Renin-like (angiotensinogenase) activity in sweat of patients with cystic fibrosis and controls.

Using bioassay method (rat blood pressure technique) as well as the radioimmunoassay, 
renin-like activity (RLA) was measured in eccrine sweat of patients with 
cystic fibrosis of the pancreas (CF) and of controls. Sweat-formation was 
induced by pilocarpine-iontophoresis or by local injection of carbamylcholine (Doryl). RLA-values 
between O (not measurable) and 460 ng/ml.h were measured. With increasing 
sweat flow-rate a tendency to lower RLA-values was detected. No significant 
difference was observed between CF and controls. From the observation that 
RLA of sweat is up to 30 times higher than that 
of plasma, it is concluded that RLA is probably released not 
from plasma but from the sweat glands themselves, where it is 
stored or synthesized. 