| First Author | Neidhold S | Year | 2007 |
| Journal | Br J Pharmacol | Volume | 150 |
| Issue | 3 | Pages | 261-70 |
| PubMed ID | 17179950 | Mgi Jnum | J:135912 |
| Mgi Id | MGI:3794795 | Doi | 10.1038/sj.bjp.0706980 |
| Citation | Neidhold S, et al. (2007) The function of alpha- and beta-adrenoceptors of the saphenous artery in caveolin-1 knockout and wild-type mice. Br J Pharmacol 150(3):261-70 |
| abstractText | BACKGROUND AND PURPOSE: Adrenoceptors can associate with cardiac caveolae. To investigate the function of vascular caveolae, adrenoceptor-mediated effects were compared in the saphenous artery of caveolin-1 knockout (cav-1KO) and wild-type (WT) mice. EXPERIMENTAL APPROACH: Electronmicroscopy was used to detect caveolae. Real-Time quantitative PCR was used for adrenoceptor subtypes. Catecholamine-evoked contractions and relaxations were studied in arterial segments. KEY RESULTS: Caveolae were found in arterial smooth muscle from WT but not from cav-1KO mice. Arterial mRNA levels for the adrenoceptors alpha1A, alpha1B, alpha1D, beta1, beta2 and beta3 were similar in cav-1KO and WT. (-)-Noradrenaline contracted cav-1KO (-log EC50M=7.1) and WT (-log EC50M=7.3) arteries through prazosin-sensitive receptors. Maximum (-)-noradrenaline-evoked contractions were greater in cav-1KO than WT arteries. (-)-Isoprenaline relaxed WT arteries (-log EC50M=7.3) more potently than cav-1KO arteries (-log EC50M=6.8); the effects were antagonized partially and similarly by the beta2-selective antagonist ICI118551 (50 nM). The (-)-isoprenaline-evoked relaxation was partially antagonized by the beta1-adrenoceptor-selective antagonist CGP20712 (300 nM) in WT but not cav-1KO arteries. The beta3-adrenoceptor-selective antagonist L748337 (100 nM) partially antagonized the relaxant effects of (-)-isoprenaline in cav-1KO but not in WT arteries. BRL37344 partially relaxed arteries through beta3-adrenoceptors in cav-1KO but not WT. The relaxant effects of BRL37344 were decreased by the NO synthase inhibitor OmegaL-nitroarginine. CONCLUSIONS AND IMPLICATIONS: The function of arterial alpha1- and beta2-adrenoceptors is similar in cav-1KO and WT mice. beta1-adrenoceptor-mediated relaxation in WT is lost in cav-1KO and replaced by the appearance of beta3-adrenoceptors. |
