[Effect of microinjection of CRH into rat central nucleus of amygdala on blood pressure and its central mechanism].

The effect of microinjection of corticotropin releasing hormone (CRH) into the central nucleus of amygdala (CeA) on blood pressure was examined in Wistar rats anaesthetized with pentobarbital sodium. The results were as follows: (1) Microinjection of CRH 100, 500 ng into the CeA produced a dose-dependent increase in blood pressure. The response occurred 5 min after injection and lasted for at least 1 h. (2) The response could be blocked by injection of CRH receptor antagonist alpha-helical CRH9-41 into CeA. (3) Lateral ventricle injection of naloxone could also attenuate the pressor response of CRH. (4) After injection of alpha-helical CRH9-41 into nucleus of solitary tract, the pressor response of CRH was diminished. The results suggest that the pressor effect induced by microinjection of CRH into the CeA might be partly mediated through opioid system via a descending pathway from CeA to NTS.