Parker R E, Hall R E, Marr H B, Skinner N S
Am J Physiol. 1979 Sep;237(3):H386-91. doi: 10.1152/ajpheart.1979.237.3.H386.
The present studies investigated vascular responses to electrical stimulation of the posterior hypothalamus in isolated but perfused and innervated subcutaneous adipose tissue in adult dogs. Three groups of dogs were distinguished: in one, electrical stimulation elicited vasodilation; in another, vasoconstriction, and in a third, neither significant vasodilation nor vasoconstriction occurred. Histological examination revealed that electrode placements were in the medial posterior hypothalamus, the lateral posterior hypothalamus, and the medial septal region, respectively. Hypothalamic stimulation failed to alter concentrations of free fatty acids or glycerol in venous blood from subcutaneous fat. Local beta-adrenergic block (propranolol) reversed the vasodilation to vasoconstriction while local alpha-adrenergic block (dihydroergotamine) abolished the vaso constrictor response. These results suggest that selective stimulation of the posterior hypothalamus results in neurogenic activation of both alpha- and beta-adrenergic mechanisms in adipose tissue vasculature. beta-Adrenergic vasodilation appears to predominate if the electrode is located medially, and alpha-adrenergic vasoconstriction appears to predominate if the electrode is located in the lateral posterior hypothalamus.
本研究探讨了成年犬离体但灌注且有神经支配的皮下脂肪组织对下丘脑后部电刺激的血管反应。区分出三组犬：一组中，电刺激引起血管舒张；另一组中，引起血管收缩；第三组中，既未出现明显的血管舒张也未出现血管收缩。组织学检查显示，电极分别置于下丘脑后部内侧、下丘脑后部外侧和内侧隔区。下丘脑刺激未能改变皮下脂肪静脉血中游离脂肪酸或甘油的浓度。局部β-肾上腺素能阻滞（普萘洛尔）使血管舒张转变为血管收缩，而局部α-肾上腺素能阻滞（双氢麦角胺）则消除了血管收缩反应。这些结果表明，选择性刺激下丘脑后部会导致脂肪组织血管中α-和β-肾上腺素能机制的神经源性激活。如果电极位于内侧，β-肾上腺素能血管舒张似乎占主导；如果电极位于下丘脑后部外侧，α-肾上腺素能血管收缩似乎占主导。
