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Biomedical subjects

S Rani

Publications and source records attributed to S Rani.

83 records · Page 5Linked to original sources
PubMedDate not supplied

The influence of light wavelength on reproductive photorefractoriness in migratory blackheaded bunting (Emberiza melanocephala).

There are two effects of long day length on reproductive responses in birds, one is the photoinduction of gonadal growth and maturation and the other is the induction of gonadal regression and photorefractoriness. Although it is likely that the same photoreceptors are involved in the photoinduction of gonadal growth and the onset and maintenance of photorefractoriness. and so the influence of wavelength should be similar, this has not been investigated. Therefore, we investigated the influence of light wavelength on reproductive photorefractoriness in the migratory male blackheaded bunting held under long photoperiods. In mid May, when photoperiod was approximately 14L:10D (14 hours light:10 hours darkness), eight groups of sexually mature birds were moved indoors on an artificial photoperiod of 14L:10D (L - 450 lux. D - 0 lux). Then after 3 weeks, for six groups, a 4-h light period in the morning (zt 0-4; zt 0 [zeitgeber time 0] refers to the beginning of lights-on period) or in the evening (zt 10-14) was substituted with green (428 nm), red (654 nm) or white light at 16 +/- 2 lux intensity. Of the remaining two groups, one was maintained on 14L: 10D and the other transferred to 10L:14D: these served as controls. At the end of 4 weeks, all birds were found to have undergone testicular regression, irrespective of LD cycle they were exposed to. When these gonadally regressed birds were subjected to 16L:8D for another 4 weeks, to test their responsiveness to the stimulatory effects of long day lengths, only those exposed to 10L:14D and 14L:10D with a 4-h green light period showed testicular regrowth. On the other hand, birds exposed to 14L:10D with a 4-h white or red light period remained fully regressed, similar to 14L:10D controls. Except for some individual difference, there was no difference in response between the groups that received a 4-h light period in the morning and that received it in the evening. These results suggest that the wavelengths of light influence induction of buntings from the photosensitive state into the photorefractory state. Whereas the short light wavelengths facilitated recovery from the photorefractoriness, the long light wavelengths were more effective in maintaining the photorefractoriness.

Animals↗
PubMedDate not supplied

Effect of Glyzophrol on fertility of female black rats (Rattus rattus).

Mild degree of fibrosis, dilatation of blood vessels, haemorrhagic reactions in a few places, granulosa cells in stroma and no effect on maturation process of follicles were observed in ovary of 20 mg/kg of Glyzophrol treated rats. After 60 mg/kg of Glyzophrol treatment, ovary revealed reduction in number of follicles, degenerative changes in existing follicles, frequent proliferation of granulosa cells and fibrosis in stroma along with karyorrhexis, karyolysis and pyknosis in nuclei. Haemorrhage and dilated blood vessels in stroma were well marked, suggesting that ovarian vasculature was affected by glyzophrol. Ovary exhibited increase in activity of acid phosphatase after Glyzophrol treatment. Intense alkaline phosphatase activity was observed in entire ovarian tissue after Glyzophrol treatment.

Acid Phosphatase↗
PubMedDate not supplied

Effect of glyzophrol on fertility of female black rats (Rattus rattus).

A mild degree of fibrosis, dilatation of blood vessels, haemorrhagic reactions in a few places, granulosa cells in the stroma and no effect on the maturation process of follicles were observed in the ovaries of 20 mg/kg of Glyzophrol treated rats. After 60 mg/kg of Glyzophrol treatment, the ovary revealed a reduction in the number of follicles, degenerative changes in existing follicles, frequent proliferation of granulosa cells and fibrosis in the stroma, along with karyorrhexis, karyolysis and pyknosis in the nuclei. Haemorrhage and dilated blood vessels in the stroma were well marked, suggesting that ovarian vasculature was affected by Glyzophrol. The ovary exhibited an increase in the activity of acid phosphatase after Glyzophrol treatment. Intense alkaline phosphatase activity was observed in the entire ovarian tissue after Glyzophrol treatment.

Acid Phosphatase↗