Broman M, Källskog O, Kopp U C, Wolgast M
Department of Physiology and Medical Biophysics, University of Uppsala, Sweden.
Acta Physiol Scand. 1998 Jul;163(3):241-9. doi: 10.1046/j.1365-201x.1998.00356.x.
Hypothermia increases preglomerular vasoconstriction leading to decreases in renal blood flow (RBF) and glomerular filtration rate (GFR). Since plasma catecholamine concentrations are increased during hypothermia, the present study was performed to determine the role of the renal sympathetic nervous system in the cold-induced renal vasoconstriction. In Inactin anaesthetized rats, hypothermia at 28 degrees C decreased GFR by 50% but failed to alter efferent renal sympathetic nerve activity (ERSNA). Since hypothermia causes shivering which could have influenced the ERSNA recording, Inactin anaesthetized rats were treated with pethidine or rats were anaesthetized with pentobarbital sodium or Saffan to eliminate cold-induced shivering. In these non-shivering rats, hypothermia produced a reversible decrease in ERSNA in association with a fall in GFR that was of a similar magnitude as in shivering rats. Further studies in Inactin anaesthetized rats showed that the fall in GFR was unaltered by renal denervation, bilateral adrenalectomy or intrarenal administration of the alpha 1-adrenoceptor antagonist prazosin. We conclude that cold-induced renal vasoconstriction is not due to an increase in ERSNA or adrenaline/noradrenaline-mediated activation of renal alpha 1-adrenoceptors.
体温过低会增加肾前血管收缩，导致肾血流量（RBF）和肾小球滤过率（GFR）降低。由于体温过低时血浆儿茶酚胺浓度会升高，因此进行了本研究以确定肾交感神经系统在寒冷诱导的肾血管收缩中的作用。在使用安泰酮麻醉的大鼠中，28摄氏度的低温使GFR降低了50%，但未能改变肾传出交感神经活动（ERSNA）。由于体温过低会导致颤抖，这可能会影响ERSNA记录，因此对使用安泰酮麻醉的大鼠用哌替啶治疗，或者用戊巴比妥钠或三碘季铵酚麻醉大鼠以消除寒冷诱导的颤抖。在这些不颤抖的大鼠中，低温导致ERSNA可逆性降低，同时GFR下降，其幅度与颤抖大鼠相似。对使用安泰酮麻醉的大鼠进行的进一步研究表明，肾去神经支配、双侧肾上腺切除术或肾内给予α1肾上腺素能受体拮抗剂哌唑嗪均未改变GFR的下降。我们得出结论，寒冷诱导的肾血管收缩并非由于ERSNA增加或肾上腺素/去甲肾上腺素介导的肾α1肾上腺素能受体激活所致。
