Occurrence of 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-β-carboline in tissues and body fluids of rat

Abstract

A capillary column gas chromatographic-mass spectrometric method was used to identify and quantitate 6-hydroxy-1-methyl-1, 2, 3, 4-tetrahydro-β-carboline (6OMTHBC) in rat. The excretion rate in urine was 0.73 ± 0.20 nmoles per 24 hr and in faeces 0.18 ± 0.03 nmoles per 24 hr. In urine, about 90% of the 6OMTHBC was in a conjugated form, whereas in faeces most (∼ 75%) of the 6OMTHBC was in a free form. The compound was detectable in liver (11.1 ± 3.6 pmoles/g), kidney (2.1 ± 0.9 pmoles/g) and plasma (0.52 ± 0.15 pmoles/ml), but not in brain (<0.3 pmoles/g). When 6OMTHBC was injected to rats, 75% of the injected amount was excreted in urine during the first 10 hr. The plasma level of 6OMTHBC declined with a half-life of 1.5 hr.