Caldwell F T, Graves D B, Wallace B H
University of Arkansas for Medical Sciences, Department of Surgery, Little Rock 72205-7199.
J Burn Care Rehabil. 1994 Jul-Aug;15(4):315-22. doi: 10.1097/00004630-199407000-00005.
Rats, with the preoptic anterior hypothalamus implanted with two thermodes and a thermocouple reentry tube, had simultaneous direct and indirect calorimetry performed [during the ninth to eleventh postburn day interval] at ambient temperatures of 22 degrees and 28 degrees C. During calorimetry, blood was drawn at baseline and near the end of each period of displacement of the preoptic anterior hypothalamus temperature for catecholamine assay. Cooling the preoptic anterior hypothalamus resulted in a significant increase in heat production and plasma epinephrine and norepinephrine concentrations for both burn and control groups at 22 degrees C and 28 degrees C (p < 0.05 for all comparisons). Heat production demonstrated consistent negative linear correlation with preoptic anterior hypothalamic temperature. Plasma epinephrine values correlated with preoptic anterior hypothalamic temperature for only the controls at 28 degrees C ambient, whereas norepinephrine had significant linear correlation with heat production for all groups and significant negative linear correlation with preoptic anterior hypothalamic temperature. These data indicate norepinephrine may be more important than epinephrine in the maintenance of postburn hypermetabolism in this rat burn model while demonstrating that the hypermetabolism is appropriately responsive to perturbation of preoptic anterior hypothalamic temperature.
在大鼠的视前区下丘脑前部植入两个温度调节装置和一个热电偶再入管，于环境温度22℃和28℃时，在烧伤后第9至11天期间，对大鼠同时进行直接和间接热量测定。在热量测定期间，在视前区下丘脑前部温度每次移位的基线期和接近末期采集血液，用于儿茶酚胺测定。对视前区下丘脑前部进行冷却，结果显示，在22℃和28℃时，烧伤组和对照组的产热以及血浆肾上腺素和去甲肾上腺素浓度均显著增加（所有比较的p<0.05）。产热与视前区下丘脑前部温度呈一致的负线性相关。仅在环境温度28℃时，对照组的血浆肾上腺素值与视前区下丘脑前部温度相关，而去甲肾上腺素与所有组的产热呈显著线性相关，与视前区下丘脑前部温度呈显著负线性相关。这些数据表明，在该大鼠烧伤模型中，去甲肾上腺素在维持烧伤后高代谢方面可能比肾上腺素更重要，同时表明高代谢对视前区下丘脑前部温度的扰动有适当反应。
