Photoaffinity labeling of P2-purinergic and H1-histamine receptors in intact smooth muscle.
Fedan-JS; Hogaboom-GK; Westfall-DP; O'Donnell-JP
Fed Proc 1983 Aug; 42(11):2846-2850
The use of photoaffinity labels in functional studies of receptor mechanisms using smooth muscle was described. The isometric tension of isolated guinea-pig smooth muscle housed in water jacketed, glass organ chambers was recorded in the presence and absence of photoaffinity labels. The effects of photolysis were assessed using spectra of arylazidoaminopropionyl-ATP (ANAPP3), arylazidoaminobutyryl-ATP (ANABP3), and arylazide-histamine (AAH). Photolysis of the three compounds resulted in a decrease of the native absorption of the photoaffinity labels in a time dependent manner. Photolysis of ANAPP3 and ANABP3 but not AAH resulted in an antagonism of ATP induced responses separate from those elicited with norepinephrine, acetylcholine, potassium-chloride, and isoproterenol. The results were discussed with regard to the pharmacological effect of irradiation, the photolysis period, the mechanism and kinetics of pharmacological antagonism, covalent bond formation, time and concentration effects for antagonism, the effect of scavengers on mechanisms of photoaffinity labelling, the qualitative effects of nonphotolyzed and photolyzed compounds, and structure potency relationships in photoaffinity labelling.
NIOSH-Author; Neuromuscular-system; In-vitro-studies; Biochemistry; Neuropharmacology; Autonomic-nervous-system; Laboratory-animals; Muscle-function; Analytical-methods; Photochemical-reactions
Federation Proceedings. 66th Annual Meeting of the Federation of American Societies of Experimental Biology, New Orleans, Louisiana, April 20, 1982