Effect of hypothalamic nerve growth factor precursor on field potential of paraventrucular nucleus during rat cardiopulmonary bypass / 临床麻醉学杂志

ABSTRACT

Objective To evaluate the effect of cardiopulmonary bypass (CPB) on the expression of hypothalamic nerve growth factor precursor (proNGF) and the influence of hypothalamic proNGF on the sympathetic output of paraventrucular nucleus. Methods Forty-two male SD rats, aged 3-4 months, weighing 350-500 g, were divided into control group, CPB group and ischemia reperfusion (IR) group. At the end of CPB for 110 min, hypothalamus and dorsal root ganglion (DRG) were taken to measure the levels of proNGF mRNA and hypothalamic proNGF protein. Mini pipe was put into bilateral paraventrucular nucleus (PVN) and human recombination proNGF protein was injected into PVN for 7 d before the local field potentials (LFP) of RVLM was recoreded. Human recombination proNGF protein was administrated into lateral ventricle, the prior-administration-LFP of PVN and post-administration-LFP were recorded and compared. At the end of the experiment, hypothalamus was taken to measure the levels of glutamate and gammer amino butyric acid (GABA). Results Hypothalamic proNGF protein in CPB group and IR group was higher than that in the control group (P ＜ 0.05); NGF mRNA of hypothalamus and DRG in CPB and IR group were higher than those of control group (P ＜ 0.05). In PVN and RVLM, after the administration of proNGF protein, the power of delta band significantly decreased and other bands increased (P ＜ 0.05). The hypothalamic GABA level decreased (P ＜ 0.05) with no change of hypothalamic glutamate after proNGF was injected into lateral ventricle. Conclusion CPB increases the expression of proNGF in the hypothalamus contributing to the changes of hypothalamic sympathetic output.