Acetylcholine and bradykinin enhance hypotension and affect the function of remodeled conduit arteries in SHR and SHR treated with nitric oxide donors

Brazilian Journal of Medical and Biological Research

M. Gerová¹  F. Kristek¹  S. Cacányiová¹  M. Cebová¹ 

[1] ,Academy of Sciences Institute of Normal and Pathological Physiology Bratislava,Slovakia

关键词: Hypertension;    Conduit iliac artery;    Resistance arteries;    Molsidomine;    Pentaerythritol tetranitrate;    Iliac artery;    Structure;   

DOI  :  10.1590/S0100-879X2005000600019

来源: SciELO

【 摘 要 】

Discrepancy was found between enhanced hypotension and attenuated relaxation of conduit arteries in response to acetylcholine (ACh) and bradykinin (BK) in nitric oxide (NO)-deficient hypertension. The question is whether a similar phenomenon occurs in spontaneously hypertensive rats (SHR) with a different pathogenesis. Wistar rats, SHR, and SHR treated with NO donors [molsidomine (50 mg/kg) or pentaerythritol tetranitrate (100 mg/kg), twice a day, by gavage] were studied. After 6 weeks of treatment systolic blood pressure (BP) was increased significantly in experimental groups. Under anesthesia, the carotid artery was cannulated for BP recording and the jugular vein for drug administration. The iliac artery was used for in vitro studies and determination of geometry. Compared to control, SHR showed a significantly enhanced (P < 0.01) hypotensive response to ACh (1 and 10 µg, 87.9 ± 6.9 and 108.1 ± 5.1 vs 35.9 ± 4.7 and 64.0 ± 3.3 mmHg), and BK (100 µg, 106.7 ± 8.3 vs 53.3 ± 5.2 mmHg). SHR receiving NO donors yielded similar results. In contrast, maximum relaxation of the iliac artery in response to ACh was attenuated in SHR (12.1 ± 3.6 vs 74.2 ± 8.6% in controls, P < 0.01). Iliac artery inner diameter also increased (680 ± 46 vs 828 ± 28 µm in controls, P < 0.01). Wall thickness, wall cross-section area, wall thickness/inner diameter ratio increased significantly (P < 0.01). No differences were found in this respect among SHR and SHR treated with NO donors. These findings demonstrated enhanced hypotension and attenuated relaxation of the conduit artery in response to NO activators in SHR and in SHR treated with NO donors, a response similar to that found in NO-deficient hypertension.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License