Corticosteroid Secretion in Kangaroos (Macropus Canguru Major and M. (Megaleia) Rufus)

Abstract

Adrenal venous and peripheral blood was collected from five adult and two immature kangaroos, anaesthetized with pentobarbitone.Seven C-21 \ g=D\ 4, 3-oxo steroids were identified in extracts of adrenal venous blood from all animals. The major component\p=m-\72\p=n-\92% of detected corticosteroids\p=m-\was cortisol. The remainder were 11 -deoxy and 21 -deoxy cortisol, corticosterone, aldosterone, 11\g=b\-OH and 17\g=a\-OH progesterone. In four out of six experiments, i.v. corticotrophin caused variable degrees of increase in corticosteroid secretion. Maximum cortisol secretion rates in all the adults and the immature male were in the range 29\p=n-\70\g=m\g./hr./100mg. adrenal, or 28\p=n-\58 \ g=m\ g. / hr. / kg. body weight and 98 \g=m\g./hr./100mg. or 114 \g=m\g./hr./kg. in the immature female.Average aldosterone secretion rate in the adults was 0\m=.\27 \g=m\g./hr./100mg. adrenal, or 0\m=.\18\g=m\g./hr./kg.body weight. It was significantly higher in the immature male. However, the Na status of the animals was not known.Cortisol was the major corticosteroid in peripheral blood plasma at concentrations of 2\ m=. \ 0\ p=n-\ 8\ m=. \ 1 \g=m\g./100 ml.The unusual secretion of 21-deoxy cortisol suggests there may be differences in some aspects of adrenocortical biosynthesis, compared with eutherians.

Adrenal Steroid Secretion in the Koala (Phascolarctos Cinereus)

“…The presence of 21-deoxy cortisol is unusual, but is in keeping with the earlier findings in the possum and kangaroo (Weiss & McDonald, 1967;Weiss, 1968) and more recently in two carnivorous marsupials (to be published). Aldosterone secretion is in the range found in other marsupials and that of eutherian mammals.…”

“…The adrenal venous collections were made as previously reported (Weiss & McDonald, 1965). Procedures for isolation, characterization and quantitative assay of steroids are described in previous publications (Weiss & McDonald, 1967;Weiss, 1968). Additional procedures employed were: (1) thin-layer chromatography on silica gel G (Stahl) in systems chloroform:ethyl acetate (1:50), chloroform: n-hexane (1: 10); (2) gas chromatography of 17 keto-and 21 deoxy-steroids using a model 402 F and M instrument with a glass column and 5 % SE-30 packing, temp.…”

Adrenal Steroid Secretion in the Tasmanian Devil (Sarcophilus Harisii) and the Eastern Native Cat (Dasyurus Viverrinus). A Comparison of Adrenocortical Activity of Different Australian Marsupials

“…The criteria by which cortisol, 11-deoxycortisol, corticosterone, 21-deoxycortisol and 11/?-and 17 -progesterone were identified were those previously described (Weiss & McDonald, 1967). As a further demonstration of the identity of 21-deoxycortisol isolated from pooled extracts of adrenal venous blood of devils, an infrared spectrum was recorded (Fig.…”

“…We previously reported the isolation of 21-deoxycortisol from the adrenal venous blood of the possum and kangaroo (Weiss, 1968;Weiss & McDonald, 1967) and recently in the koala (Weiss & Richards, 1970). It would seem not un¬ reasonable to postulate, as have Finkelstein et al, that this type of secretion can be attributed to the persistence of a primitive or immature enzyme system (Finkelstein, Shoenberger, Maschler & Halperin, 1967).…”

“…The procedures for isolation, characterization and quantitative assay of steroids have been described previously (Weiss & McDonald, 1967;Weiss, 1968). Additional procedures employed were chromatography on silica gel 'G' (Stahl) thin layers (TLC) in the following systems: chloroform : ethyl acetate (1:50, v/v), dichloro¬ methane : methanol : water (150:9:0-5, by vol.…”