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Biomedical subjects

R S Prasad

Publications and source records attributed to R S Prasad.

14 recordsLinked to original sources
PubMed1987

A new non-hormonal antifertility drug DL-204: I. Effects on testes and accessory glands of reproduction in male rats.

The effect of DL-204, 2-(3-ethoxyphenyl)-5,6-dihydro-5-triazole (5,1a)-isoquinoline, a non-hormonal post-implantational anti-fertility drug, on tissue weights, nucleic acids and total protein concentrations in the testes, ventral prostate and seminal vesicles were evaluated in immature and sexually mature rats, while changes in DNA synthesis were studied only in the immature rats. Treatment of 21-day-old rats at doses of 5mg and 10mg/kg bw once daily for 15 days had no effect on body weight but reduced the weights of testes and accessory glands of reproduction. The concentration of DNA increased while RNA and protein decreased significantly. Treatment of adult rats with DL-204 at a dose of 10mg/kg bw had no effect on body and testes weights but reduced ventral prostate and seminal vesicle weights. The concentration of RNA and protein decreased significantly, while DNA concentration was not altered. DL-204 treatment resulted in drastic decrease of RNA/DNA ratio, reflecting ribosomal loss and cytoplasmic shrinkage. The effects observed after DL-204 treatment are comparable to post-castration changes. DL-204 may be acting on testes and accessory reproductive organs by blocking androgen biosynthesis and/or by antagonizing the action of androgens. It may be acting directly on the normal function of the hypothalamo-pituitary-gonadal axis.

Animals↗
PubMed1987

A new non-hormonal antifertility drug DL-204: II. Effect on testicular hyaluronidase and gamma-glutamyl transpeptidase in male rats.

Effects of DL-204, 2-(3-ethoxyphenyl)-5,6-dihydro (5,1-a)-isoquinoline, a non-hormonal antifertility drug on testicular hyaluronidase and gamma-glutamyl transpeptidase levels, biochemical markers for testicular function, were evaluated in male rats. Treatment of 21-day-old rats with DL-204 for 7 or 15 days produced cryptorchid condition. Testicular hyaluronidase and gamma-glutamyl transpeptidase levels reveal that DL-204 acts on the testes, possibly in two ways; one, by reducing the gonadotropin levels thereby reducing the levels of androgens as reflected by reduced accessory reproductive organ weights and, secondly, by a direct action on the testes. Thus, we conclude that DL-204 is acting as an antispermatogenic agent, possibly acting in more than one way on the testes.

Age Factors↗
PubMed1986

A new non-hormonal antifertility drug DL 111-IT: I. Effects on testes and accessory glands of reproduction in male rats.

Effect of DL-111, 3-(2-ethylphenyl)-5-(3-methoxyphenyl-1H-1,2,4-triazole, a non-hormonal postimplantational antifertility agent, on testicular and accessory reproductive organ weights and total protein, RNA and DNA concentrations were evaluated in immature and adult rats. Treatment of 21-day-old rats at doses of 2.5 mg and 5 mg/kg body weight decreased body weight, weights of testes and accessory glands of reproduction. RNA and protein concentrations decreased significantly with significant increase increase in DNA concentration in testes, epididymis, ventral prostate and seminal vesicles. DL-111 treatment of adult rats at doses of 5 mg and 10 mg/kg body weight had no effect on body weight, but significantly decreased weights of testes and accessory glands of reproduction. RNA and protein concentrations decreased significantly in all tissues studied while DNA concentration was not altered. RNA/DNA ratio decreased significantly, reflecting ribosomal loss and cytoplasmic shrinkage. These effects of DL-111 are comparable to post-castrational changes in accessory glands of reproduction. We presume that these changes are mediated by blocking the androgen biosynthesis and/or by interfering with normal function of hypothalamo-pituitary-gonadal axis.

Abortifacient Agents↗
PubMed1986

A new non-hormonal antifertility drug DL 111-IT: II. Effects on testicular hyaluronidase activity in male rats.

Effects of DL-111, [3-(2-ethylphenyl)-5-(3-methoxyphenyl-1H-1,2,4-triazole] a non-hormonal antifertility agent, on testicular hyaluronidase activity, an accurate biochemical marker for testicular function, were evaluated in male rats. Treatment of 21-day-old rats with DL-111 sc for 7 or 15 days resulted in a significant fall in testicular weight and complete suppression of hyaluronidase activity. During the 30-day post-treatment the enzyme activity was restored to normal levels. Treatment of 40-day-old rats for 7 or 15 days also produced a significant decrease in testicular weight and hyaluronidase activity. Simultaneous administration of LH, PMSG or T with DL-111 to 21-day-old rats blocked the inhibitory activity of the drug as the enzyme activity was restored to untreated control levels. Administration of FSH along with DL-111 had no effect on suppressive action of the drug. These results suggest that in male rats DL-111 inhibits testicular activity by reducing LH levels, thereby reducing T levels as observed by reduced weights of testes and accessory glands of reproduction and hyaluronidase activity.

Abortifacient Agents↗
PubMed1976

Studies on host-flea relationship. IV. Progesterone and cortisone do not influence the reproductive potentials of rat fleas Xenopsylla cheopis (Rothschild) and X. astia (Rothschild).

Experiments carried out to study the influence of progesterone and cortisone on the initiation of ovarian maturation, fecundity rate and fertility of the two species of rat fleas Xenopsylla cheopis (Rothschild) and X. astia (Rothschild) indicated that these hormones do not exert any influence on their reproductive potentials. This along with earlier observations show that the factors which regulate ovarian maturation and fecundity in these rat fleas are different from those of the rabbit flea Spilopsyllus cuniculi (Dale).

Animals↗
PubMed1976

Studies on the host-flea relationship. III Nutritional efficacy of blood meal of rat fleas Xenopsylla cheopis (Rothschild) and Xenopsylla astia (Rothschild).

Rat fleas, Xenopsylla cheopis (Rothschild) and X. astia (Rothschild) were fed artificially on whole blood, milk and blood fractions in an attempt to identify the factor(s) which trigger ovarian maturation. Blood from the white rat, house rat, white mouse, frog, chick and man fed artificially induced vitellogenesis in over 50% of fleas of all combinations except in X. cheopis fed on chick blood. Gut distension alone had no influence on initiation of vitellogenesis as judged by feeding milk. Washed white rat blood cells resuspended in saline initiated vitellogenesis, but plasma did not. Addition to plasma of ATP, glutathione and serotonin did not initiate yolk deposition. However, raising the protein concentration of the rat plasma had a decided influence on vitellogenesis. The protein concentration of the diet appeared to be a decisive factor in initiating yolk deposition in these fleas. A change from whole blood to plasma diet caused all the mature oocytes to resorb in both the species of fleas.

Animals↗