The aim of the present study was to determine whether vasopressin affects NaCl reabsorption in the medullary thick ascending limb of the loop of Henle when administered selectively to the luminal membrane. At 5 x 10-6 M and 10-8 M, luminal [Arg8]vasopressin significantly inhibited Cl- transport in the in vitro microperfused rat medullary thick ascending limb by 46.4 ± 5.9% (P < 0.01) and 32.4 ± 2.0% (P < 0.05) respectively. The response to 10-8 M luminal [Arg8]vasopressin was completely blocked by the vasopressin V1 receptor antagonist [β-mercapto-β,β-cyclopenta-methylenepropionyl1,O-Me-Tyr2,Arg8]vasopressin (10-6 M), and was mimicked by the vasopressin V1 receptor agonist [Phe1,Ile5,Orn8]vasopressin (10-8 M; Δ -35.0 ± 4.5%; P < 0.05). Luminal administration of the vasopressin V2 receptor agonist [deamino-Cys1,D-Arg8]vasopressin (5 x 10-6 M) had no effect on transport. These data suggest that luminal vasopressin can inhibit NaCl transport in the medullary thick ascending limb of the rat via vasopressin V1 receptors.
|Number of pages||4|
|Journal||European Journal of Pharmacology|
|State||Published - Oct 10 1996|
Bibliographical noteFunding Information:
These studies were supported by grants from the American Heart Association, Kentucky Affiliate (B.A.J.), NIH grant HL 538 18 (J.C.F.) and NASA EPSCoR WKU 522611 (C.E.O.).
- Ion transport
- Loop of Henle
- Microperfusion, in vitro
ASJC Scopus subject areas