Collares-Buzato C B, Collares E F, Fernandes G A
Departamento de Fisiologia e Biofísica, Universidade Estadual de Campinas, SP, Brasil.
Braz J Med Biol Res. 1993 Sep;26(9):1009-14.
The effects of cold restraint stress on gastric emptying (GE) and the involvement of the hypothalamic paraventricular nucleus (PVN) were investigated in male Wistar rats (200-250 g body weight). Electrolytic lesions were produced stereotaxically in the nucleus by passing a 2.0-mA current for 10 s through stainless steel electrodes. GE was measured by means of a liquid test meal of 5% (w/v) glucose solution plus phenol red (6 mg/dl) dye as marker, given by orogastric infusion. Cold restraint stress induces a significant increase (43.7%, N = 11) in gastric retention of a 5% glucose solution in rats, i.e., a delay in GE of this solution. However, restraint stress alone does not produce any change. Both truncal vagotomy and electrolytic lesion of the PVN completely block the cold restraint-induced delay in GE. However, PVN lesion per se results in a decrease of GE (30.6%, N = 10) when compared to nonoperated controls. In addition, PVN-lesioned rats exposed to cold restraint present a slightly faster GE (14.7%, N = 11) than controls, demonstrating an opposite response to that initially observed without lesion. These data suggest an important role for PVN efferents, probably influencing medullary vagal preganglionic neurons, in the development of this gastric motor impairment under stress conditions.
在雄性Wistar大鼠（体重200 - 250克）中，研究了冷束缚应激对胃排空（GE）的影响以及下丘脑室旁核（PVN）的参与情况。通过不锈钢电极施加2.0毫安电流10秒，以立体定向方式在该核中产生电解损伤。通过经口胃灌注给予5%（w/v）葡萄糖溶液加酚红（6毫克/分升）染料作为标记物的液体试验餐来测量胃排空。冷束缚应激导致大鼠5%葡萄糖溶液的胃潴留显著增加（43.7%，N = 11），即该溶液的胃排空延迟。然而，单独的束缚应激不会产生任何变化。切断迷走神经干和PVN的电解损伤均完全阻断了冷束缚诱导的胃排空延迟。然而，与未手术的对照组相比，PVN损伤本身导致胃排空减少（30.6%，N = 10）。此外，暴露于冷束缚的PVN损伤大鼠的胃排空比对照组略快（14.7%，N = 11），表明与最初未损伤时观察到的反应相反。这些数据表明，在应激条件下这种胃运动障碍的发生过程中，PVN传出神经可能通过影响延髓迷走神经节前神经元发挥重要作用。
