First Author | Gericke A | Year | 2011 |
Journal | Invest Ophthalmol Vis Sci | Volume | 52 |
Issue | 7 | Pages | 4795-9 |
PubMed ID | 21613371 | Mgi Jnum | J:181413 |
Mgi Id | MGI:5311286 | Doi | 10.1167/iovs.11-7516 |
Citation | Gericke A, et al. (2011) Functional role of alpha1-adrenoceptor subtypes in murine ophthalmic arteries. Invest Ophthalmol Vis Sci 52(7):4795-9 |
abstractText | PURPOSE: To identify the alpha(1)-adrenoceptor (alpha(1)-AR) subtypes mediating vascular adrenergic responses in murine ophthalmic arteries. METHODS: Expression of mRNA was quantified for individual alpha(1)-AR subtypes in murine ophthalmic arteries using real-time PCR. To assess the functional relevance of alpha(1)-ARs for mediating vascular responses, ophthalmic arteries from mice deficient in one of the three alpha(1)-AR subtypes (alpha(1A)-AR(-/-), alpha(1B)-AR(-/-), and alpha(1D)-AR(-/-), respectively) and wild-type controls were isolated, cannulated with micropipettes, and pressurized. Changes in luminal artery diameter in response to the alpha(1)-AR agonist phenylephrine, the sympathetic transmitter noradrenaline, and to the nonadrenergic vasoconstrictor arginine vasopressin (AVP) were measured by video microscopy. RESULTS: Using real-time PCR, mRNA for all three alpha(1)-AR subtypes was detected in ophthalmic arteries from wild-type mice. In functional studies, phenylephrine and noradrenaline produced dose-dependent constriction of ophthalmic arteries that was similar in wild-type, alpha(1B)-AR(-/-), and alpha(1D)-AR(-/-) mice. Strikingly, responses to phenylephrine and noradrenaline were almost completely abolished in alpha(1A)-AR(-/-) mice. In contrast, the nonadrenergic agonist AVP produced dose-dependent vasoconstrictor responses that did not differ between any of the mouse genotypes tested. CONCLUSIONS: These findings provide evidence that the alpha(1A)-AR subtype mediates adrenergic vasoconstriction in murine ophthalmic arteries. |