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Thyroidectomy and orchidectomy led to significant reduction in the oxidative metabolism of isolated liver and skeletal muscle tissue (at 30 °C) in Calotes versicolor. Thyroxine and male hormone were shown to increase this parameter in intact and orchidectomized lizards respectively. The effects of thyroidectomy and orchidectomy on tissue oxygen uptake were not additive. It is supposed that by its effect on oxidative metabolism male hormone may be of a greater physiological importance for reptiles than for other vertebrates.The present results show also that changes in environmental temperature can counteract the depressive effect of orchidectomy on the thyroid of this species of lizard.

Orchidectomy in Hemidactylus flaviviridisled to significant reduction of thyroidal 131I uptake, thyroidal content of thyroxine, plasma protein-bound iodine and oxygen consumption of isolated liver and skeletal muscle (at 30 °C). Administration of testosterone to orchidectomized lizards restored these parameters to normal levels. Dependence of thyroid function and oxidative metabolism on male hormone may be a general feature in reptiles. This hormone may, therefore, be of greater physiological importance in these animals than in other vertebrates. Since reptiles occupy a crucial phylogenetic position in the animal kingdom these findings are important from the point of view of evolution of the functional aspects of hormones in vertebrates.The results also show that thyroid function is inhibited by oestrogen(s) in this lizard. This may be an adaptive compensatory measure to control (through effects of the thyroid on metabolic activities) the extra expenditure of energy usually associated with such energy-consuming functions as ovulation and egg-laying.

1.1. Using gas-liquid phase chromatography, a technique has been developed for measuring tissue progesterone levels.2.2. Because this procedure requires fewer preliminary steps in purification and extraction, the placental levels found have been approximately twice those previously reported, and human myometrium from the term or near-term pregnant uterus has been found to have a concentration of progesterone varying from 0.05 to 0.63 μg per gram wet weight tissue.

Aldosterone has been injected subcutaneously into young rats in doses of 0.5 μg. per 48 hours and later 1.0 μg. per 24 hours. After 6–12 weeks a rise in blood pressure was noted which in about 5 or 6 months reached a maximum averaging 75 mm. above control values. This effect was noted in intact animals on a normal diet and was the same for either dose employed. The drinking of 1% saline instead of water had no significant effect on the result. In adrenalectomized rats a similar rise was noted and may have occurred sooner, but this observation requires confirmation. Aldosterone can account for at least part of the syndrome resulting from regeneration of cortical tissue in an enucleated adrenal. Desoxycorticosterone was tested in intact rats at dose levels of 25 μg. per 48 hours or 100 μg. daily and produced a smaller rise in blood pressure than that observed with aldosterone. None of the adrenalectomized rats showed protein in the urine, but one in five of the intact animals developed moderate to marked proteinuria after 1 to 5 months of hypertension. It is suggested that these observations may represent the experimental counterpart of human essential hypertension.

Tissue electrolyte levels were determined in human myometrium, and the placental site compared with the antiplacental. Differences in the sodium, potassium, chloride, and calcium contents were noted between these two areas, a difference with respect to each ion which shifted with the dura tion of pregnancy.

The effect of progesterone on potassium fluxes in human myometrium has been evaluated. In vitro preparations revealed that progesterone decreased both influx and efflux through myometrial cell membrane.

1.1. Using an intracellular microelectrode technique, the effect of progesterone on human myometrium was evaluated.2.2. In vitro preparations revealed that one of the mechanisms by which progesterone exerts its effect in relaxing the human myometrium is by hyperpolarizing the membrane.

The high energy phosphate compounds ATP, PC, and ATP plus PC have been studied in pregnant and nonpregnant human myometrium. An attempt has been made to correlate the distribution of these compounds with the contractile patterns of the uterus.