Increased NO bioavailability in aging male rats by genistein and exercise training: using 4, 5-diaminofluorescein diacetate

• Main Authors: Siriviriyakul Prasong (Author), Suksom Daroonwan (Author), Eksakulkla Sukanya (Author), Patumraj Suthiluk (Author)
• Format: Book
• Published: BMC, 2009-09-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<p>Abstract</p> <p>Background</p> <p>Several kinds of anti-oxidants have drawn a lot of intension for their benefits on vascular protection. In addition, it has been demonstrated that exercise training could improve endothelial function by up-regulating endothelial nitric oxide synthase (eNOS) protein. Therefore, the present study aims to investigate the effects of genistein, a potent phyto-antioxidant, and exercise training on age-induced endothelial dysfunction in relation to NO bioavailability using in situ NO-sensitive fluorescent dye detection.</p> <p>Methods</p> <p>Male Wistar rats (20-22-month old) were divided into four groups: aged rats treated with corn oil, (Aged+Veh, n = 5), aged rats treated with genistein (Aged+Gen, n = 5, (0.25 mg/kg BW/day, s.c.)), aged rats with and without exercise training (Aged+Ex, n = 5, swimming 40 min/day, 5 days/week for 8 weeks) (Aged+Without-Ex, n = 5). Cremaster arterioles (15-35 micrometer) were visualized by fluorescein isothiocyanate labeled dextran (5 microgram/ml). The vascular response to acetylcholine (Ach; 10^-5M, 5 ml/5 min) was accessed after 1-min norepinephrine preconstriction (10 micro molar). To determine NO bioavailability, the Krebs-Ringer buffer with 4, 5-diaminofluorescein-diacetate (3 micro molar DAF-2DA), and 10 micro- molar Ach saturated with 95%N₂and 5%CO₂were used. Changes of DAF-2T-intensities along the cremaster arterioles were analyzed by the Image Pro-Plus Software (Media Cybernatics, Inc, USA). Liver malondialdehyde (MDA) level was measured by thiobarbituric acid reaction and used as an indicator for oxidative stress.</p> <p>Results</p> <p>The results showed that means arterial blood pressure for both Aged+Gen and Aged+Ex groups were significantly reduced when compared to the Aged groups, Aged+Veh and Aged+Without-Ex (P < 0.05). Among the treated groups, Ach-induced vasodilatation were significantly increased (P < 0.05) and was associated with increased NO-associated fluorescent intensities (P < 0.05). On the other hand, MDA levels were significantly reduced (P < 0.05) when Aged+Veh was compared to Aged+Without-Ex.</p> <p>Conclusion</p> <p>These findings showed that genistein and exercise training could improve age-induced endothelial dysfunction and is related to the increased NO bioavailability.</p>

Item Description

10.1186/1477-7827-7-93
1477-7827