Participation of H1-Receptors in Histamine-Induced Contraction and Relaxation of Horse Coronary Artery In Vitro.
スポンサーリンク
概要
- 論文の詳細を見る
The mechanisms of histamine-induced contraction and relaxation were investigated in rings isolated from a middle part of the left descending coronary arteries of horses. Intact and endothelium-denuded preparations were compared. Rings of horse coronary arteries contracted in response to histamine in a concentration dependent manner, but some of them relaxed with lower concentrations and contracted with higher concentrations. Removal of the endothelium abolished the relaxation and potentiated the contraction. The pD<SUB>2</SUB> values were 4.70±0.08 in the rings with intact endothelium and 4.95±0.08 in endothelium-denuded rings. Histamine-induced contractions in intact and denuded preparations were not affected by an H<SUB>2</SUB>-antagonist, cimetidine, but were inhibited by an H<SUB>1</SUB>-antagonist, diphenhydramine in non-competitive manner in the rings with endothelium and in competitive manner in denuded rings. After precontraction with PGF<SUB>SUP</SUB>2α</SUP> or norepinephrine, histamine relaxed preparations with intact endothelium (pD<SUB>2</SUB> value, 7.80±0.11), although histamine-induced relaxations were not observed in denuded preparations. The relaxation was competitively inhibited by diphenhydramine. Relaxing response was significantly attenuated by methylene blue, quinacrine, L-nitro-arginine, gossypol and AA861 but not by indomethacin. These results suggest that the hisidmine-induced contraction and relaxation in horse coronary arteries are mediated mainly by H<SUB>1</SUB>-receptors in the smooth muscle and endothelium, respectively, and H<SUB>1</SUB>-receptor activation of endothelial cells may liberate vasodilator substance(s).
- 公益社団法人 日本獣医学会の論文
公益社団法人 日本獣医学会 | 論文
- Comparison of serum ferritin and oxidative stress biomarkers between Japanese workers with and without metabolic syndrome
- Somatic Cells Count in Cow's Bulk Tank Milk
- Intestinal Smooth Muscle Cells Locally Enhance Stem Cell Factor (SCF) Production against Gastrointestinal Nematode Infections
- Isolation and Molecular Characterization of Methicillin-Resistant Staphylococci from Horses, Personnel and Environmental Sites at an Equine Hospital in Turkey
- Establishment of Hamster Cell Lines with EGFP-Tagged Human XRCC4 and Protection from Low-Dose X-Ray Radiation