P物质可增加长时间电场刺激诱发的灌流大鼠肾上腺髓质儿茶酚胺的分泌。

Substance P increases catecholamine secretion from perfused rat adrenal glands evoked by prolonged field stimulation.

作者信息

Zhou X F, Livett B G

机构信息

Department of Biochemistry, University of Melbourne, Parkville, Victoria, Australia.

出版信息

J Physiol. 1990 Jun;425:321-34. doi: 10.1113/jphysiol.1990.sp018105.

DOI:10.1113/jphysiol.1990.sp018105

PMID:1698977

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1189850/

Abstract

We have studied the effect of substance P (SP) on catecholamine (CA) secretion evoked by prolonged field stimulation from the perfused rat adrenal gland in vitro. 2. Previous studies show that SP has an inhibitory effect on the nicotinic response in a number of different tissue preparations. In the present study, we found that SP at concentrations from 10(-7) to 10(-6) M markedly increased CA secretion evoked by prolonged high-frequency field stimulation but not that evoked by low-frequency field stimulation. 3. In the absence of field stimulation SP by itself had no direct effect on CA secretion. This indicates that SP acts as a neuromodulator rather than a neurotransmitter to increase CA secretion from the adrenal medulla. 4. The nicotinic receptors were still functional following a period of prolonged field stimulation (120 min) because CA secretion was markedly increased in response to the nicotinic agonist dimethylphenylpiperazinium (DMPP). 5. Capsaicin pre-treatment reduced CA secretion evoked by prolonged field stimulation and the facilitatory action of SP on CA secretion lasted longer in these capsaicin-pre-treated rats than in controls, indicating that SP-containing capsaicin-sensitive fibres innervating the adrenal medulla may be involved in the regulation of CA secretion. 6. In parallel with the increase in CA secretion, 3H overflow from the splanchnic nerve pre-labelled with [3H]choline was also increased by SP. The increase in CA secretion by SP lasted longer than the increase in 3H overflow. These results suggest that SP facilitates CA secretion from the adrenal gland at two levels: (1) pre-synaptically by facilitating ACh release from splanchnic nerve terminals, and (2) post-synaptically by modulating the nicotinic secretory response by protection against nicotinic desensitization of secretion. 7. The present studies provide further evidence that endogenous SP in the splanchnic nerve may modulate CA secretion during stress.

摘要

我们研究了P物质（SP）对体外灌注大鼠肾上腺经长时间场刺激诱发的儿茶酚胺（CA）分泌的影响。2. 先前的研究表明，SP对多种不同组织制剂中的烟碱样反应具有抑制作用。在本研究中，我们发现浓度为10⁻⁷至10⁻⁶ M的SP显著增加了长时间高频场刺激诱发的CA分泌，但对低频场刺激诱发的CA分泌没有影响。3. 在无场刺激时，SP自身对CA分泌无直接作用。这表明SP作为一种神经调质而非神经递质来增加肾上腺髓质的CA分泌。4. 在长时间场刺激（120分钟）后，烟碱样受体仍有功能，因为对烟碱样激动剂二甲基苯基哌嗪鎓（DMPP）的反应中CA分泌显著增加。5. 辣椒素预处理减少了长时间场刺激诱发的CA分泌，并且在这些经辣椒素预处理的大鼠中，SP对CA分泌的促进作用持续时间比对照组更长，这表明支配肾上腺髓质的含SP的辣椒素敏感纤维可能参与了CA分泌的调节。6. 与CA分泌增加同时，经[³H]胆碱预标记的内脏神经的³H溢出也因SP而增加。SP引起的CA分泌增加持续时间比³H溢出增加持续时间更长。这些结果表明，SP在两个水平促进肾上腺的CA分泌：（1）通过促进内脏神经末梢释放乙酰胆碱在突触前起作用，以及（2）通过防止分泌的烟碱样脱敏来调节烟碱样分泌反应在突触后起作用。7. 本研究提供了进一步的证据，表明内脏神经中的内源性SP可能在应激期间调节CA分泌。