Effect of Candida albicans septicemia on the cardiovascular function of rabbits.
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Department of Pharmacology/Clinical Pharmacology, Ankara University, School of Medicine, Sihhiye, Ankara 06100, Turkey.Abstract
Candida
albicans is an opportunistic pathogen that causes life-threatening
systemic infection in immunocompromised host. However, little is known
about the effects of yeast on the cardiovascular functions. This study
examined the effects of C. albicans septicemia on the heart and vessel
functions and nitric oxide (NO) production in infected rabbits.
Anaesthetized animals were challenged with intravenous C. albicans (6 x
10(8)/kg) or saline and the blood pressure of rabbits were measured over
5 h. After that response of the isolated thoracic aorta, right atrium
and left papillary muscle were recorded. Blood pressure significantly
decreased in the infected rabbits during the septicemia but in the
control animals it was stable. The blood nitrite levels and NO-synthases
(eNOS, iNOS) expression and tissue nitrite levels in the heart and
aorta were similar in the both groups. In the aorta isolated from C.
albicans-infected rabbits, acetylcholine-induced endothelium-dependent
relaxation was decreased, but contractions induced by phenylephrine were
potentiated. The NOS inhibitor, L-N(G)-nitro-arginine methyl ester
(L-NAME)-induced contraction increase in the right atrium was depressed
by the yeast-infection. In the heart and aorta, microscopic examination
revealed no tissue invasion of C. albicans. These results indicate the
ability of C. albicans-induced septicemia to destroy NO-related
responses of the heart and aorta and may have important implications for
functional damage to endothelium and the regulation of cardiovascular
functions. In addition, NOS induction and NO over-production are not
stimulated by systemic C. albicans infection, which would alter the host
immune reaction and homeostasis.
- PMID:
- 15778125
- [PubMed - indexed for MEDLINE]
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