Durability of crystalline monumental stones in terms of their petrophysical characteristics
Year: 2009
Type: article
Abstract: 1. Calcium mediated contractile effects were evoked in phenoxybenzamine (10(-7) M)-pretreated dog saphenous vein (DSV) rings under the continuing presence of norepinephrine (3 x 10(-5) M), a condition that selectively activates alpha 2 (alpha 2)-adrenergic receptors. 2. Calcium-induced contractions in this model were dose-dependently inhibited by the alpha 2 antagonists rauwolscine and SKF-86466, while the calcium channel blockers nifedipine and verapamil produced only small non-dose related inhibitions. The receptor antagonists sulpiride, buspirone, pyrilamine and atropine showed no inhibitory effect. 3. In contrast, rauwolscine and SKF-86466 produced no inhibition of the calcium-evoked contractions in potassium-depolarized DSV rings, in which nifedipine and verapamil exhibited potent calcium antagonist activity. 4. These data provide evidence to support the presence of alpha 2 related receptor-operated calcium channels in vascular smooth muscle, which are pharmacologically distinguishable from potential-dependent calcium channels.
Source: PubMed
Author: Kovacs, Timea <1982>
Language: English
Subfield: Earth-Surface Processes
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1980472