Renin-like (angiotensinogenase) activity in human eccrine sweat

The presence of renin or renin-like activity (RLA) was demonstrated in human eccrine sweat incubated with purified sheep angiotensinogen, using rat bioassay and angiotensin I radioimmunoassay. Following cholinergic stimulation, sweat RLA was found to range between 0 (unmeasurable) and 266 ng/ml.h, i.e. RLA-values of sweat can be about 10 times higher than those of plasma. Therefore, renin synthesis in sweat glands could be assumed. RLA following activation of beta-adrenergic receptors by the administration of isoprenaline (Aludrin) did not exceed the mean values obtained by cholinergic activation. After beta-adrenergic receptor blockade by propranolol (Dociton), RLA became unmeasurably low. Higher RLA-values were found after local injection of dibutyryl-c-AMP (90--210 ng/ml.h). The results indicate a beta-adrenergic regulation of RLA-release in human sweat glands. Human sweat glands appear to be useful for studying extrarenal renin release.