Attenuated 5-HT2 receptor-mediated responses in hindquarters of diabetic rats.
Vasoconstrictor responses to 5-hydroxytryptamine (5-HT), alpha-methyl-5-HT, endothelin-1, arachidonic acid and the thromboxane A2-mimetic U46619 ((15S)-hydroxy-11 alpha, 9 alpha-(epoxymethano)prosta-5Z,13E-dienoic acid) were obtained in blood-perfused hindquarters of 6-week streptozotocin-diabetic rats. When compared to responses obtained in hindquarters of control rats, responses to 5-HT, alpha-methyl-5-HT, and arachidonic acid were attenuated in hindquarters of diabetic rats. However, responses to endothelin-1 or U46619 were not significantly different between controls and diabetics. These results suggest that 5-HT2, but not endothelin ETA receptor-mediated responses are reduced in hindquarters of diabetic rats. The results utilising arachidonic acid and U46619 suggest that there may also be a defect in the cyclo-oxygenase cascade during diabetes.
James
G M
GM
Department of Pharmacology, Monash University, Clayton, Victoria, Australia.
Hodgson
W C
WC
D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D019332:Endothelin-1 / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006614:Hindlimb / Q000098:blood supply*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D010477:Perfusion; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D001786:Blood Glucose; D019332:Endothelin-1; D007004:Hypoglycemic Agents; D007328:Insulin; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C042390:alpha-methylserotonin; D016718:Arachidonic Acid; D012701:Serotonin; D007650:Ketanserin