猫脊髓软膜小动脉对去甲肾上腺素的反应。

The response of feline spinal pial arterioles to norepinephrine.

作者信息

Crawford R A, Gregory P C, Griffiths I R

出版信息

J Neurosurg. 1980 Jan;52(1):60-3. doi: 10.3171/jns.1980.52.1.0060.

DOI:10.3171/jns.1980.52.1.0060

Abstract

The effect of norepinephrine on the diameter of feline spinal pial arteries and arterioles was studied by microapplication of the drug to the perivascular environment. Vascular diameter was determined by the television image-splitting method. Application of norepinephrine over the range of 5 x 10(-8) M to 5 x 10(-3) M to spinal pial arterioles resulted in constriction of the vessels. The dose-response curve showed a tendency to plateau at concentrations above 5 x 10(-5) M, with a maximal constriction of 28.8 +/- 5.1% at 5 x 10(-3) M. The reduction in vessel diameter to microapplication of norepinephrine was prevented with the inclusion of an equimolar concentration of the alpha-adrenergic blocker, phentolamine, in the injectate. The data indicate the presence of alpha-adrenergic receptors on the smooth muscle of spinal pial arterioles, and it is suggested that the arguments pertaining to the sympathetic control of blood flow in the brain apply also to the spinal cord.

摘要

通过将去甲肾上腺素微量应用于血管周围环境，研究了其对猫脊髓软膜动脉和小动脉直径的影响。血管直径采用电视图像分割法测定。将5×10⁻⁸ M至5×10⁻³ M范围内的去甲肾上腺素应用于脊髓软膜小动脉，可导致血管收缩。剂量-反应曲线显示，在浓度高于5×10⁻⁵ M时趋于平稳，在5×10⁻³ M时最大收缩率为28.8±5.1%。在注射剂中加入等摩尔浓度的α-肾上腺素能阻滞剂酚妥拉明，可防止去甲肾上腺素微量应用导致的血管直径减小。数据表明脊髓软膜小动脉平滑肌上存在α-肾上腺素能受体，提示有关大脑血流交感神经控制的观点也适用于脊髓。