title: Effect of intracarotid administration of adrenomedullin on the spontaneous electrical activity of area postrema neurons in sino-aortic denervated rats.
abstract: To observe the effect of intracarotid administration of adrenomedullin (AM) on the spontaneous electrical activity of area postrema (AP) neurons, 78 spontaneous active units were recorded from 63 sino-aortic denervated Sprague-Dawley rats using extracellular recording technique. The results obtained are as follows. (1) Following intracarotid administration of AM (0.3 nmol/kg), the discharge rate of 47 out of 78 units increased markedly from 2.99+/-0.24 to 4.79+/-0.29 spikes/s (P<0.001), 20 units decreased from 3.24+/-0.46 to 1.97+/-0.37 spikes/s (P<0.001), and the remaining 11 showed no response. Blood pressure (BP) and heart rate (HR) did not change throughout the experimentation. (2) Pretreatment with intracarotid administration of calcitonin gene-related peptide receptor antagonist CGRP8-37 (3 nmol/kg) did not change the effects of AM. (3) Following intracarotid injection of NO precursor L-arginine (30 mg/kg), the excitatory effect of AM was attenuated. The above results indicate that AM can excite spontaneous electrical activity of AP neurons, this effect is not mediated by calcitonin gene-related peptide receptor but may be attenuated by NO precursor L-arginine.
authors.affiliation: Department of Physiology, Hebei Medical University, Shijazhuang 050017.
authors.forename: Shu-Mei
authors.initials: SM
authors.lastname: Ji
authors.forename: Hua
authors.initials: H
authors.lastname: Yue
authors.forename: Rui-Rong
authors.initials: RR
authors.lastname: He
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D053607:Adrenomedullin / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000294:innervation* / Q000502:physiology / Q000601:surgery; D031608:Area Postrema / Q000502:physiology*; D002346:Carotid Sinus / Q000294:innervation* / Q000502:physiology / Q000601:surgery; D003714:Denervation; D007269:Injections, Intra-Arterial; D008297:Male; D009474:Neurons / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D053607:Adrenomedullin