Journal article
Effects of anti hypertensive drugs on capillary rarefaction in spontaneously hypertensive rats: intravital Microscopy and histologic analysis
Journal of cardiovascular pharmacology, Vol.51(4), pp.402-409
04/01/2008
DOI: 10.1097/FJC.0b013e3181673bc5
PMID: 18427284
Abstract
We investigated the effects of chronic oral antihyperiensive 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 +/- 17 and SHR 258 +/- 13 capillaries/mm(2), p < 0.01) and ear skin (WKY 391 +/- 18 and SHR 210 15 capillaries/mm(2), 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 +/- 0.08 and SHR 1.40 +/- 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 +/- 0.09 and SHR 0.42 +/- 0.09, P < 0.01). The animals were treated with the angiotensin-converting enzyme (ACE) inhibitor enalapril, the angiotensin II type I receptor (AT(1)) receptor antagonist losartan, the P-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 antihyper-tensive drugs with similar effect on blood pressure differ in terms of their effect on the microcirculation.
Details
- Title: Subtitle
- Effects of anti hypertensive drugs on capillary rarefaction in spontaneously hypertensive rats: intravital Microscopy and histologic analysis
- Creators
- Bruno Sabino - Fundação Oswaldo CruzMarcos A. Lessa - University of Iowa, AnesthesiaAlessandro R. Nascimento - Fundação Oswaldo CruzCarlos A. B. Rodrigues - Inst Drug Technol, Dept Appl Pharmacol, Rio De Janeiro, BrazilMaria das Graas Henriques - Inst Drug Technol, Dept Appl Pharmacol, Rio De Janeiro, BrazilLuciana R. Garzoni - Fundação Oswaldo CruzBernard I. Levy - Hôpital LariboisièreEduardo Tibirica - Fundação Oswaldo Cruz
- Resource Type
- Journal article
- Publication Details
- Journal of cardiovascular pharmacology, Vol.51(4), pp.402-409
- DOI
- 10.1097/FJC.0b013e3181673bc5
- PMID
- 18427284
- NLM abbreviation
- J Cardiovasc Pharmacol
- ISSN
- 0160-2446
- eISSN
- 1533-4023
- Publisher
- Lippincott Williams & Wilkins
- Number of pages
- 8
- Language
- English
- Date published
- 04/01/2008
- Academic Unit
- Anesthesia
- Record Identifier
- 9984656534002771
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