McPherson G A, Bevan J A
J Pharmacol Exp Ther. 1987 Jan;240(1):99-105.
Studies were performed on several superficial veins from the rabbit face to examine the relationship between beta adrenoceptor subtype distribution, intrinsic myogenic tone and sympathetic nerve innervation. Experiments using selective beta adrenoceptor agonists and antagonists indicate that the dorsal nasal and angularis oculi veins possess a homogeneous population of beta-2 adrenoceptors. Sympathetic nerve stimulation in these segments results only in contraction mediated through postjunctional alpha adrenoceptors. These segments are devoid of intrinsic myogenic tone. In the facial vein, of which both veins are tributaries, both beta-1 and beta-2 adrenoceptors are found. Studies with the beta-1 adrenoceptor antagonist, betaxolol, and beta-2 adrenoceptor antagonist, ICI 118,551, indicate that the prominent relaxation observed in this tissue to sympathetic nerve stimulation is mediated through postjunctional beta-1 adrenoceptors. At physiological temperatures, the facial vein possesses a marked intrinsic myogenic tone that is inhibited by this beta-1 adrenoceptor-mediated sympathetic activity. Considering the anatomical relationship between these vessels and the unique association between beta adrenoceptor subtype, intrinsic myogenic tone and sympathetic innervation, it is possible that facial blood redistribution in the rabbit can be markedly affected by sympathetic nerve stimulation. Such a process could have an important role in cranial thermoregulation.
对兔面部的几条浅静脉进行了研究，以探讨β肾上腺素能受体亚型分布、内在肌源性张力和交感神经支配之间的关系。使用选择性β肾上腺素能受体激动剂和拮抗剂的实验表明，鼻背静脉和眼内角静脉具有均一的β2肾上腺素能受体群体。这些节段的交感神经刺激仅导致通过节后α肾上腺素能受体介导的收缩。这些节段没有内在肌源性张力。在作为其两条属支的面静脉中，发现了β1和β2肾上腺素能受体。使用β1肾上腺素能受体拮抗剂倍他洛尔和β2肾上腺素能受体拮抗剂ICI 118,551的研究表明，该组织中观察到的对交感神经刺激的明显舒张是通过节后β1肾上腺素能受体介导的。在生理温度下，面静脉具有明显的内在肌源性张力，该张力受到这种β1肾上腺素能受体介导的交感神经活动的抑制。考虑到这些血管之间的解剖关系以及β肾上腺素能受体亚型、内在肌源性张力和交感神经支配之间的独特关联，兔面部的血液重新分布可能会受到交感神经刺激的显著影响。这样一个过程可能在颅部体温调节中起重要作用。
