The effect of indoramin on peripheral blood flow.

1 The effect of indoramin, a new hypotensive agent, on peripheral blood flows of six normal subjects was determined and compared to placebo in a double-blind, randomized study. 2 Indoramin (0.25 mg/kg), administered intravenously, resulted in an increased forearm muscle volume as measured by strain gauge plethysmography and an increase in the skin temperature of the hand but not to the skin of the chest. 3 It is concluded that these effects are the result of α-adrenoceptor blockade.

Evaluation of succinimidoethyl and pivaloyloxyethyl esters as progenitors of methyldopa in man, rhesus monkey, dog, and rat.

The succinimidoethyl (Sm) and pivaloyloxyethyl (P) esters of methyldopa were evaluated as progenitors of the latter. Experiments in spontaneously hypertensive (SH) rats and humans demonstrated that a radioactive dose of progenitor was well absorbed. The metabolism of these progenitors appeared to be comparable in the SH rat; the urinary excretion of [3H]methyldopa was similar after oral administration of [3H]Sm or [3H]P. In humans the levels of [3H]methyldopa were higher in the urine following administration of [3H]P. Apparently Sm was more resistant than P to extrahepatic esterase action in man (and dog). In man the catechol nucleus of Sm was apparently conjugated prior to hydrolytic cleavage to release conjugated [3H]methyidopa. The progenitors possessed similar antihypertensive properties in the SH rat but preliminary results in humans suggested that Sm possessed less antihypertensive potency than P.