Diurnal progesterone rhythms in the female mouse

ABSTRACT The patterns of peripheral progesterone concentrations were investigated in a number of murine models on a 13 h light: 11 h darkness lighting regime. The pattern in the intact mouse at dioestrus was compared with that in the ovariectomized mouse. A diurnal pattern was recorded in both, maxima occurring around the end of the light period; no conspicuous nadir was recorded, levels of progesterone remaining relatively constant over a 14-h period. Adrenalectomized mice displayed no such rhythm, indicating that the adrenal is responsible for any diurnal rhythm in peripheral plasma progesterone concentrations at dioestrus. At pro-oestrus in intact animals a similar rhythm was observed, but the maximum levels of progesterone were approximately five times greater than at dioestrus and, moreover, persisted in adrenalectomized mice, indicating that the rhythm of adrenal secretion of progesterone is masked by ovarian secretion. Ovariectomized mice with implants of oestradiol-17β displayed a similar rhythm to that of intact mice at dioestrus, but had significantly higher plasma progesterone levels around the time of the maxima although not over the total 24-h period. An s.c. injection of oestradiol benzoate superimposed on oestrogen levels produced by implants had no significant effect on plasma progesterone levels. Also at pro-oestrus the pattern of peripheral LH concentration was investigated in both the intact and the adrenalectomized mouse. For both, maxima were recorded just before darkness, at 19.00 h, in advance of the progesterone surge. In adrenalectomized mice this surge at 19.00 h was attenuated. The possible role of adrenal progesterone in ovulation and the mechanisms by which endogenous oestrogens might enhance adrenal progesterone output are considered. J. Endocr. (1987) 112, 15–21

BIOLOGICAL ACTIVITY OF CORTICOSTERONE AND 11-DEOXY-CORTICOSTERONE C-21 ESTER SULFATES COMPARED WITH THAT OF THE CORRESPONDING STEROID-FREE ALCOHOLS

Corticosterone-21-suifate was assayed for liver-glycogen deposition in the adrenalectomized mouse, and 11-deoxycorticosterone-21-sulfate for mineralocorticoid activity (urinary sodium/potassium) in the adrenalectomized rat. Compared with equimolar doses of corticosterone (140–870 mμmoles/mouse) and of 11-deoxycorticosterone (4.5–36.0 mμmoles/rat) the two conjugates were devoid of biological activity.

Role of the adrenal in ethionine mobilization of fat

We have shown that ethionine increases the liver lipid in normal fasted mice but this effect is not accentuated by epinephrine. Likewise ethionine increases lipid in the liver of fasted mice with demedullated adrenals while epinephrine produces no significant increase. In the adrenalectomized mouse epinephrine did augment deposition of lipid in the liver when combined with an amount of cortisone too small to be effective per se. A somewhat larger dose of cortisone was just as effective as these two substances combined. Still greater amounts failed to increase the effect. A dose of adrenal extract sufficient to maintain normal behavior and a satisfactory weight gain, proved inadequate for the normal response to ethionine probably due to the absence of an essential hormone. However it was as effective as any dose of cortisone.