An inhibitory prejunctional 5-HT1-like receptor in the isolated perfused rat kidney. Apparent distinction from the 5-HT1A, 5-HT1B and 5-HT1C subtypes.
The present study has identified a receptor for 5-hydroxytryptamine (5-HT) which functions to inhibit the stimulus-induced release of [3H] noradrenaline following sympathetic periarterial nerve stimulation to the isolated perfused rat kidney. In addition to 5-HT (IC30 = 4.5 X 10(-8) mol/l), both 5-carboxamidotryptamine (IC30 = 8 X 10(-9) mol/l) and 5-methoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl) indole (RU-24969, IC30 = 2.5 X 10(-7) mol/l) acted as agonists whereas 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) was inactive. The inhibitory effect of 5-HT on the electrically-evoked release of tritium was antagonized in a concentration-dependent manner by methiothepin (IC50 = 4 X 10(-9) mol/l), metergoline (IC50 = 4 X 10(-8) mol/l) and methysergide (IC50 = 1.3 X 10(-7) mol/l) but not by cyproheptadine, ketanserin, mesulergine, (-)-propranolol, (+/-)-pindolol, (+/-)-cyanopindolol, metoclopramide or phentolamine. It is concluded that the receptor to 5-HT conforms to general criteria defining 5-HT1-like receptors but at the present time the receptor site cannot be fitted to the designated 5-HT1A, 5-HT1B or 5-HT1C subtypes.
D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000302:isolation & purification; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000187:drug effects; D014662:Vasoconstrictor Agents
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014662:Vasoconstrictor Agents; D012701:Serotonin; D009638:Norepinephrine