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Biomedical subjects

S A Nevagi

Publications and source records attributed to S A Nevagi.

11 recordsLinked to original sources
PubMed2005

Efficacy of HCG and ovarian steroids in the maintenance/interruption of pregnancy in-albino rats.

We investigated the efficacy of human chorionic gonadotrophin (HCG) and ovarian steroids in the maintenance/interruption of pregnancy in normal pregnant rats. Holtzman's strain rats were laparotomized to observe the number of implantations. In this study, continuous administration of HCG (5 IU) to normal pregnant rats, from day 8 through days 14 or 19, interrupted gestation, resulting in fetal resorption with many placentomas and placental scars. By contrast, a single injection of HCG (5 IU or 1 IU) on day 8 had no deleterious effect on pregnancy, except that the percent fetal survival was slightly reduced, attributable to a slight hyperstimulation of the ovaries of the pregnant rats. One possibility is that prolonged treatment with HCG might have caused progesterone/luteal hormone deficiency with a concomitant increase in estrogen secretion, resulting in the interruption of pregnancy. Hence, here we tested whether progesterone (5 mg) or estradiol-17beta (1 microg) administered to HCG treated rats could compensate this deficiency and maintain pregnancy. The results indicate that these steroids cannot prevent the interruption of pregnancy induced by the continuous administration of HCG, possibly due to an overstimulation of the ovaries by gonadotrophin.

Adrenal Glands↗
PubMed2004

Maintenance or interruption of pregnancy by human chorionic gonadotrophin in adrenalectomized albino rats.

In the present study, we investigated the efficacy of human chorionic gonadotrophin (HCG) in the maintenance of pregnancy in adrenalectomized rats. Holtzman's strain albino rats were adrenalectomized on day 8 of pregnancy and at the same time were laparotomized to observe the number of implantations. Adrenalectomy on day 8 caused abortions or fetal resorption in almost all rats. Administration of 5 or 50 IU HCG in adrenalectomized rats, from day 8 through 14 or 19, was not able to maintain gestation, resulting in fetal resorption with many placentomas and placental scars. However, a single injection of 5 IU or 1 IU HCG administered on day 8 only maintained the pregnancy to full term in adrenalectomized rats. Hence, the present experiment indicates that replacement therapy of a single dose of 5 IU or 1 IU HCG might be sufficient for maintaining pregnancy in adrenalectomized rats.

Adrenalectomy↗
PubMed2004

Molecular phylogeny in 3-D.

Molecular phylogenetic trees are constructed in three dimensions relative to the distribution of MW and pl classes and immunocrossreactivity against polyclonal antibodies to lens crystallins, as well as multiple sequence alignment between amino acid sequences, coding nucleotide sequences and the gene nucleotide sequences for beta-globin. Euclidian distances are estimated to position species in x, y, z space by multidimensional scaling and merged with bootstrap-tested branching pattern of Fitch & Margoliash plots to obtain 3-D phylogenetic tree. Compared to single attributes, phylogenetic trees based on multiple parameters allow significant repositioning of rodents, chiroptera and primates.

Animals↗
PubMed2001

Effect of dexamethasone on implantation and pregnancy in albino rats.

Administration of 3 mg/kg body weight of dexamethasone from day 1 or 3 to 7 of pregnancy did not prevent implantation in albino rats. But the same dose when administered from day 8 to 11 resulted in complete abortion / resorption in all rats. Administration of 2 mg / kg body weight of dexamethasone from day 8 to 11 of pregnancy held no effect on the foetal survival. The results indicate that a high dose of dexamethasone does not affect implantation but the same dose affects the more advanced stages of pregnancy.

Animals↗
PubMed1987

The effect of progesterone and progestational antiandrogen cyproterone acetate on the ovaries and the adrenal glands of neonatally androgenised rats.

The influence of the graded doses of progesterone and progestational antiandrogen, cyproterone acetate, is studied on the vaginal cycles, follicular dynamics and steroidogenic potential of the ovaries and adrenal glands in neonatally androgenised rats with persistent vaginal estrous. Of the different doses of progesterone, 0.5 mg progesterone/day is found to reinstate more or less normal vaginal cycles. None of the doses of progesterone and CPA induced ovulation in cystic ovaries and hence the vaginal cycles thus reinstated are not the reflection of ovarian cycles and the diestrous smear is not an indication of functional CL in these ovaries. The treatment of progesterone and CPA brought about degenerative changes in the antral follicles above stage IV and in cystic type I follicles. It mobilised the growth of type 0 follicles up to the early antral stage of type III, thereby indicating the presence of the negative feedback of progestational steroids on FSH secretion in PVE rats. The minimum change in the activity of carbohydrate metabolising enzymes and the steroid dehydrogenases in the ovaries subsequent to the treatment with especially the higher doses of progesterone, and CPA suggests the absence of any impact on LH secretion, albeit indirect. There was a marked reduction in the steroidogenic potential in the adrenal glands of the CPA treated rats; however, it did not show any positive impact on the structure of the polycystic ovary.

Adrenal Glands↗
PubMed1983

Induction of ovulation and spawning in the catfish, Clarias batrachus (L.) by prostaglandin F2 alpha.

Administration of low doses of prostaglandin F2 alpha (PGF2 alpha), i.e. 10 and 100 ng/g b.wt, was ineffective in inducing ovulation and spawning in mature catfish. However, doses of 200 ng/g b.wt of PGF2 alpha elicited partial response, and 500 ng/g b.wt of PGF2 alpha induced profuse ovulation and spawning similar to that induced by administration of human chorionic gonadotropin (HCG).

Animals↗