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Biomedical subjects

J Chakraborty

Publications and source records attributed to J Chakraborty.

At least 181 records · Page 10Linked to original sources
PubMed1976

The effect of some glucocorticoids on hepatic microsomal hydroxylation in the rat and hamster.

The effect of some glucocorticoids on hepatic microsomal biphenyl and aniline hydroxylations were investigated in rat and hamster. Steroids were either added to the standard incubation mixture or given as a single dose intraperitoneally before preparation of the liver microsomes for enzyme determination. The addition of steroids in vitro enhanced biphenyl-2-hydroxylation activity in hepatic microsomes of rat but not of hamster and the most pronounced effect was obtained with betamethasone. A similar species difference in the effects of betamethasone on this enzyme was also observed after administration of a single dose of the steroid in vivo.

Aniline Hydroxylase↗
PubMed1976

The circadian variation of hepatic microsomal drug and steroid metabolism in the golden hamster.

Rhythmic variations in a number of parameters of hepatic microsomal drug and steroid metabolism and binding were observed in the adult male golden hamster. With an illumination schedule of a light phase between 06.30 and 18.30 h, maximal activities were encountered between 04.00 and 08.00 h with corresponding minima between 16.00 and 18.00 h. In addition, kinetic changes were observed in both the metabolism and spectral interaction of aniline and biphenyl at times of maximal and minimal activities. Possible mechanisms responsible for the circadian variation in hamster hepatic microsomal xenobiotic metabolism are discussed.

11-Hydroxycorticosteroids↗
PubMed1976

A radioimmunoassay method for prednisolone: comparison with the competitive protein binding method.

Cross reactivity of prednisolone with an antiserum raised against dexamethasone-21-hemisuccinate conjugated with bovine serum albumin was utilized to develop a radioimmunoassay for prednisolone in unextracted plasma. The results are in good agreement with those obtained with a standard competitive protein binding method employing prior extraction and separation of the synthetic from endogenous steroids.

Humans↗
PubMed1976

The effect of some polyene macrolides on absorption from the small intestine in the rat.

The effect of three polyene macrolides, candicidin, amphotericin B and nystatin on the absorption of [3H] cholesterol was studied in the rat by using the in situ gut loop perfusion technique. Chronic treatment with candicidin and its presence at various concentrations in the gut loop perfusion experiments inhibited [3H] cholesterol absorption although a smaller effect was also obtained with amphotericin B and nystatin at higher concentrations. A similar but much less pronounced action of candicidin was also observed on the absorption of [3H] corticosterone and [14C] phenytoin.

Amphotericin B↗
PubMed1976

Effect of cadmium on spermatogenesis in toad (Bufo melanostictus).

A quantitative study of seminiferous tubules in toad treated with a single subcutaneous injection of cadmium chloride, showed that 7 days after cadmium injection some stages of spermatogenesis consisting of secondary spermatogonia and primary spermatocytes were decreased significantly.

Animals↗
PubMed1975

A radioimmunoassay procedure for dexamethasone: plasma and urine levels in man.

A sensitive and precise dexamethasone radioimmunoassay method was applied to the determination of dexamethasone levels in the plasma and urine of human subjects who had received small doses of the drug by mouth. While the method can be applied directly to plasma, urine has to be diluted before assay. Very little cross-reaction was observed with two possible metabolites of dexamethasone. Both in the healthy subjects and in the group of patients investigated rapid absorption of dexamethasone from the gastrointestinal tract was observed. However, there appeared to be a large individual variation in the plasma concentration of the drug obtained after doses of the same size.

Adult↗
PubMed1975

Prednisolone levels in the plasma and urine: a study of two preparations in man.

1. A competitive protein binding method was used to measure prednisolone and cortisol in blood and urine of volunteers given prednisolone by mouth (15 mg) in the standard tablet form and a fortnight later a regulated release formulation of prednisolone metasulphobenzoate containing an equivalent amount of prednisolone. 3. Plasma prednisolone levels rose rapidly after the standard tablet and more slowly after the regulated release form. The normal activity of the hypothalamic-pituitary-adrenal axis as measured by the 09.00 h plasma cortisol concentration was present 24 h after ingestion of the regulated release preparation. In contrast, the 09.00 h plasma cortisol level was reduced in subjects 24 h after receiving prednisolone in the standard tablet form.

Adult↗