Effect of luminal vasopressin on NaCl transport in the medullary thick ascending limb of the rat.
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 [beta-mercapto-beta,beta-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; delta -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.
Department of Physiology, University of Kentucky, College of Medicine, Lexington 40536-0084, USA.
J
J
Grider
J
J
Falcone
E
E
Kilpatrick
C
C
Ott
B
B
Jackson
D000042:Absorption / Q000187:drug effects; D000704:Analysis of Variance; D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000502:physiology; D001692:Biological Transport / Q000187:drug effects; D006727:Hormone Antagonists / Q000494:pharmacology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism; D007679:Kidney Medulla / Q000378:metabolism*; D007686:Kidney Tubules, Distal / Q000378:metabolism*; D008138:Loop of Henle / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017483:Receptors, Vasopressin / Q000502:physiology; D012965:Sodium Chloride / Q000493:pharmacokinetics*
D006727:Hormone Antagonists; D007473:Ion Channels; D017483:Receptors, Vasopressin; C089517:vasopressin, 1-(2-mercapto-2,2-(cyclopentamethylene)propionic acid)-2-(O-methyl)Tyr-8-Arg-; D001127:Arginine Vasopressin; D012965:Sodium Chloride