Abstract
Analysis of urinary metabolites of [1, 2-3H]-3α, 5β-tetrahydroaldosterone was performed in male guinea-pigs. Separation of urinary metabolites was carried out by means of DEAE-Sephadex A-25 column chromatography and four fractions (fraction A to fraction D) Were detected. 46-50% of fraction A was extractable with ethyl acetate. When ethyl acetate extract was submitted to reversed phase high pressure liquid chromatography, a number of peaks were present and one of these peaks cochromatographed with 3α, 5β-tetrahydroaldosterone. Fraction B, fraction C and fraction D were incubated with enzyme and the free steroid released was identified on the basis of retention time on reversed phase high pressure liquid chromatography. Thus, fraction B contained monoglucosiduronate of 3α, 5β-tetrahydroaldosterone, whereas identification of fraction C was not successful. Fraction D was characterized as a monosulphate 3α, 5β-tetrahydroaldosterone, 3α, 5β-tetrahydroaldosterone and 3β, 5α-tetrahydroaldosterone were identified as aglycones.
It is probable that 3β, 5α-tetrahydroaldosterone is converted from other tetrahydroisomers by intestinal bacteria of the guinea-pig, since mammalian tissues do not contain enzymes that introduce a double bond into ring A.
