Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/32178
Title: Effects of Antihypertensive Drugs on Capillary Rarefaction in Spontaneously Hypertensive Rats: Intravital Microscopy and Histologic Analysis
Authors: Sabino, Bruno
Lessa, Marcos A.
Nascimento, Alessandro R.
Rodrigues, Carlos A. B.
Henriques, Maria das Graças
Garzoni, Luciana R.
Levy, Bernard I.
Tibiriçá, Eduardo
Affilliation: Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Farmacologia Neuro-Cardiovascular. Rio de Janeiro, RJ. Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Farmacologia Neuro-Cardiovascular. Rio de Janeiro, RJ. Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Farmacologia Neuro-Cardiovascular. Rio de Janeiro, RJ. Brasil.
Instituto de Tecnologia de Drogas. Departamento de Farmacologia Aplicada. Rio de Janeiro, RJ, Brasil.
Instituto de Tecnologia de Drogas. Departamento de Farmacologia Aplicada. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Farmacologia Neuro-Cardiovascular. Rio de Janeiro, RJ. Brasil.
Hópital Lariboisiére. Cardiovascular Research Center. Paris, France.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Farmacologia Neuro-Cardiovascular. Rio de Janeiro, RJ. Brasil.
Abstract: We investigated the effects of chronic oral antihypertensive treatment on functional and structural capillary rarefaction in spontaneously hypertensive rats (SHR). Wistar Kyoto rats (WKY) were used as a normotensive control group. In untreated rats, intravital videomicroscopy showed that functional capillary density was lower in SHR skeletal muscle (WKY 395 6 17 and SHR 258 6 13 capillaries/mm2, P , 0.01) and ear skin (WKY 391 6 18 and SHR 210 6 15 capillaries/mm2, P , 0.01). A linear relationship was seen between skeletal muscle and skin capillary densities (r = 0.654, P , 0.0001). Histologic analysis showed that SHR had a lower capillaryto- fiber ratio in the skeletal muscle (WKY 1.74 6 0.08 and SHR 1.40 6 0.06, P , 0.01). Capillary volume density-to-fiber volume density ratio in the left ventricle of SHR was also reduced (WKY 0.55 6 0.09 and SHR 0.42 6 0.09, P , 0.01). The animals were treated with the angiotensin-converting enzyme (ACE) inhibitor enalapril, the angiotensin II type I receptor (AT1) receptor antagonist losartan, the b-blocker atenolol, or the calcium channel blocker nifedipine, resulting in similar reductions in systolic blood pressure (19.8%, 19.1%, 17.4%, and 18.2%, respectively, P . 0.05). Atenolol did not induce any change in functional capillary density of SHR. Losartan and nifedipine completely reversed functional capillary rarefaction in both muscle and cutaneous tissues, whereas enalapril significantly increased functional capillary density only in the skin. The skeletal muscle capillary-to-fiber ratio was normalized by enalapril, losartan, and nifedipine. Treatments with enalapril or losartan normalized the cardiac structural capillary rarefaction of SHRs, whereas atenolol and nifedipine had no effect. Our results suggest that different pharmacologic classes of antihypertensive drugs with similar effect on blood pressure differ in terms of their effect on the microcirculation.
Keywords: Capillary rarefaction
Intravital capillaroscopy
SHR
AT1 receptor antagonist
b-blocker
ACE inhibitor
Calcium channel blocker
keywords: Bloqueador de canal de cálcio
Capilaroscopia intravital
Antagonista do receptor AT1
Hipertensão
DeCS: Ratos Endogâmicos SHR
Issue Date: 2008
Publisher: Lippincott, Williams & Wilkins
Citation: SABINO, Bruno et al. Effects of Antihypertensive Drugs on Capillary Rarefaction in Spontaneously Hypertensive Rats: Intravital Microscopy and Histologic Analysis. J. Cardiovasc. Pharmacol., v. 51, n. 4, Apr. 2008.
ISSN: 0160-2446
Copyright: restricted access
Appears in Collections:IOC - Artigos de Periódicos

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