Effects of bombesin,calcitonin, and enkephalin on canine jejunal water and electrolyte transport

The aim of this investigation was to study the effects of the peptides bombesin, calcitonin, and enkephalin on net jejunal water and electrolyte fluxes using the triple-lumen gut perfusion technique in conscious dogs. Intestinal transport was measured during intravenous infusions of bombesin (1 microgram/kg/hr, 8 studies), or calcitonin (3 micrograms/kg/hr, 5 studies), or methionine enkephalin (20 micrograms/kg/hr, 6 studies); each dog was used as its own control with infusion of 150 mmol/liter NaCl preceding and succeeding each peptide infusion. Net water absorption was reduced from a control value of 17 +/- 4.18 to 7 +/- 1.79 microliter/cm/min by bombesin (P less than 0.05) and increased from a control value of 15 +/- 3.95 to 29 +/- 5.58 microliters/cm/min by enkephalin (P less than 0.05). Bombesin reduced net sodium and chloride absorption, while enkephalin increased net absorption of sodium and bicarbonate. Calcitonin did not have any detectable effect in the dose used in this study in dogs. We conclude that bombesin and enkephalin can effect the transport of water and electrolytes in the canine jejunum.