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Biomedical subjects

G D Kalyankar

Publications and source records attributed to G D Kalyankar.

9 recordsLinked to original sources
PubMed1986

Effect of adrenalectomy on gamma-aminobutyric acid concentrations in the central nervous system.

Pyridoxal-5'-phosphate (PLP) plays a crucial role in regulating the steady-state levels of gamma-aminobutyric acid (GABA) in CNS. Adrenalectomy resulted in decreased conversion of dietary vitamin B6 to PLP. As a consequence of this, GABA levels in cerebral cortex decrease, since synthesis of GABA is determined by glutamate decarboxylase, a PLP-dependent enzyme. Feeding diet supplemented with vitamin B6 elevated the GABA levels in adrenalectomized animals, because of increased availability of the coenzyme for apodecarboxylase. The data suggest a role for corticosteroids in maintaining GABA levels, through their effects on PLP formation.

Adrenalectomy↗
PubMed1984

Effect of steroid hormones on age dependent changes in rat arginase isoenzymes.

Age dependent changes in rat liver and kidney arginase isoenzymes from day 1 to 73 weeks have been studied. It has been observed that total liver arginase activity (activity/liver) increases with age, but there is no appreciable change in the proportions of isoenzymes, their pH optima, electrophoretic mobilities and inhibition characteristics, although Km increases with age. Corticosterone induces liver arginase activity and the degree of induction decreases with age. The hormone has no effect on kidney arginase. Testosterone treatment, on the other hand, induces kidney arginase without any effect on liver enzyme.

Age Factors↗
PubMed1983

Influence of adrenalectomy on vitamin B6 status.

Adrenalectomy results in depletion of vitamin B6 stores. This depletion is rapid and significant in liver, as compared to brain. When the adrenalectomized rats are fed with excess vitamin B6 or injected with corticosterone, the normal vitamin levels are maintained. Thus, it is possible that adrenocortical hormones help in the retention of vitamin B6 in the body.

Adrenalectomy↗
PubMedDate not supplied

Effect of steroid hormones and vitamin B6 on age dependent changes in aminotransferases in rat.

Experiments have been carried out on liver and Kidneys to study the age dependent changes in alanine and aspartate aminotransferases and the influence of steroid hormones corticosterone (catabolic), testosterone (anabolic) and vitamin B6 on these changes. The rats used were of the ages between 7 to 73 weeks. It is observed that specific activity of alanine aminotransferase as well as the activity per liver increased with age. The same is true with the kidneys. Corticosterone treatment brings about two and half fold increase in activity in the liver of younger rats, whereas there is only 25% increase in the oldest group. Testosterone and vitamin B6 lower this activity, the latter showed more pronounced effect. In the case of kidneys the changes are marginal. Aspartate aminotransferase shows marginal changes in the specific activities in both liver and kidney, whereas the total activity increases with age, except in the case of liver where there is decrease at 73 weeks. Both testosterone and vitamin B6 have marginal influence on the kidney enzyme. There is no apparent explanation for the differential behaviour of the two enzymes.

Aging↗