of DOPA and 5-hydroxytryptophan decarboxylase activities, from a number of tissues of various species, showed that the two activities were not distinguishable with a monospecific antiserum to hog kidney decarboxylase. Together with previous findings, these data firmly establish the concept that in mammalian tissues the two enzyme activities are associated with a single protein, namely aromatic L-amino acid decarboxylase.

5-Hydroxytryptophan↗
PubMed1972

Catecholamine concentrations and the activity of tyrosine hydroxylase after an increase in the concentration of tyrosine in rat tissues.

The concentrations of tyrosine in rat plasma and brain were increased 2-7 fold by the administration of either L-tyrosine or cycloheximide. Under these conditions catecholamine concentrations in the brain and the heart remained unchanged even when the rats were maintained in a cold environment to increase catecholamine turnover. The data are interpreted to mean that an increase in the tyrosine concentration in the tissues does not result in an in vivo substrate inhibition of tyrosine hydroxylase.

Animals↗