Inhibition by hexoestrol of adrenocortical secretion in the rat

Abstract

It has been known for a long time (Korenchevsky & Dennison, 1935; Selye, Collp & Thomsen, 1935) that oestrogens cause hypertrophy and hyperplasia of the rat adrenal cortex. Selye & Collip (1936) have shown that this effect is absent in the hypophysectomized rat, even when the adrenal cortex is maintained by adrenocorticotrophic hormone (ACTH). The inference is that oestrogens cause an increase in secretion of ACTH and thus produce adrenal hypertrophy indirectly. During hexoestrol administration the pituitary hypertrophies and goes on growing for at least 6 weeks (Somers, 1948). Gemzell (1952) was able to demonstrate an increase in the amount of circulating ACTH in rats injected with oestradiol. The release of ACTH by oestrogens is considered to be an example of an unspecific response to stress (Tepperman, Engel & Long, 1943). Loeser (1939) observed the disappearance of lipids from the adrenals of rats injected with stilboestrol. A detailed examination of the effect of hexoestrol (Vogt, 1945) showed that sudanophilic lipids disappeared almost completely from the zonae fasciculata and reticularis in the course of 5 days, and from all three layers if the treatment lasted 10 days or more. These effects, too, were absent in hypophysectomized rats not given ACTH: experiments with ACTHmaintained rats were not performed.The functional state of lipid-depleted adrenals has been a matter of conjecture. Many histologists consider them to be hyperactive glands (Dosne & Dalton, 1941;Sarason, 1943), whereas others (Zwemer, 1936;Deane & McKibbin, 1946; Flexner & Groilman, 1939) suggest that they are in a state of exhaustion following initial hyperactivity. Both these interpretations are prompted by the observation that the early response to any stress or to an injection of ACTH is a diminution of adrenal lipids, more especially of cholesterol esters. However, this diminution is followed by recovery to normal or even by deposition of abnormally high amounts of lipids whenever treatment

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

“…The blood lost was replaced by an infusion of arterial blood from male rats or of a 0-9 % sodium chloride solution. The body temperature was maintained between 36 8 and 380 C. Adrenal venous blood was collected in a similar manner, the ovarian vein being ligated instead of the adrenal vein (Vogt, 1955). The adrenal glands and the ovaries were dissected out immediately at the end of the blood collections and frozen.…”

“…Corticosterone was eluted from the E2B chromatogram and estimated by its reaction with blue tetrazolium (Vogt, 1955;Holzbauer, 1964). The values given for progesterone and 20-dihydroprogesterone were corrected for losses.…”

Adrenocortical secretion in the guinea‐pig

“…Cortisol secretion in guinea-pigs of different sizes In young animals of about 500 g body weight cortisol was secreted at a mean rate of 94 ,ug/g adrenal/min (Table 2); under comparable conditions rat adrenals secrete corticosterone 20-29 ,ug/g/min (Vogt, 1955;Holzbauer & Vogt, 1957); for both species the methods of estimation used were the same and the figures were not corrected for losses during extraction. 10-8 200 -250 6-5 9 440 106 240 9-3 134 140 4-5 10 470 107 227 11-2 153 70 4-8 11 475 130 273 10-3 168 -80 4-6 12 440 126 286 10-2 175 50 3-8 Mean+s.E.…”

The actions of ethinyloestradiol on the pituitary‐adrenal system of the rat

“…There have been many reports demonstrating that oestrogens can inhibit corticosterone secretion, and in most cases the experimental procedures applied were known to cause near maximal secretion of ACTH (Vogt, 1955;Holzbauer, 1957b;Holzbauer & Vogt, 1957a ;Kitay, 1963b;Saba & Hoet, 1963 ;Pincus & Hirai, 1964).…”