Modulation by angiotensin III of nociception-related and arterial pressure-related neuronal responsiveness in the nucleus reticularis gigantocellularis of the rat

Julie Y.H. Chan, Hsing Fei Tsai, Terry B.J. Kuo, Samuel H.H. Chan

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We evaluated possible modulation by angiotensin III (AIII) of the interactive effect of noxious stimuli and elevation in systemic arterial pressure on the responsiveness of neurons in the nucleus reticularis gigantocellularis (NRGC) of the medulla oblongata. Combined extracellular single-neuron recording and microiontophoresis were carried out on male, adult Sprague-Dawley rats anesthetized with pentobarbital sodium. The responsiveness of NRGC neurons to nociception (tail clamp) and/or transient hypertension elicited by phenylephrine (5 μg/kg, i.v.), in the absence or presence of AIII, was used as the experimental index. Microiontophoretic application of the heptapeptide suppressed the responses of spontaneously active NRGC neurons to individually delivered nociception or hypertension. Interestingly, the preferential reduction in responsiveness to tail clamp upon simultaneous elevation in arterial pressure was reversed to one that favored nociception in the presence of AIII. These actions of the heptapeptide appeared to be receptor-specific, since they were discernibly blocked by its selective antagonist, Ile7-angiotensin III. Our results reveal that neuropeptides such as AIII may differentially modulate neuronal responsiveness according to the prevailing physiologic input(s) to the central nervous system of the animal.

Original languageEnglish
Pages (from-to)247-257
Number of pages11
JournalRegulatory Peptides
Volume50
Issue number3
DOIs
Publication statusPublished - Mar 17 1994
Externally publishedYes

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Keywords

  • Angiotensin III
  • Arterial pressure-related neuron
  • Neuromodulation
  • Nociception-related neuron
  • Nucleus reticularis gigantocellularis
  • Rat

ASJC Scopus subject areas

  • Physiology
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Cellular and Molecular Neuroscience

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