Aortic depressor nerve unmyelinated fibers in spontaneously hypertensive rats.
- 1 April 2001
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Heart and Circulatory Physiology
- Vol. 280 (4) , H1560-H1564
- https://doi.org/10.1152/ajpheart.2001.280.4.h1560
Abstract
The objective of the present study was to compare the morphology of the unmyelinated fibers in the aortic depressor nerves (ADN) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). In anesthetized rats, the ADN was identified by its spontaneous activity synchronous with the arterial pulses. Thin sections of the proximal and distal segments of the ADN were analyzed by electron microscopy, and a morphometric study of the unmyelinated fibers and Schwann cells was performed. The proximal segments of WKY and SHR ADN contain an average of 335 +/- 68 and 130 +/- 14 unmyelinated fibers, respectively (P < 0.05), and the distal segments contain an average of 337 +/- 46 and 242 +/- 77 unmyelinated fibers, respectively (P < 0.05). The distribution of the diameters of unmyelinated fibers was unimodal for both strains, with the histogram from the SHR significantly shifted to the left. Because the unmyelinated fibers play a role in the tonic inhibition of the medullary vasomotor centers, especially in the presence of hypertension, the morphological differences observed in the ADN from SHR may account, at least in part, for the blunted baroreflex of SHR.Keywords
This publication has 23 references indexed in Scilit:
- A Descriptive and Quantitative Light and Electron Microscopy Study of the Aortic Depressor Nerve in Normotensive RatsHypertension, 1997
- ALTERATION OF BARORECEPTOR AND CHEMORECEPTOR REFLEXES IN SPONTANEOUSLY HYPERTENSIVE RATSClinical and Experimental Pharmacology and Physiology, 1995
- Genealogy of the Spontaneously Hypertensive Rat and Wistar-Kyoto Rat StrainsJournal of Cardiovascular Pharmacology, 1990
- Biological variability in Wistar-Kyoto rats. Implications for research with the spontaneously hypertensive rat.Hypertension, 1987
- Central resetting of baroreflex in the spontaneously hypertensive rat.Hypertension, 1983
- Arterial baroreceptor reflex control of sympathetic nerve activity in the spontaneously hypertensive rat.Hypertension, 1979
- Structure of rat aortic baroreceptors and their relationship to connective tissueJournal of Neurocytology, 1979
- Modified Characteristics of the Aortic Baroreceptor Activities in the Spontaneously Hypertensive RatJapanese Circulation Journal, 1970
- The normal sural nerve in manActa Neuropathologica, 1969