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Atrial natriuretic peptide blunts arterial baroreflex in spontaneously hypertensive rats.
Hypertension. 1996 Feb; 27(2):297-302.H

Abstract

We and other laboratories have reported that arterial baroreflex-mediated control of heart rate is blunted in spontaneously hypertensive rats (SHR) compared with normotensive controls. Recently, we reported that atrial natriuretic peptide (ANP) microinjected into the caudal nucleus tractus solitarii of SHR further blunts this defect. The present study tested the hypothesis that ANP modulates arterial baroreflex-mediated control of sympathetic nervous system activity. Nine-week-old, male SHR (n = 29) and normotensive Wistar-Kyoto control rats (n = 24) were instrumented for microinjection into the caudal nucleus tractus solitarii and for direct measurement of arterial blood pressure, heart rate, and lumbar sympathetic nervous system activity. After urethane- and alpha-chloralose-induced induced anesthesia, arterial baroreflex-mediated control of heart rate and lumbar sympathetic nerve activity was assessed during phenylephrine- (5 to 40 micrograms.kg-1.min-1) induced increases and sodium nitroprusside- (15 to 300 micrograms.kg-1.min-1) induced decreases in mean blood pressure before and after microinjection of ANP (50 ng) or monoclonal antibody to ANP (0.55 micrograms) into the caudal nucleus tractus solitarii. ANP reduced and the antibody enhanced the sensitivity of baroreflex-mediated control of both heart rate and lumbar sympathetic nerve activity in SHR but not in Wistar-Kyoto controls (P < .05). Arterial baroreflex sensitivity was unchanged with control microinjections of vehicle or mouse IgG in SHR. These data suggest that endogenous ANP in the caudal nucleus tractus solitarii may contribute to the development and/or maintenance of hypertension in SHR by blunting baroreflex-mediated control of sympathetic nervous system activity.

Authors+Show Affiliations

Department of Medicine, University of Alabama at Birmingham 35294-0007, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8567055

Citation

Zhu, S T., et al. "Atrial Natriuretic Peptide Blunts Arterial Baroreflex in Spontaneously Hypertensive Rats." Hypertension (Dallas, Tex. : 1979), vol. 27, no. 2, 1996, pp. 297-302.
Zhu ST, Chen YF, Wyss JM, et al. Atrial natriuretic peptide blunts arterial baroreflex in spontaneously hypertensive rats. Hypertension. 1996;27(2):297-302.
Zhu, S. T., Chen, Y. F., Wyss, J. M., Nakao, K., Imura, H., Oparil, S., & Calhoun, D. A. (1996). Atrial natriuretic peptide blunts arterial baroreflex in spontaneously hypertensive rats. Hypertension (Dallas, Tex. : 1979), 27(2), 297-302.
Zhu ST, et al. Atrial Natriuretic Peptide Blunts Arterial Baroreflex in Spontaneously Hypertensive Rats. Hypertension. 1996;27(2):297-302. PubMed PMID: 8567055.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Atrial natriuretic peptide blunts arterial baroreflex in spontaneously hypertensive rats. AU - Zhu,S T, AU - Chen,Y F, AU - Wyss,J M, AU - Nakao,K, AU - Imura,H, AU - Oparil,S, AU - Calhoun,D A, PY - 1996/2/1/pubmed PY - 1996/2/1/medline PY - 1996/2/1/entrez SP - 297 EP - 302 JF - Hypertension (Dallas, Tex. : 1979) JO - Hypertension VL - 27 IS - 2 N2 - We and other laboratories have reported that arterial baroreflex-mediated control of heart rate is blunted in spontaneously hypertensive rats (SHR) compared with normotensive controls. Recently, we reported that atrial natriuretic peptide (ANP) microinjected into the caudal nucleus tractus solitarii of SHR further blunts this defect. The present study tested the hypothesis that ANP modulates arterial baroreflex-mediated control of sympathetic nervous system activity. Nine-week-old, male SHR (n = 29) and normotensive Wistar-Kyoto control rats (n = 24) were instrumented for microinjection into the caudal nucleus tractus solitarii and for direct measurement of arterial blood pressure, heart rate, and lumbar sympathetic nervous system activity. After urethane- and alpha-chloralose-induced induced anesthesia, arterial baroreflex-mediated control of heart rate and lumbar sympathetic nerve activity was assessed during phenylephrine- (5 to 40 micrograms.kg-1.min-1) induced increases and sodium nitroprusside- (15 to 300 micrograms.kg-1.min-1) induced decreases in mean blood pressure before and after microinjection of ANP (50 ng) or monoclonal antibody to ANP (0.55 micrograms) into the caudal nucleus tractus solitarii. ANP reduced and the antibody enhanced the sensitivity of baroreflex-mediated control of both heart rate and lumbar sympathetic nerve activity in SHR but not in Wistar-Kyoto controls (P < .05). Arterial baroreflex sensitivity was unchanged with control microinjections of vehicle or mouse IgG in SHR. These data suggest that endogenous ANP in the caudal nucleus tractus solitarii may contribute to the development and/or maintenance of hypertension in SHR by blunting baroreflex-mediated control of sympathetic nervous system activity. SN - 0194-911X UR - https://www.unboundmedicine.com/medline/citation/8567055/Atrial_natriuretic_peptide_blunts_arterial_baroreflex_in_spontaneously_hypertensive_rats_ L2 - http://www.ahajournals.org/doi/full/10.1161/01.hyp.27.2.297?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -