Dev B R, Philip L
Department of Physiology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
Brain Res Bull. 1996;40(2):111-6. doi: 10.1016/0361-9230(95)02145-0.
Drug-induced alterations in arterial blood pressure are reflected in the extracellular fluid neurotransmitter levels of the nucleus of the solitary tract (NTS). Urethane-anesthetized spontaneously hypertensive rats (SHRs) and Wistar-Kyoto normotensive (WKY) rats were used in this study. The extracellular neurochemical profile of the NTS was quantified using the in vivo microdialysis technique. In SHR, phenylephrine-induced hypertension produced no significant changes in the extracellular norepinephrine (NE) and dihydroxyphenylacetic acid concentrations, whereas a significant increase in the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) concentration was observed. Wistar normotensive rats, in response to phenylephrine-induced hypertension, showed a significant increase in extracellular NE and 5-HIAA concentrations. Hypotension produced by the intravenous infusion of nitroprusside failed to show significant changes in the extracellular neurotransmitters in both SHR and WKY rats. However, there was a significant increase in 5-HIAA concentration in SHRs during the rebound hypertension, which followed the nitroprusside-infused hypotension. No such change was observed in the case of the WKY rats. These results suggest the possible involvement of the serotonergic mechanisms of NTS in the regulation of normal arterial blood pressure in these two rat strains.
药物引起的动脉血压变化反映在孤束核（NTS）的细胞外液神经递质水平上。本研究使用了乌拉坦麻醉的自发性高血压大鼠（SHR）和Wistar-Kyoto正常血压大鼠（WKY）。采用体内微透析技术对NTS的细胞外神经化学特征进行定量分析。在SHR中，去氧肾上腺素诱导的高血压并未使细胞外去甲肾上腺素（NE）和二羟基苯乙酸浓度发生显著变化，然而，血清素代谢物5-羟吲哚乙酸（5-HIAA）浓度却显著升高。Wistar正常血压大鼠在去氧肾上腺素诱导的高血压作用下，细胞外NE和5-HIAA浓度显著增加。静脉输注硝普钠引起的低血压在SHR和WKY大鼠中均未使细胞外神经递质发生显著变化。然而，在硝普钠输注引起的低血压后的反跳性高血压期间，SHR的5-HIAA浓度显著增加。WKY大鼠未观察到这种变化。这些结果表明，NTS的血清素能机制可能参与了这两种大鼠品系正常动脉血压的调节。
