Toda N
Department of Pharmacology, Shiga University of Medical Sciences, Ohtsu, Japan.
Am J Physiol. 1991 May;260(5 Pt 2):H1443-8. doi: 10.1152/ajpheart.1991.260.5.H1443.
Mechanical responses to transmural electrical stimulation, nicotine, norepinephrine, and isoproterenol were compared in cerebral artery strips obtained from Japanese monkeys of different ages (1 mo, 1 yr, 4-7 yr, and greater than 7 yr old). Transmural electrical stimulation produced a contraction in the baby and juvenile monkey arteries contracted with prostaglandin F2 alpha, whereas the older monkey arteries responded to the stimulation with a relaxation. The stimulation-induced contraction was abolished or reversed to a relaxation by phentolamine; the relaxation was not influenced by propranolol and atropine but was abolished by tetrodotoxin, as was the response of the mature monkey arteries. Contractions caused by norepinephrine were greater in baby cerebral arteries than in the older monkey arteries; however, the apparent median effective concentration values did not differ. Middle cerebral artery contractions were greater than those of basilar arteries. The norepinephrine-induced contraction was suppressed by prazosin but not influenced by yohimbine. Isoproterenol (up to 10(-6) M) produced a greater relaxation in the baby arteries than in the older monkey arteries. It is suggested that adrenergic nerves innervating immature monkey cerebral arteries contribute to the regulation of vascular tone predominantly over nonadrenergic, noncholinergic vasodilator nerves, whereas the vasodilator nerves play a major role in the mature monkey arteries. alpha 1-Adrenoceptor subtype appears to be mainly involved in the norepinephrine-induced contraction of baby monkey cerebral arteries, as it is in that of the adult monkey arteries.
比较了不同年龄（1个月、1岁、4 - 7岁和大于7岁）的日本猕猴脑动脉条对跨壁电刺激、尼古丁、去甲肾上腺素和异丙肾上腺素的机械反应。跨壁电刺激使幼猴和幼年猴的动脉产生收缩，该收缩与前列腺素F2α引起的收缩类似，而老年猴的动脉对刺激的反应是舒张。酚妥拉明可消除刺激诱导的收缩或使其转变为舒张；该舒张不受普萘洛尔和阿托品的影响，但被河豚毒素消除，成年猴动脉的反应也是如此。去甲肾上腺素引起的收缩在幼猴脑动脉中比在老年猴动脉中更大；然而，表观半数有效浓度值并无差异。大脑中动脉的收缩大于基底动脉。去甲肾上腺素诱导的收缩被哌唑嗪抑制，但不受育亨宾的影响。异丙肾上腺素（高达10(-6) M）在幼猴动脉中产生的舒张比在老年猴动脉中更大。提示支配未成熟猕猴脑动脉的肾上腺素能神经在血管张力调节中起主要作用，而非肾上腺素能、非胆碱能血管舒张神经作用相对较小，而血管舒张神经在成年猴动脉中起主要作用。α1 - 肾上腺素能受体亚型似乎主要参与去甲肾上腺素诱导的幼猴脑动脉收缩，就像在成年猴动脉中一样。
