Chronic selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in rats.
Cardiovasc Res
; 42(3): 783-93, 1999 Jun.
Article
en En
| MEDLINE
| ID: mdl-10533619
ABSTRACT
OBJECTIVE/METHODS:
In order to investigate whether selective hypertriglyceridemia impairs endothelium-dependent vasodilatation in the rat hindlimb, rats were selectively bred to establish two strains, one with a pronounced hypertriglyceridemia (HT) and the other with normal plasma levels of triglycerides (LT).RESULTS:
Carotid arteries and aortae removed from 3, 6, 9 and 12 month old LT- and HT-rats exhibited a normal morphology. However, marked morphological differences were observed between vessels from 18-20 month old HT- and LT-rats. The endothelium-dependent vasodilator acetylcholine (2 to 50 micrograms/kg), administered into the iliac artery, elicited a concentration-dependent increase in hindlimb blood flow which was not different in 3, 6 and 9 month old LT- or HT-rats but was impaired in 12 and 18-20 month old HT-rats. In contrast the endothelium-independent vasodilator sodium nitroprusside enhanced blood flow in both strains to a similar extent. Neither administration of the nitric oxide (NO) synthase (NOS) substrate, L-arginine, nor the NOS inhibitor NGnitro-L-arginine, affected the responsiveness to endothelium-dependent vasodilators in 12 month old HT-rats. These attenuated responses could not be attributed to a decrease in endothelial NOS expression as Western blot analysis revealed identical levels of this enzyme in the aortae and carotid arteries from LT- and HT-rats. Determination of superoxide anion (O2-) formation however, demonstrated a markedly elevated production of O2- in aortae from HT-rats.CONCLUSION:
We conclude that chronic selective hypertriglyceridemia, an independent risk factor in the development and progression of atherosclerosis, leads to an endothelial dysfunction which is associated with an increased vascular O2- production and a subsequent decrease in bioavailable NO.
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Banco de datos:
MEDLINE
Asunto principal:
Vasodilatación
/
Endotelio Vascular
/
Hipertrigliceridemia
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Año:
1999
Tipo del documento:
Article