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Impairment of pressure-natriuresis and renal autoregulation in ANG II-infused hypertensive rats.
Am J Physiol Renal Physiol. 2000 Aug; 279(2):F319-25.AJ

Abstract

Chronic infusions of initially subpressor doses of angiotensin II (ANG II) lead to progressive hypertension over a 2-wk period and to augmented intrarenal ANG II levels. The present study was performed to investigate total renal blood flow (RBF) and medullary blood flow (MBF) autoregulatory behavior and pressure-natriuresis in ANG II-infused hypertensive rats and how these are modified by concomitant treatment with an ANG II AT(1) receptor antagonist. ANG II-infused rats (n = 27) were prepared by administration of ANG II at 60 ng/min via osmotic minipump for 13 days. Twelve of the ANG II-infused hypertensive rats were treated with losartan in the drinking water (30 mg. kg.(-1) day(-1)). Rats were anesthetized with pentobarbital sodium (50 mg/kg, ip) and prepared for renal function measurements. An aortic clamp was placed above the junction of the left renal artery to reduce renal arterial pressure. Autoregulatory responses for renal plasma flow, overall RBF, and glomerular filtration rate were impaired in ANG II-infused hypertensive rats; however, MBF autoregulation was not disrupted. Most strikingly, pressure-natriuresis was markedly suppressed in ANG II-infused hypertensive rats. Chronic treatment with losartan prevented the impairment of the pressure-natriuresis relationship caused by chronic ANG II infusion. These findings demonstrate that chronic ANG II infusion leads to marked impairment of sodium excretion and suppression of the pressure-natriuresis relationship, which may contribute to the progressive hypertension that occurs in this model. These renal effects are prevented by simultaneous treatment with an AT(1) receptor blocker.

Authors+Show Affiliations

Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, USA.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

10919852

Citation

Wang, C T., et al. "Impairment of Pressure-natriuresis and Renal Autoregulation in ANG II-infused Hypertensive Rats." American Journal of Physiology. Renal Physiology, vol. 279, no. 2, 2000, pp. F319-25.
Wang CT, Chin SY, Navar LG. Impairment of pressure-natriuresis and renal autoregulation in ANG II-infused hypertensive rats. Am J Physiol Renal Physiol. 2000;279(2):F319-25.
Wang, C. T., Chin, S. Y., & Navar, L. G. (2000). Impairment of pressure-natriuresis and renal autoregulation in ANG II-infused hypertensive rats. American Journal of Physiology. Renal Physiology, 279(2), F319-25.
Wang CT, Chin SY, Navar LG. Impairment of Pressure-natriuresis and Renal Autoregulation in ANG II-infused Hypertensive Rats. Am J Physiol Renal Physiol. 2000;279(2):F319-25. PubMed PMID: 10919852.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Impairment of pressure-natriuresis and renal autoregulation in ANG II-infused hypertensive rats. AU - Wang,C T, AU - Chin,S Y, AU - Navar,L G, PY - 2000/8/5/pubmed PY - 2000/9/19/medline PY - 2000/8/5/entrez SP - F319 EP - 25 JF - American journal of physiology. Renal physiology JO - Am. J. Physiol. Renal Physiol. VL - 279 IS - 2 N2 - Chronic infusions of initially subpressor doses of angiotensin II (ANG II) lead to progressive hypertension over a 2-wk period and to augmented intrarenal ANG II levels. The present study was performed to investigate total renal blood flow (RBF) and medullary blood flow (MBF) autoregulatory behavior and pressure-natriuresis in ANG II-infused hypertensive rats and how these are modified by concomitant treatment with an ANG II AT(1) receptor antagonist. ANG II-infused rats (n = 27) were prepared by administration of ANG II at 60 ng/min via osmotic minipump for 13 days. Twelve of the ANG II-infused hypertensive rats were treated with losartan in the drinking water (30 mg. kg.(-1) day(-1)). Rats were anesthetized with pentobarbital sodium (50 mg/kg, ip) and prepared for renal function measurements. An aortic clamp was placed above the junction of the left renal artery to reduce renal arterial pressure. Autoregulatory responses for renal plasma flow, overall RBF, and glomerular filtration rate were impaired in ANG II-infused hypertensive rats; however, MBF autoregulation was not disrupted. Most strikingly, pressure-natriuresis was markedly suppressed in ANG II-infused hypertensive rats. Chronic treatment with losartan prevented the impairment of the pressure-natriuresis relationship caused by chronic ANG II infusion. These findings demonstrate that chronic ANG II infusion leads to marked impairment of sodium excretion and suppression of the pressure-natriuresis relationship, which may contribute to the progressive hypertension that occurs in this model. These renal effects are prevented by simultaneous treatment with an AT(1) receptor blocker. SN - 1931-857X UR - https://www.unboundmedicine.com/medline/citation/10919852/Impairment_of_pressure_natriuresis_and_renal_autoregulation_in_ANG_II_infused_hypertensive_rats_ L2 - http://journals.physiology.org/doi/full/10.1152/ajprenal.2000.279.2.F319?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -