Pharmacological activities of t-amyloxy-carbonyl tryptophanyl-methionyl-asparatyl-phenylalanine amide.

polypeptides containing 17 amino acids and their structures were subsequently confirmed by total synthesis by Anderson et al. (3). During the studies on synthetic polypeptides structurally related to gastrin, Tracy and Gregory (4) discovered that the C-terminal tetrapeptide, Try. Met. Asp. Phe. NH,, could show the full range of physiological actions of natural porcine gastrin, even though it was quantitatively less active. The gastric secretory actions of gastrin-like peptides have been investigated in anesthetized rats by Barrett (5), and Barrett et al. (6), in conscious or anesthetized dogs by Morley et al. (7), Konturek and Grossman (8), on the isolated gastric mucosa of the bullfrog by Davidson et al. (9), and in clinical investigations by Wormsley et al. (10), Makhlouf et al. (11), Konturek (12) and Fitzgerald (13). They described that gastrin-like peptides were the specific gastric secretory stimulants which possessed the properties necessary to replace histamine in assessing the maximal acid response of patients and were usefull as the new tool for research in gastric secretion. Recently, we gained a new acylated derivative of tetrapeptide amide , t-amyloxycar bonyl Try. Met. Asp. Phe. NH2 (114). The present study is concerned in the com parison of this tetrapeptide with other secretagogues such as other gastrin-like peptides, histamine, bethanechol etc. using various preparations of rats and in other pharmacologi cal studies of several gastrin-like peptides.