Effect of intracarotid administration of adrenomedullin on the spontaneous electrical activity of area postrema neurons in sino-aortic denervated rats.
- Author:
Shu-Mei JI
1
;
Hua YUE
;
Rui-Rong HE
Author Information
1. Department of Physiology, Hebei Medical University, Shijazhuang 050017.
- Publication Type:Journal Article
- MeSH:
Action Potentials;
physiology;
Adrenomedullin;
pharmacology;
Animals;
Aorta;
innervation;
physiology;
surgery;
Area Postrema;
physiology;
Carotid Sinus;
innervation;
physiology;
surgery;
Denervation;
Injections, Intra-Arterial;
Male;
Neurons;
physiology;
Rats;
Rats, Sprague-Dawley
- From:
Acta Physiologica Sinica
2003;55(4):395-400
- CountryChina
- Language:English
-
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.
