Effect of castration and of male hormone administration on the tissue respiration and thyroid activity of the checkered water snake, Natrix piscator

Influence of thyroid hormones and testosterone on the activities of hepatic mitochondrial enzymes in the Indian garden lizard, Calotes versicolor

Thyroidectomy and castration in Calotes versicolor significantly decreased the activities of hepatic mitochondrial cytochrome oxidase, alpha-glycerophosphate dehydrogenase (alpha-GPDH), and succinate dehydrogenase (SDH) when compared to sham-operated controls. Administration of thyroid hormones in thyroidectomized lizards and testosterone in castrated specimens stimulated the activities of all three enzymes studied. Chloramphenicol, when injected with thyroxine prevented the hormone-stimulated activities of cytochrome oxidase and SDH, while actinomycin D and chloramphenicol, when administered along with testosterone propionate (low dose) prevented the testosterone-stimulated activities of cytochrome oxidase and alpha-GPDH.

Role of thyroid in tissue respiration of birds

Thyroidectomy after 1 week, 1 month, and 13 months significantly depressed and low level of L-T4 significantly elevated the oxygen uptake of the liver and skeletal muscle of spotted munia and common myna. A higher dose of L-T4 had no effect on the rate of respiration. A reexamination of the published results on submammalian vertebrates together with those presented here suggests that an uniform pattern of response of skeletal muscle emerges if the values from thyroidectomized animals are compared not only with the final controls but also with the initial controls. It is, therefore, suggested that all the earlier works be reexamined and reinterpreted.

Influence of oestradiol on tissue respiration of the Indian garden lizard, Calotes versicolor

Ovariectomy reduced the respiratory rates of liver and skeletal muscle homogenates of the Indian garden lizard, Calotes versicolor. Administration of oestradiol dipropionate elevated the rate of tissue respiration of ovariectomized animals. This finding lends support to the view that oestradiol, like testosterone, is able to stimulate the oxidative metabolism of this animal.