Showing papers on "Bufo melanostictus published in 1985"

Effect of hypobaric hypoxia on spermatogenesis, Leydig cells and delta 5-3 beta-hydroxysteroid dehydrogenase activity in toad.

Abstract: The effect of different grades of hypobaric hypoxia for 48 hours was studied on spermatogenesis, Leydig cells and delta 5-3 beta-hydroxysteroid dehydrogenase activity in toad (Bufo melanostictus). Maximum inhibition of testicular activity was noted in 7,315 m exposed animals. The impairment of testicular function at high altitude is possibly due to inhibition of gonadotrophin secretion.

Effect of thyroxine on hepatic glucose-6-phosphatase activity and glycogen content of toad (Bufo melanostictus) and Lata fish (Ophicephalus punctatus) at different stages of life.

Abstract: The effects of thyroxine (T4) on hepatic glucose-6-phosphatase activity and glycogen content in toad (Bufo melanostictus) and Lata fish (Ophicephalus punctatus) were studied in order to show the difference, if any in the enzyme activity and glycogen metabolism in their liver. Thyroxine injections (1 microgram/g) for five consecutive days caused a reduction in hepatic glucose-6-phosphatase activity and glycogen content in toads of immature, juvenile and adult stages. In contrast, Lata fish of different stages showed an enhancement of hepatic glucose-6-phosphatase activity after T4 treatment (1 microgram/g, 5 injections). The liver glycogen content in Lata fish of different age groups was found to be reduced after T4 injections, but not so much as in the toad.

Studies on some enzymes of the toad (Bufo melanostictus) testis and their probable role at the time of fertilization

Abstract: Glycosidases like sialidase,β-galactosidase, α-L-fucosidase, N-acetyl hexosaminidase and proteases were detected in toad testis. Neuraminic acid aldolase activity was also detected. The enzyme activities were found to vary as production of spermatozoa varied. All enzymes, except N-acetyl glucosaminidase, were shown to decrease after injection of toad pituitary extract and they were also found to be absent from testis containing no spermatozoa. The glycosidases were found to act on toad oviduct jelly and they may therefore be involved in the degradation of the jelly after fertilization, into smaller bits, which may be utilized as nutrients by the fertilized zygote.