Comparison of noradrenaline and lysosphingolipid-induced vasoconstriction in mouse and rat small mesenteric arteries.
1 We have compared vasoconstriction responses in isolated mesenteric small arteries from mice and rats as elicited by KCl, noradrenaline and the lysosphingolipids sphingosine-1-phosphate (S1P) and sphingosylphosphorylcholine (SPC). 2 Contractile responses to KCl and noradrenaline, but not those of S1P or SPC, were significantly related to vessel diameter in both species. 3 When comparing vessels of similar diameter, contractile responses for KCl and the three agonists were much smaller in mice than in rats, e.g. 8.3 +/- 0.4 vs. 14.7 +/- 0.7 mn for noradrenaline. 4 Based upon the antagonist rank order of potency of prazosin (pKB 8.80) > B8805-033 (pKB 7.89) > yohimbine (pKB 6.18) approximately BMY 7378 (pA2 6.03), noradrenaline responses in mice were mediated solely via alpha1A-adrenoceptors, similar to what repeatedly has been shown in rats. 5 The S1P3 receptor antagonist suramin (100 microM) significantly inhibited responses to S1P and SPC in rats but not in mice, and did not affect noradrenaline responses in either species. 6 We conclude that for any given diameter, mouse mesenteric arteries develop less contraction in response to various stimuli. Noradrenaline acts via alpha1A-adrenoceptors in both species. Responses to S1P and SPC differ between both species with regard to suramin-sensitivity indicating involvement of different receptor subtypes for lysosphingolipids in both species.
Hedemann
J
J
Department of Medicine, University of Essen, 45122 Essen, Germany.
Fetscher
C
C
Michel
M C
MC
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008246:Lysophospholipids / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000294:innervation; D051379:Mice; D008810:Mice, Inbred C57BL; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013107:Sphingolipids / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D000317:Adrenergic alpha-Antagonists; D008246:Lysophospholipids; D013107:Sphingolipids; D014662:Vasoconstrictor Agents; C005356:sphingosine phosphorylcholine; D010767:Phosphorylcholine; C060506:sphingosine 1-phosphate; D011189:Potassium Chloride; D013110:Sphingosine; D009638:Norepinephrine