ARGININE INFUSION INCREASES PERIPHERAL PLASMA SOMATOSTATIN IN MAN

Publisher Website
Google Scholar
Abstract
A somatostatin (SRIF) radioimmunoassay is described, using an antiserum raised in rabbit, reacting more with SRIF-14 than -28. Glass tubes were employed for the assay because the tracer, 125I 1-Tyr-SRIF, was adsorbed to plastic (23% non specific binding). Vycor extraction was used, and following Sephadex G-50 chromatography, the plasma extract showed 2 forms, coeluting with SRIF-28 and-14. Fifteen healthy subjects, 8 women and 7 men, 21-39 yr old, received an infusion of arginine chloride (2.38 mmol/kg) for 20 min, or saline. An immediate rise in plasma SRIF from the mean basal level at 2 min was shown. Maximal value was 24.0 .+-. 3.0 pmol/l (P < 0.01) after 10 min followed by a rapid descent towards the basal level after the infusion. A temporal relationship was observed between the SRIF, insulin and glucagon responses following arginine infusion, while the GH [growth hormone] levels increased only after the SRIF levels had declined, indicating an inhibition of GH. This is further supported by the high degree of correlation (r = 0.87) between SRIF- and GH increments. Plasma SRIF measurement during arginine infusion could give an estimate of the pancreatic SRIF releasing capacity.