Partial agonistic activity of GR43175 at the inhibitory prejunctional 5-HT1-like receptor in rat kidney.
1. The pharmacological effect of the selective 5-HT receptor agonist GR43175 has been studied in the isolated perfused rat kidney with particular reference to the inhibitory prejunctional 5-HT1-like receptor. 2. GR43175 (1 x 10(-8) to 1 x 10(-5) M) inhibited the electrically evoked release of tritium from renal noradrenergic nerves but did not affect the basal (non-stimulated) release of tritium or perfusion pressure. 3. The inhibitory prejunctional action of GR43175, as well as that of 5-HT, was blocked by methiothepin, suggesting that both agonists act at the inhibitory 5-HT1-like site. 4. GR43175, relative to 5-HT, acted as a weak partial agonist at the inhibitory prejunctional 5-HT1-like receptor and antagonized 5-HT-induced inhibition of tritium release, suggesting again that a common site of action is involved. 5. The results support the conclusion that the 5-HT1-like receptor activated by GR43175 in the rat kidney is very similar to that identified in dog saphenous vein and certain other tissues.
Bond
R A
RA
Department of Pharmacology, University of Houston, Texas 77204-5515.
Craig
D A
DA
Charlton
K G
KG
Ornstein
A G
AG
Clarke
D E
DE
D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D008297:Male; D008719:Methiothepin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology*; D018170:Sumatriptan; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism
D007211:Indoles; D011985:Receptors, Serotonin; D013449:Sulfonamides; D012701:Serotonin; D008719:Methiothepin; D018170:Sumatriptan