title: Inhibition of sodium transport by angiotensin II in the main duct of the rabbit mandibular gland isolated and perfused in vitro.
abstract: The effect of angiotensin II on nett electrolyte transport by the main duct of the rabbit mandibular gland was investigated in vitro using a perfused duct preparation bathed in a Haemaccel -nutrient salt solution. In a bath concentration of 4 X 10(-10) M, angiotensin reduced nett absorption of Na+ and Cl- by about 8% and depolarized the transepithelial electrical potential difference (P.D.) by about 13%; the drug had no effect on ductal transport of K+ and HCO-3. In both lower (4 X 10(-11) M) and higher (4 X 10(-9) M) concentrations, angiotensin had qualitatively similar effects. After exposure to the hormone for about 30 min, Na+ transport and P.D. became unstable and gradually fell away towards zero. It is concluded that angiotensin in physiological concentrations has a specific inhibitory effect on Na+ absorption by salivary duct cells which could arise either from a change in the Na+ pump rate or from a conductance change in the apical or basal membrane of the epithelial cell.
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D008297:Male; D011817:Rabbits; D012964:Sodium / Q000378:metabolism*; D013363:Submandibular Gland / Q000378:metabolism*
chemical_list: D000804:Angiotensin II; D012964:Sodium