Renal excretion of and the effect of posture on serum group I pepsinogens.

Serum group I pepsinogens (PG I) were determined by a radioimmunoassay method in blood drawn from the right femoral vein, the right renal vein, the liver vein, the right atrium, and the left femoral artery from 10 patients undergoing cardiac catheterization. Clinically they had no cardiac insufficiency, and their renal function was normal. The serum PG I concentration was similar in the femoral artery and vein and in the right atrium. On the other hand, serum PG I was higher in the liver vein and lower in the renal vein than in the other sampling sites. The renal arteriovenous serum PG I difference was positively correlated to the arterial concentration. The influence of posture on serum PG I was studied in another nine healthy subjects. Serum PG I was lower in the supine position than in the erect position.