Kuroshima A, Yahata T, Ohno T
Department of Physiology, Asahikawa Medical College, Japan.
Jpn J Physiol. 1988;38(2):199-207. doi: 10.2170/jjphysiol.38.199.
The effects of noradrenaline (NA) injection (40 micrograms/100 g, i.p.) on plasma glucagon, corticosterone (CS), deoxycorticosterone (DOCS), glucose, and free fatty acids (FFA) were investigated in cold-acclimated rats (CA) and warm controls (WC). The CA were transferred to warm control temperature ca. 18 h prior to NA or saline injection. The animals were decapitated and the trunk blood was collected 0, 10, 20, and 40 min after the injection. Plasma glucagon level increased significantly during the experimental period after NA, while saline did not influence its level. The magnitude of increase as assessed by 95% confidence interval was significantly greater in CA than in WC. Plasma CS and DOCS were significantly increased by saline injection, but NA caused greater elevations of these steroid-hormones. The magnitudes of increases were also greater in CA. In contrast to the hormonal responses, NA-induced increases of plasma glucose and FFA levels were smaller in CA than in WC. These results suggest that glucagon and glucocorticoids are released, at least partly, by NA, and these thermogenic factors act in synergism, enhancing nonshivering thermogenesis through an accelerated utilization of energy substrates such as glucose and FFA.
研究了去甲肾上腺素（NA）注射（40微克/100克，腹腔注射）对冷适应大鼠（CA）和温暖对照组（WC）血浆胰高血糖素、皮质酮（CS）、脱氧皮质酮（DOCS）、葡萄糖和游离脂肪酸（FFA）的影响。在注射NA或生理盐水前约18小时，将冷适应大鼠转移至温暖的对照温度环境。注射后0、10、20和40分钟时，将动物断头并采集躯干血。NA注射后的实验期间，血浆胰高血糖素水平显著升高，而生理盐水对其水平无影响。通过95%置信区间评估，冷适应大鼠胰高血糖素水平升高幅度显著大于温暖对照组。注射生理盐水可显著提高血浆CS和DOCS水平，但NA使这些类固醇激素升高幅度更大。冷适应大鼠中这些激素升高的幅度也更大。与激素反应相反，NA诱导的血浆葡萄糖和FFA水平升高在冷适应大鼠中比温暖对照组小。这些结果表明，胰高血糖素和糖皮质激素至少部分由NA释放，并且这些产热因子协同作用，通过加速利用葡萄糖和FFA等能量底物来增强非寒战产热。
