Sympathetic inhibition of ascending and descending interneurones during the peristaltic reflex in the isolated guinea-pig distal colon

作     者：Spencer, N McCarron, SL Smith, TK 

作者机构：Univ Nevada Sch Med Dept Physiol & Cell Biol Reno NV 89503 USA 

出 版 物：《JOURNAL OF PHYSIOLOGY-LONDON》 (生理学杂志)

年 卷 期：1999年第519卷第2期

页      面：539-550页

核心收录：

学科分类：0710[理学-生物学] 1001[医学-基础医学(可授医学、理学学位)] 07[理学] 071003[理学-生理学] 

基　　金：NIDDK NIH HHS [R01 DK 45713] Funding Source: Medline 

主　　题：肾上腺素能α激动剂/药理学 肾上腺素能α拮抗剂/药理学 自主神经通路/药物作用 自主神经通路/生理学 结肠/药物作用 结肠/神经支配 结肠/生理学 电刺激 中间神经元/药物作用 中间神经元/生理学 肌收缩/药物作用 肌收缩/生理学 烟碱激动剂/药理学 副交感神经系统/药物作用 副交感神经系统/生理学 蠕动/药物作用 蠕动/生理学 反射/药物作用 反射/生理学 交感神经系统/药物作用 交感神经系统/生理学 突触传递/药物作用 突触传递/生理学 动物 豚鼠 

摘      要：1. We investigated the effects of sympathetic nerve stimulation within ascending and descending reflex pathways underlying the peristaltic reflex in the guinea-pig distal colon. 2. A three-chambered partitioned bath was used to divide a segment of distal colon into stimulation, recording and intermediate regions. The effects of lumbar colonic nerves (LCN) could be localized to the intermediate region by surgical lesions of the mesentery and by application of guanethidine (3 mu M) to the stimulation and recording chambers. 3. Brush stroking the mucosa in the anal and oral stimulation chambers elicited a synchronous contraction of the longitudinal muscle (LM) and circular muscle (CM) oral to, and transient relaxation of the LM and CM anal to, the stimulus, respectively. 4. After N-omega-nitro-L-arginine (L-NA;100 mu M) in the oral and intermediate chambers, mucosal stimulation in the oral chamber elicited a prolonged descending inhibitory and excitatory complex in both the LM and CM in the anal recording chamber. This was blocked by hexamethonium (300 mu M), which did not affect the transient relaxation response recorded in control conditions. 5. Stimulation of the LCN (1200 pulses, 20 Hz), delivered to the intermediate region, abolished the oral contraction and the L-NA-induced anal, complex in both the LM and CM, but was without effect on the transient hexamethonium-resistant anal relaxation. These effects of LCN stimulation were reversed by phentolamine (3 mu M) or yohimbine (100 nM), but not propranolol(10 mu M), when added to the intermediate chamber. 6. LCN stimuli (2-20 Hz, 600 mu s pulses) directed to the recording chamber elicited synchronous relaxations in the LM and CM that were unaffected by hexamethonium (300 mu M), but were reduced by yohimbine and usually blocked by the further addition of propranolol(10 mu M). 7. In conclusion, sympathetic nerve stimulation inhibits orally and anally projecting cholinergic interneurones underlying the peristaltic refle