Effects of Asphyxia on Arterial Blood Pressure, Formation of Nitric Oxide in Medulla and Blood Parameters in the Cat

Wun-Chin Wu ； Jinn-Pyng Ueng ； Chok-Yung Chai

《The Chinese Journal of Physiology》 48卷1期 (2005/03) Pp. 51-56

並列摘要

The rostral ventrolateral medulla (RVLM) plays an important role in the integration of cardiovascular functions. We examined the effect of asphyxia on cardiovascular responses, on sympathetic vertebral nerve activity (VNA) and nitric oxide (NO) formation in the RVLM, on hemodynamics, and on plasma concentrations of catecholamines, blood gas partial pressures and carbohydrate metabolites. Using 16 anesthetized cats we found that the systemic arterial pressure (SAP), VNA, NO formation and the release of plasma catecholamine components of norepinephrine and epinephrine were increased during asphyxia. The onset of NO production was significantly earlier than that of SAP and VNA. The venous partial pressure of O2 decreased, while the partial pressure of CO2 increased. Furthermore, metabolism of glucose and lactate increased, as did the blood concentrations of white and red blood cells, hemoglobin and platelets. Thus, asphyxia increased SAP, VNA and NO formation. It increased the plasma catecholamines, blood gases, carbohydrate metabolites and blood cells.

並列關鍵字

epinephrine ； glucose ； lactate ； hemoglobin ； nitric oxide ； norepinephrine

參考文獻

Beckman, J.S.(1991).The double-edge role of nitric oxide in brain function and superoxide-mediated injury.J. Dev. Physiol.15,53-59.

Bravo, F.L.,Tarazi, R.C.(1982).Plasma catecholamine in clinical practice: a useful index, a meaningless number?.J. Lab. Clin. Med..100,155-160.

Chai, C.Y.,Lin, R.H.,Lin, A.M.Y.,Pan, C.M.,Lee, E.H.Y.,Kuo, J.S.(1988).Pressor responses from electrical or glutamate stimulations of the dorsal or ventrolateral medulla.Am. J. Physiol..255,709-717.

Chai, C.Y.,Lin, A.M.Y.,Su, C.K.,Hu, S.R.,Yuan, C.,Kao, L.S.,Goldstein, D.S.(1991).Sympathoadrenal excitation and inhibition by lower brainstem stimulation in cats.J. Auton. Nerv. Syst..33,33-46.

Chan, R.K.W.,Sawchenko, P.E.(1998).Organization and transmitter specificity of medullary neurons activated by sustained hypertension: Implications for understanding baroreceptor reflex circuitry.J. Neurosci..18,371-387.