血管活性肠肽抗血清对绵羊大脑中动脉血管舒张神经传递的抑制作用。

Inhibition of vasodilator neurotransmission in the sheep middle cerebral artery by VIP antiserum.

Matthew J D, Wadsworth R M, McPhaden A R

Department of Physiology and Pharmacology, University of Strathclyde Glasgow, UK.

J Auton Pharmacol. 1997 Feb;17(1):13-9. doi: 10.1046/j.1365-2680.1997.00435.x.

Abstract

Middle cerebral artery rings from the sheep were relaxed by vasoactive intestinal peptide (VIP) (20-200 nM) or by stimulation of the vasodilator nerves, electrical field stimulation (EFS). 2. VIP antiserum 1:256 inhibited the relaxation produced by both exogenous VIP (from 70 +/- 5 to 32 +/- 9% of 5-HT-induced tone at 200 nM VIP) and by EFS (from 43 +/- 5 to 26 +/- 6% of 5-HT-induced tone after 20 min), while pre-immune serum was inactive. 3. Capsaicin (1 microM) produced a transient relaxation but did not alter the response to EFS which was subsequently inhibited by addition of L-NOArg (100 microM). VIP-induced relaxation was antagonized by L-NOArg (50 microM) (from 68 +/- 5 to 46 +/- 2% relaxation of 5-HT-induced tone) but not by D-NOArg. 4. Exogenous VIP produced an approximately 2.4-fold increase in cyclic GMP content which was prevented by preincubation with L-NOArg (100 microM) but not D-NOArg. 5. VIP and neuronal NOS immunoreactivity was co-localized to the same adventitial nerve fibres in the sheep middle cerebral artery. 6. These results provide evidence that neurogenic relaxation in the sheep middle cerebral artery is, at least in part, mediated by VIP, involving activation of NO synthase.

摘要

绵羊大脑中动脉环可被血管活性肠肽（VIP）（20 - 200 nM）或通过刺激血管舒张神经，即电场刺激（EFS）而舒张。2. VIP抗血清1:256抑制外源性VIP（在200 nM VIP时，从5 - HT诱导张力的70±5%降至32±9%）和EFS（20分钟后，从5 - HT诱导张力的43±5%降至26±6%）所产生的舒张作用，而免疫前血清则无此作用。3. 辣椒素（1 μM）产生短暂舒张，但不改变对EFS的反应，随后加入L - NOArg（100 μM）可抑制该反应。VIP诱导的舒张被L - NOArg（50 μM）拮抗（从5 - HT诱导张力的68±5%舒张降至46±2%），但不被D - NOArg拮抗。4. 外源性VIP使环磷酸鸟苷含量增加约2.4倍，预先与L - NOArg（100 μM）孵育可阻止此增加，但D - NOArg则不能。5. VIP和神经元型一氧化氮合酶免疫反应性共定位于绵羊大脑中动脉的同一外膜神经纤维。6. 这些结果提供了证据，表明绵羊大脑中动脉的神经源性舒张至少部分是由VIP介导的，涉及一氧化氮合酶的激活。