Role of the Nitrergic System of the Cuneiform Nucleus in Cardiovascular Responses in Urethane-Anesthetized Male Rats

Iranian Journal of Medical Sciences

Mahmoud Hosseini¹  Abolfazl Khajavirad³  Esmaeil Farrokhi³  Ali Reza Ebrahimzadeh Bideskan⁴  Mohammad Naser Shafei⁵ 

[1] and Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran;Department of Anatomy and Cellular Biology, Mashhad University of Medical Sciences, Mashhad, Iran;Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran;Neurocognetive Research Center, Mashhad University of Medical Sciences, Mashhad, Iran;Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

关键词: Cuneiform nucleus;    Nitroprusside;    Nitric oxide;    Blood pressure;    NG-nitro-L-arginine methyl ester;   

DOI  :  

学科分类：基础医学

来源: Shiraz University of Medical Sciences

【 摘 要 】

Background: The presence of nitric oxide (NO) in the cuneiform nucleus (CnF) has been previously shown. In this study, NG-nitro-L-arginine methyl ester (L-NAME) (an inhibitor of NO synthase), L-arginine (L-Arg) (a precursor of NO), and sodium nitroprusside (SNP) (a donor of NO) were microinjected into the CnF and cardiovascular responses were investigated. Methods: Seventy male rats were divided into 7 groups (n=10 each): 1) saline, 2 and 3) L-NAME (30 and 90 nmol), 4 and 5) L-Arg (20 and 60 nmol), and 6 and 7) SNP (9 and 27 nmol). After anesthesia, the femoral artery was cannulated and cardiovascular parameters were recorded using a PowerLab system. Time course changes in mean arterial pressure (ΔMAP) and heart rate (ΔHR) were calculated and compared with those in the control group (repeated measures ANOVA). Maximum ∆MAP and ∆HR were also compared with those in the control group (independent sample t test). Results: ∆MAP with both doses of L-NAME (30: P=0.026 and 90: P=0.007) and ∆HR with the higher dose (P=0.034) were significantly higher than those in the control group. Maximal ∆MAP with both doses (P<0.01 and P<0.001, n=10) and maximal ∆HR with the higher dose (P<0.01) were significantly higher than those in the control group. Changes in L-Arg with both doses were not significantly higher than those in the control group (P=0.26, n=8). ∆MAP and ∆HR of SNP only with the higher dose were significantly lower than those in the control group (P=0.006 and P=0.035), and maximal responses with the higher dose were lower than those in the control group (∆MAP: P<0.01 and ∆HR: P<0.05, n=7). Conclusion: Our results showed that the nitrergic system of the CnF had an inhibitory effect on central cardiovascular regulation.

【 授权许可】

CC BY