scholarly journals Differential Responses to Blood Pressure and Oxidative Stress in Streptozotocin-Induced Diabetic Wistar-Kyoto Rats and Spontaneously Hypertensive Rats: Effects of Antioxidant (Honey) Treatment

2011 ◽  
Vol 12 (3) ◽  
pp. 1888-1907 ◽  
Author(s):  
Omotayo O. Erejuwa ◽  
Siti A. Sulaiman ◽  
Mohd Suhaimi Ab Wahab ◽  
Kuttulebbai N. S. Sirajudeen ◽  
Md Salzihan Md Salleh ◽  
...  
1995 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Naoyoshi Minami ◽  
Yutaka Imai ◽  
Jun-Ichiro Hashimoto ◽  
Keishi Abe

1. The aim of this study was to clarify the extent to which vascular nitric oxide contributes to basal blood pressure in conscious spontaneously hypertensive rats and normotensive Wistar Kyoto rats. 2. The contribution of vascular nitric oxide to maintenance of blood pressure was estimated by measuring the pressor response to an intravenous injection of nitric oxide synthase inhibitor, Nω-l-arginine methyl ester, given after serial injections of captopril, vasopressin V1-receptor antagonist (V1-antagonist) and ganglion blocker (pentolinium) in conscious spontaneously hypertensive and Wistar Kyoto rats aged 20–28 weeks. To estimate the ‘amplifier property’ of hypertrophied vasculature in spontaneously hypertensive rats, which is known to modulate pressor responses, the lower blood pressure plateau after serial injections of captopril, V1-antagonist and pentolinium and the maximum blood pressure elicited by subsequent injection of increasing doses of phenylephrine were also measured. 3. The serial injections of captopril, V1-antagonist and pentolinium decreased mean arterial pressure from 164 ± 9 mmHg to 67 ± 2 mmHg and from 117 ± 2 mmHg to 49 ± 1 mmHg in spontaneously hypertensive and Wistar Kyoto rats respectively. The subsequent injection of Nω-l-arginine methyl ester restored mean arterial pressure almost to its control levels in both spontaneously hypertensive and Wistar Kyoto rats. The absolute changes in mean arterial pressure elicited by Nω-l-arginine methyl ester were significantly greater in spontaneously hypertensive than in Wistar Kyoto rats (P < 0.01), but there was no significant difference in the responses to Nω-l-arginine methyl ester when they were expressed as percentages of either the lower blood pressure plateau or maximum blood pressure. 4. These results indicate that basal blood pressure in both spontaneous hypertensive and Wistar Kyoto rats is maintained by a balance between vascular nitric oxide and major pressor systems. They also suggest that the vasodilatory effect of vascular nitric oxide does not differ between spontaneously hypertensive and Wistar Kyoto rats, and that the increased pressor effect of Nω-l-arginine methyl ester in spontaneously hypertensive rats is due to a vascular amplifier mechanism.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Nithya Mariappan ◽  
Carrie Elks ◽  
Masudul Haque ◽  
Philip J Ebnezer ◽  
Elizabeth McIIwain ◽  
...  

The transcriptional factor, nuclear factor kappa B (NFkB) plays an important role in the regulation of cytokines. Among the cytokines, tumor necrosis factor-alpha (TNF) plays an important role in cardiovascular pathophysiology. This study was done to determine whether TNF-α blockade with etanercept (ETN) or NFkB blockade with dithiol pyrolidine thiocarbamate (PDTC) attenuate oxidative stress in the paraventricular nucleus (PVN) and contribute to neurohumoral excitation in spontaneously hypertensive rats. Method: Male 20 week old SHR rats were treated with ETN (1 mg/kg BW, sc) or PDTC (100mg/kg BW, ip) for 5 week period. Left ventricular function was measured at baseline (20 weeks) and at 25 weeks using echocardiography. Blood pressure was measured at weekly intervals throughout the study. At the end of the protocol rats were sacrificed the PVN was microdissected for the measurement of cytokines, oxidative stress markers using real time PCR (fold increase compared to WKY controls) and by immunohistochemistry. Superoxide, total reactive oxygen species and peroxynitrite were measured in the PVN and LV using electron paramagnetic resonance. Plasma norepinephrine and epinephrine an indicator of neurohumoral excitation was measured using HPLC-EC. Results: PVN data are tabulated. SHR animals had increased expression of protein and mRNA for cytokines and oxidative stress markers in the PVN and LV with increased MAP and cardiac hypertrophy when compared to WKY rats. Treatment with ETN and PDTC attenuated these increases with PDTC showing marked effect than ETN on hypertrophy and blood pressure responses. Conclusion: These findings suggest that cytokine activation in the PVN contributes to increased oxidative stress and neurohumoral excitation in hypertension.


2014 ◽  
Vol 8 (S4) ◽  
Author(s):  
Naiane Ferraz Bandeira Alves ◽  
Naiane Alves ◽  
Suênia Porpino ◽  
Matheus Monteiro ◽  
Thyago Queiroz ◽  
...  

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