Effect of intracarotid administration of adrenomedullin on the spontaneous electrical activity of area postrema neurons in sino-aortic denervated rats

( views:51, downloads:0 )
Journal Title:
Volume 55, Issue 04, 2003
Key Word:
adrenomedullin;area postrema;spontaneous single-units discharge;calcitonin gene-related peptide receptor antagonist;L-arginine

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.

  • [1]Owji AA, Smith DM, Coppock HA, Morgan DG, Bhogal R, Ghatei MA, Bloom SR. An abundant and specific binding site for the novel vasodilator adrenomedullin in the rat. Endocrinology 1995;136(5):2127-2134.
  • [2]Kitamura K, Kangawa K, Kawamoto M, Ichiki Y, Nakamura S, Matsuo H, Eto T. Adrenomedullin: a novel hypotensive peptide isolated from human pheochromocytoma. Biochem Biophys Res Commun 1993;192(2):553-560.
  • [3]Parkes DG. Cardiovascular actions of adrenomedullin in conscious sheep.Am J Physiol 1995;268(6 Pt 2):H2574-H2578.
  • [4]Takahashi H, Watanabe TX, Nishimura M, Nakanishi T, Sakamoto M, Yoshimura M, Komiyama Y, Masuda M, Murakami T. Centrally induced vasopressor and sympathetic responses to a novel endogenous peptide, adrenomedul-lin, in anesthetized rats. Am J Hypertens 1994;7(5):478-482.
  • [5]Saita M, Shimokawa A, Kunitake T, Kato K, Hanamori T, Kitamura K, Eto T, Kannan H. Central actions of adrenomedullin on cardiovascular parameters and sympathetic outflow in conscious rats. Am J Physiol 1998;274(4 Pt 2):R979-R984.
  • [6]Samson WK, Murphy TC, Resch ZT. Central mechanisms for the hypertensive effects of preproadrenomedullin-derived peptides in conscious rats. Am J Physiol 1998;274(5 Pt 2):R1505-R1509.
  • [7]Oliver KR, Wainwright A, Heavens RP, Hill RG, Sirinathsinghji DJ. Distribution of novel CGRP1 receptor and adrenomedullin receptor mRNAs in the rat central nervous system. Brain Res Mol Brain Res 1998;57(1):149-154.
  • [8]Shan J, Krukoff TL. Distribution of preproadrenomedullin mRNA in the rat central nervous system and its modulation by physiological stressors. J Comp Neurol 2001;432(1):88-100.
  • [9]Serrano J, Uttenthal LO, Martinez A, Fernandez AP, Martinez de Velasco J, Alonso D, Bentura ML, Santacana M, Gallardo JR, Martinez-Murillo R, Cuttitta F, Rodrigo J. Distribution of adrenomedullin-like immunoreactivity in the rat central nervous system by light and electron microscopy. Brain Res 2000;853(2):245-268.
  • [10]Shan J, Krukoff TL. Intracerebroventricular adrenomedul-lin stimulates the hypothalamic-pituitary-adrenal axis, the sympathetic nervous system and production of hypothalamic nitric oxide. J Neuroendocrinol 2001;13(11):975-984.
  • [11]Takahashi K. Adrenomedullin from a pheochromocytoma to the eye: implications of the adrenomedullin research for endocrinology in the 21st century. Tohoku J Exp Med 2001;193(2):79-114.
  • [12]Chen S, He RR. Effect of intracarotid administration of adenosine on the activity of area postrema neurons in barodenervated rats. Acta Physiol Sin 1999;51(6):667-674.
  • [13]Papas S, Smith P, Ferguson AV. Electrophysiological evidence that systemic angiotensin influences rat area postrema neurons. Am J Physiol 1990;258(1 Pt 2):R70-R76.
  • [14]Hasser EM, Bishop VS. Reflex effect of vasopressin after blockade of V1 receptors in the area postrema. Circ Res 1990;67(2):265-271.
  • [15]Ferguson AV, Smith P. Circulating endothelin influences area postrema neurons. Regul Pept 1991;32(1):11-21.
  • [16]Li DP, He RR. Intracarotid injection of endothelin-1 facilitates the activity of rostral ventrolateral medullary neurons via area postrema in rats. Acta Physiol Sin 1999;51(3):263-271.
  • [17]Allen MA, Ferguson AV. In vitro recordings from area postrema neurons demonstrate responsiveness to adrenomedullin. Am J Physiol 1996;270(4 Pt 2):R920-R925.
  • [18]Allen MA, Smith PM, Ferguson AV. Adrenomedullin microinjection into the area postrema increases blood pressure. Am J Physiol 1997;272(6 Pt 2):R1698-R1703.
  • [19]Paxinos G, Watson C. The Rat Brain in Stereotaxic Coordinates.New York: Academic Press, 1982.
  • [20]Juaneda C, Dumont Y, Chabot JG, Quirion R. Autoradiographic distribution of adrenomedullin receptors in the rat brain. Eur J Pharmacol 2001;421(2):R1-R2.
  • [21]Sone M, Takahashi K, Satoh F, Murakami O, Totsune K, Ohneda M, Sasano H, Ito H, Mouri T. Specific adrenomedullin binding sites in the human brain. Peptides 1997;18(8):1125-1129.
  • [22]Yang LM (杨丽明), He RR. Effects of microinjection of L-NNA and SNP into ventrolateral medulla on blood pressure, heart rate and renal sympathetic nerve activity in rats. Acta Physiol Sin (生理学报) 1996; 48(4):368-376 (Chinese, English abstract).
  • [23]Xue BJ (薛保建), Wang ZA, He RR. Effects of NO precursor and donor on neuronal activity of rat hippocampal slices. Acta Physiol Sin (生理学报) 1997;49(4):375-381 (Chinese, English abstract).
WanfangData CO.,Ltd All Rights Reserved
About WanfangData | Contact US
Healthcare Department, Fuxing Road NO.15, Haidian District Beijing, 100038 P.R.China
Tel:+86-010-58882616 Fax:+86-010-58882615 Email:yiyao@wanfangdata.com.cn