人体离体皮肤动脉在冷却过程中的α1和α2肾上腺素能反应。
Alpha 1- and alpha 2-adrenergic response in human isolated skin arteries during cooling.
作者信息
Gómez B, Borbujo J, García-Villalón A L, Nava-Hernández E, Valle J, García J L, Diéguez G
机构信息
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid, Espãna.
出版信息
Gen Pharmacol. 1991;22(2):341-6. doi: 10.1016/0306-3623(91)90461-e.
PMID:1647346
Abstract
- Dose-response curves for noradrenaline, phenylephrine and clonidine were determined isometrically in 2-mm cylindrical segments from human skin arteries at 24 degrees C and compared to those previously reported at 37 degrees C. 2. Noradrenaline (3 x 10(-10)-3 x 10(-4) M) induced dose-dependent contraction and the sensitivity was increased during cooling. Phentolamine (10(-6) M), prazosin (10(-6) M) or yohimbine (10(-6) M) produced a higher rightward shift of the control curve for noradrenaline during cooling. 3. Phenylephrine (10(-11)-3 x 10(-4) M) and clonidine (10(-11)-10(-6) M) caused dose-dependent contraction and the sensitivity of the arteries was augmented at 24 degrees C. 4. The arteries also showed a lower maximal contraction to the adrenergic agonists used and KCl (50 mM) during cooling. 5. The results suggest that cooling: (a) increases sensitivity of postjunctional alpha 1- and alpha 2-adrenoceptors in human skin arteries and (b) depresses contractility of these arteries to alpha-adrenergic stimulation and direct activation of vascular smooth muscle.
摘要
- 在24摄氏度下，以等长方式测定了去甲肾上腺素、苯肾上腺素和可乐定在人皮肤动脉2毫米圆柱形节段中的剂量-反应曲线，并与之前在37摄氏度时报道的曲线进行了比较。2. 去甲肾上腺素（3×10⁻¹⁰ - 3×10⁻⁴ M）引起剂量依赖性收缩，且在冷却过程中敏感性增加。酚妥拉明（10⁻⁶ M）、哌唑嗪（10⁻⁶ M）或育亨宾（10⁻⁶ M）在冷却过程中使去甲肾上腺素的对照曲线向右有更大的偏移。3. 苯肾上腺素（10⁻¹¹ - 3×10⁻⁴ M）和可乐定（10⁻¹¹ - 10⁻⁶ M）引起剂量依赖性收缩，且在24摄氏度时动脉的敏感性增强。4. 在冷却过程中，这些动脉对所用肾上腺素能激动剂和氯化钾（50 mM）的最大收缩也较低。5. 结果表明，冷却：（a）增加人皮肤动脉节后α1和α2肾上腺素能受体的敏感性，（b）降低这些动脉对α肾上腺素能刺激和血管平滑肌直接激活的收缩性。
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