Adrenal Secretion Rates of C-19 and C-21 Steroids Before and After Hypophysectomy in the Pig and the Dog

Abstract

1) The adrenal secretion of androgens and of some intermediates of corticosteroid biosynthesis have been studied in immature pigs and adult dogs under anaesthesia.(2) Qualitative and quantitative analyses of the extracts of adrenal venous blood were performed by a combination of paper and gas chromatographic techniques.(3) In both species 1 1\g=b\OH-androstenedione,pregnenolone, progesterone and 1 1\g=b\OH-progesterone were secreted under stress conditions at a mean rate of approximately 20 \g=m\g./adrenal/hr.; this was somewhat more than aldosterone secretion and about one-fiftieth of the glucocorticoid secretion.(4) Within 2 hr. of hypophysectomy the secretion of all four compounds was decreased by more than 95%.

Plasma Progesterone Levels in Pregnant and Pseudopregnant Ferrets

“…Corpora lutea were dissected from the ovaries of pregnant and pseudopregnant females, stored in A.R. absolute alcohol at -20°C, and the steroids were extracted and assayed by gas chroma¬ tography (Heap, Holzbauer & Newport, 1966) and fluorimetry (Heap, 1964 Progesterone was not detectable by radioimmunoassay in plasma samples taken from females in oestrus, or after parturition, or from male ferrets.…”

Glycol metabolites of noradrenaline in brain tissue

“…Quantitative estimation of MOPEG and DOPEG The principle of the method has been described for the estimation of steroid compounds by Vandenheuvel, Hinderks, Nixon & Layng (1965), Wisniewski & Umbreit (1965) and by Heap, Holzbauer & Newport (1966); it is based on the ratio of the sizes of the responses of two substances, a and b which have different retention times. If the ratio of the sizes of the two responses is proportional to their relative concentrations in a mixture of the two substances and the total amount present in the sample of one of them is known, then the total amount of the other substance present in the sample can be calculated from the equation…”

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.…”