Changes of neuronal nitric oxide synthase-immunopositive neurons in the central amygdaloid nucleus of spontaneously hypertensive rats

Abstract

Abstract: Objective To observe the changes of neuronal nitric oxide synthase (nNOS)-immunopositive neurons in the central amygdaloid nucleus of spontaneously hypertensive rats (SHRs).Methods Thirty SHRs and 30 Wistar-Koyto rats (WKYs) were sacrificed at the ages of 90, 180, and 360 days respectively to observe the changes of nNOS-immunopositive neurons with ABC immunocytochemical assay.Results No significant changes were observed in the blood pressure of WKY rats at the specified time points, when SHRs maintained significantly higher blood pressures from 20.8±1.1 and 26.3±1.0 kPa (P<0.05), gradually increasing during the development of hypertension. The nNOS-immunopositive neurons in the central amygdaloid nucleus were of moderate sizes with long intersected nerve fibers. No significant changes were found in WKY rats. The number of the positive neurons decreased with age in SHRs, especially obvious at 360 days (P<0.05), which was significantly different from that in the WKYs (P<0.05).Conclusion The reduction of nNOS-immunopositive neurons in the central amygdaloid nucleus of SHRs might accelerate the development of hypertension by modulating the cardiovascular function and sensory transmission.

CLC Number:

R322.8

SHEN Wei-zai¹, GUO Guo-qing¹, YU Jing². Changes of neuronal nitric oxide synthase-immunopositive neurons in the central amygdaloid nucleus of spontaneously hypertensive rats[J]. Journal of Southern Medical University, 2004, 24(11): 1274-1277.

References

[1] Sanders BJ, Wirtz-Nole C, DeFord SM, et al. Central amygdaloid lesions attenuate cardiovascular responses to acute stress in rats with borderline hypertension [J]. Physiol Behav, 1994, 56(4):709-13.
[2] 周初松,靳安民,马大烈.大鼠脊髓组织一氧化氮合酶显微及超微结构特征[J].第一军医大学学报,2000,20(6):485-7.Zhou CS Jin AM, Ma DL. Microscopic and ultrastructural features of nitric oxide synthase in rat spinal cord tissue [J]. J First Mil Med Univ/Di Yi Jun Yi Da Xue Xue Bao, 2000, 20(6):485-7.
[3] 郭志刚,沈剑刚,翁昌鸿,等.冠心病、高血压病人血浆氧自由基、一氧化氮及纤溶活性的变化[J].第一军医大学学报,1999,19(2):124-6.Guo ZG, Shen JG, Weng CH, et al. The changes of oxygen free radical, nitric oxide and fibrinolytic activity in plasma of the patients with coronary artery disease and hypertension [J]. J First Mil Med Univ/Di Yi Jun Yi Da Xue Xue Bao, 1999, 19(2):124-6.
[4] Galono T, Van Hoesen G, Maixner W, et al. Contribution of the amygdala to the development of spontaneous hypertension [J].Brain Res, 1982, 246(1):1-6.
[5] Reis D, Ledoux J. Some central neural mechanisms governing resting and behaviorally coupled control of blood pressure [J]. Circulation, 1987, 76(1 Pt 2):12-9.
[6] 叶季鲜,黄静,李红梅,等.高血压患者血浆一氧化氮浓度变化及其意义[J].西北国防医学杂志,2000,21(3):190-1.Ye JX, Huang J, Li HM, et al. Changes of nitric oxide concentration in plasma of essential hypertention and its significance [J]. Xibei Guofang Yixue Zazhi, 2000, 21(3):190-1.
[7] Okere CO, Kaba H, Higuchi T. Importance of endogenous nitric oxide synthase in the rat hypothalamus and amygdala in mediating the response to capsaicin[J]. J Comp Neurol, 2000, 423(4):670-86.
[8] Watson RE, Supowit SC, Zhao H, et al. Role of sensory nervous system vasoactive peptides in hypertension [J]. Braz J Med Biol Res,2002,35(9):1033-45.
[9] Zamir N, Shuber E. Altered pain perception in hypertensive humans[J]. Brain Res, 1980, 201(2):471-4.
[10] Wang DH, Li J, Qiu J. Salt-sensitive hypertension induced by sensory denervation:introduction of a new model [J]. Hypertension,1998, 32(4):649-53.
[11] Williams P, Gray H, Bannister L, et al. ChiefEditor. 杨琳, 高英茂,主译.格氏解剖学(Gray’s Anatomy)[M].沈阳:辽宁教育出版社,1999,第38版,p1134-5.
[12] Zardetto-Smith AM, Gray TS. Organization ofpeptidergic and catecholaminergic efferents from the nucleus of the solitary tract to the rat amygdala[J]. Brain Res Bull, 1990, 25(6):875-87.
[13] Csillik B, Nemcsok J, Boncz I, et al. Nitric oxide synthase and the acetylcholine receptor in the prefrontal cortex:metasynaptic organization of the brain[J]. Neurobiology, 1998, 6(4):383-404.
[14] Soderstrom V, Hylland P, Nilsson G E. Nitric oxide synthase inhibitor blocks acetylcholine induced increase in brain blood flow in rainbowtrout[J].Neurosci Lett,1995,197(3):191-4.