Add time:08/21/2019         Source:sciencedirect.com

Four dogs with chronic gastric fistulas were given intravenous bombesin nonapeptide (B9), ranatensin, and litorin by constant infusion for 90 min at 1.2 μg·kg−1·h−1 on separate days. A dose response study with substance P (1.5, 3.0, 60, 18 and 54 μg·kg−1·ht-1 was also carried out and all tests compared to a standard protein meal (10 μg·kg−1. Plasma gastrin and PP were measured by radioimmunoassay and gastric acid by autobiuret titration. Substance P failed to stimulate gastric acid secretion or release either pancreatic polypeptide (PP) or gastrin. Basal gastrin levels were 8±2 fmol/ml. The peak increment of gastrin released by bombesin was 95±16, ranatensin 22±6, litorin 18±4, and meal 39±5 fmol/ml. Bombesin caused significantly greater release of gastrin than a meal, litorin or ranatensin (P<0.01) Basal gastric secretion was 23±4 μequiv./min. B9 produced a peak acid secretion of 356±124 μequiv./min. There are no significant difference between the bombesin-like peptides (P<0.01). Basal plasma PP was 38±12 fmol/ml. B9 produced a peak PP increment of 600±50, litorin 137±36, ranatensin 98±11, and a meal 305±58 fmol/ml. B9 released significantly more PP than either litorin or ranatensin (P<0.01). The different amino acid sequences of the peptides are probably responsible for their potency. The substitution of a penultimate phenylalanine residue in litorin and ranabombesin, alytensin, and litorin suggesting that it might have other effects as yet undescribed.

We also recommend Trading Suppliers and Manufacturers of ranatensin M (cas 135727-57-0). Pls Click Website Link as below: cas 135727-57-0 suppliers