The secretion of pepsin.

1. Ligation and division of the vessels supplying the stomach, except those from the spleen, result in greatly increased pepsin secretion in response to pentagastrin, pilocarpine or 2-deoxy-D-glucose. 2. This effect was still present 6 months after initial ligation. 3. Analysis of dose-response curves shows that for pepsin secretion the Vmax values were raised by this procedure. 4. Right-sided vessel ligation and division does not alter acid secretion in response to the stimuli used. 5. It is suspected that the procedure of right-sided vessel ligation removes a non-competitive inhibitor mechanism to gastric pepsin secretion.