Urinary Steroids of Cats

Adrenal steroid secretion by cats has been studied by Bush (1951, 1953) and reviewed by Dorfman (1959). The cat adrenal secretes both cortisol and corticosterone. Arteta & Borrell (1958) and Borrell (1958) have reported studies of urinary excretion of 17-hydroxy corticosteroids (PorterSilber chromogens). Cats appear to excrete in urine very low concentrations of 17-hydroxy corticosteroids, all as free steroid. It was possible to demonstrate an increase after the administration of adrenocorticotrophic hormone (ACTH) (Borrell, 1958). Taylor & Scratcherd (1960, 1962) have obtained evidence that the major pathway for excretion of metabolites of progesterone and corticosterone is via the bile and the faeces. Borrell (1963) has shown that there is essentially no 17-oxo steroid in cat urine. In the present paper, the results ofan investigation into the substances reducing blue tetrazolium (blue tetrazolium chromogens) of cat urine are reported. Steroids among these reducing substances would include the 17-hydroxy corticosteroids, the oc-ketolic C21 steroids and oc,f-unsaturated ketones such as A4-3-oxo steroids.