The contribution of the adrenal gland to the total amount of progesterone produced in the female rat

Abstract

SUMMARY1. The amount of progesterone contained in both adrenal glands of a rat was similar to or larger than the amount of progesterone in the ovaries of the same rat. This was found in unstressed rats, in stressed rats and also in pregnant rats.2. After ether anaesthesia and exsanguination the adrenal progesterone content was increased by 75 %; the ovarian progesterone content re-

Variation in Activity of Monoamine Metabolizing Enzymes in Rat Liver During Pregnancy

“…The naturally occurring changes in progesterone concentrations during the oestrous cycle are sufficiently large to influence MAO activity in various tissues including brain (Kamberi & Kobayashi, 1970;Holzbauer & Youdim, 1972;Youdim, Holzbauer & Woods, 1974). Some measure of the connection between MAO activity and progesterone production was provided by Holzbauer & Youdim (1973) who measured the progesterone content of ovaries and adrenal glands which synthesize and secrete about equal amounts of progesterone in the rat (Fajer, Holzbauer & Newport, 1971;Holzbauer & Godden, 1974 (Milkovic, Milkovic & Paunovic, 1973;Challis, Heap & Illingworth, 1973) also tend to agree with the present results. Urinary output, and release into the blood steam of both adrenaline and noradrenaline is persistently increased during the last days of pregnancy (Parvez et al, 1973a and b).…”

Atrazine-induced elevation or attenuation of the LH surge in the ovariectomized, estrogen-primed female rat: role of adrenal progesterone

“…Adrenal secretion occurs in concentrations that are typically comparable to ovarian release (Fajer et al 1971, Shaikh & Shaikh 1975. There is also evidence that local P 4 synthesis is present in hypothalamic astrocytes and has been shown to occur in response to estrogen feedback (Micevych et al 2003), linking this effect to generation of the LH surge.…”

Rate of ovarian progesterone secretion and peripheral plasma progesterone levels in unilaterally ovariectomized, pregnant rats

“…number of live fetuses in the uterine horn used for blood collection was similar in the control and unilaterally ovariectomized rats (4-9 ± 0-6 and 4-4 ± 0-7, respectively) as too were arterial pressure (130 ± 4 and 125 + 5 mmHg) and haematocrit (42-3 ± 0-6 and 42-3 ± 1-1%). (Heap et al, 1966;Fajer et al, 1971;Ogle & Kitay, 1977). Since an initial transitory rise in plasma progesterone levels was not observed in the unilaterally ovariectomized rats, it is possible that total ovarian progesterone secretion was, at least temporarily, reduced by the operation but that this effect was balanced by an increase in secretion from the adrenals.…”

“…This suggests that the rate of progesterone secretion by the corpora lutea (CL) in the remaining ovary of unilaterally ovariectomized rats is substantially increased with little, if any, increase in tissue mass. Alternatively, plasma progesterone levels may be maintained by increased progesterone secretion from the adrenals (Heap, Holzbauer & Newport, 1966;Fajer, Holzbauer & Newport, 1971;Ogle & Kitay, 1977) or placentas, or by a reduction in the metabolic clearance rate of progesterone.…”