Abstract
The plasma 3H-radioactivity level showed a high value 1 hr after intraperitoneal injection of 3H-metaproterenol and it lowered lineraly to reach 40% of the peak level 5 hr after administration. Radioactivity distributed to the kidneys and liver was markedly higher than that in other organs. Forty per cent of the amount given orally was excreted in the 24 hr urine specimen. The major part of metaproterenol was excreted in urine as an unchanged compound in the early stages after administration and the remainder in the form of glucuronide in the late stages. It is concluded that the absorbed metaproterenol remains unmetabolized for a considerable length of time in the body and high plasma levels are maintained for a relatively long period.
