Chan J Y, Barnes C D, Chan S H
Department of Medical Research, Taipei Veterans General Hospital, Taiwan, Republic of China.
Regul Pept. 1990 Jul 30;29(2-3):199-213. doi: 10.1016/0167-0115(90)90083-9.
Modulation of baroreceptor reflex (BRR) by endogenous substance P (SP) in the brain was investigated in rats anesthetized with pentobarbital sodium. Intracerebroventricular administration of the undecapeptide (15 or 30 nmol) and its antagonist, (D-Pro2, D-Trp7,9)-SP (30 or 60 nmol) or SP antiserum (1:20), respectively, promoted a significant increase and decrease in the sensitivity of BRR response. Prolonging the endogenous activity of SP with the aminopeptidase blocker, bestatin (200 nmol) or with the endopeptidase-24.11 inhibitor, phosphoramidon (200 nmol) significantly augmented the same reflex. Combining the undecapeptide with either peptidase blocker, moreover, promoted additional potentiation of the BRR response. On the other hand, simultaneous administration of bestatin and (D-Pro2, D-Trp7,9)-SP produced a reduction of the augmented effect of bestatin on the sensitivity of BRR response. Bilateral microinjection of SP (600 pmol) or an antiserum against SP (1:20) into the nucleus tractus solitarius (NTS) elicited respectively an enhancement of and reduction in the BRR response. These data suggest that neurons that contain SP may participate in central cardiovascular control by tonically enhancing the sensitivity of the BRR response, possibly via an action on the NTS.
在戊巴比妥钠麻醉的大鼠中，研究了脑内内源性P物质（SP）对压力感受器反射（BRR）的调节作用。分别向脑室内注射十一肽（15或30 nmol）及其拮抗剂（D-脯氨酸2，D-色氨酸7,9）-SP（30或60 nmol）或SP抗血清（1:20），可显著提高和降低BRR反应的敏感性。用氨肽酶抑制剂贝司他汀（200 nmol）或内肽酶-24.11抑制剂磷酰胺（200 nmol）延长SP的内源性活性，可显著增强相同的反射。此外，将十一肽与任何一种肽酶抑制剂联合使用，可进一步增强BRR反应。另一方面，同时给予贝司他汀和（D-脯氨酸2，D-色氨酸7,9）-SP可降低贝司他汀对BRR反应敏感性的增强作用。向孤束核（NTS）双侧微量注射SP（600 pmol）或抗SP抗血清（1:20）分别可增强和降低BRR反应。这些数据表明，含有SP的神经元可能通过对NTS的作用，以紧张性增强BRR反应的敏感性来参与中枢心血管控制。
