[Effects of angiotensin peptides on airway epithelial ion transport and its modulation by angiotensin converting enzyme].
To study the effects of angiotensin (ANG) peptides on airway epithelial ion transport function, we evaluated the bioelectric properties of canine cultured tracheal epithelium under short-circuit conditions in vitro. Addition of ANG I, II and II dose-dependently increased short-circuit current (Isc) and transepithelial potential difference, an effect that was more pronounced with addition to the submucosal solution than to the mucosal solution, with rank order of potency of ANG II greater than or equal to ANG II much greater than ANG I. The ANG-induced increase in Isc was not altered by the Na channel blocker amiloride, but was greatly reduced by the CI channel blocker diphenylamine-2-carboxylate and Cl-free medium. The response of Isc to ANG I was reduced by MK422, an angiotensin converting enzyme inhibitor, in a dose-dependent fashion. These results suggest that ANG II and III selectively stimulate Cl secretion across airway epithelium and that ANG I may exert its effect after its conversion to ANG II by angiotensin converting enzyme.
Tamaoki
J
J
First Department of Medicine, Tokyo Women's Medical College.
Isono
K
K
Chiyotani
A
A
Kanemura
T
T
Sakai
N
N
Konno
K
K
D000803:Angiotensin I / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology*; D000805:Angiotensin III / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D002713:Chlorine / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D015773:Enalaprilat / Q000494:pharmacology; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D017136:Ion Transport / Q000187:drug effects; D007703:Peptidyl-Dipeptidase A / Q000502:physiology*; D014132:Trachea / Q000378:metabolism*
D000804:Angiotensin II; D000805:Angiotensin III; D002713:Chlorine; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; D015773:Enalaprilat