Altuna María Eugenia, Lelli Sandra Marcela, San Martín de Viale Leonor C, Damasco María Cristina
Laboratorio de Esteroides, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Química Biológica Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
Can J Physiol Pharmacol. 2006 Oct;84(10):977-84. doi: 10.1139/y06-046.
Stress activates the synthesis and secretion of catecholamines and adrenal glucocorticoids, increasing their circulating levels. In vivo, hepatic 11beta-hydroxysteroid dehydrogenase 1 (HSD1) stimulates the shift of 11-dehydrocorticosterone to corticosterone, enhancing active glucocorticoids at tissue level. We studied the effect of 3 types of stress, 1 induced by bucogastric overload with 200 mmol/L HCl causing metabolic acidosis (HCl), the second induced by bucogastric overload with 0.45% NaCl (NaCl), and the third induced by simulated overload (cannula), on the kinetics of hepatic HSD1 of rats and their influence on the activity of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase, glycemia, and glycogen deposition. Compared with unstressed controls, all types of stress significantly increased HSD1 activity (146% cannula, 130% NaCl, and 253% HCl), phosphoenolpyruvate carboxykinase activity (51% cannula, 48% NaCl, and 86% HCl), and glycemia (29% cannula, 30% NaCl, and 41% HCl), but decreased hepatic glycogen (68% cannula, 68% NaCl, and 78% HCl). Owing to these results, we suggest the following events occur when stress is induced: an increase in hepatic HSD1 activity, augmented active glucocorticoid levels, increased gluconeogenesis, and glycemia. Also involved are the multiple events indirectly related to glucocorticoids, which lead to the depletion of hepatic glycogen deposits, thereby contributing to increased glycemia. This new approach shows that stress increments the activity of hepatic HSD1 and suggests that this enzyme could be involved in the development of the Metabolic Syndrome.
应激会激活儿茶酚胺和肾上腺糖皮质激素的合成与分泌,使其循环水平升高。在体内,肝脏11β-羟基类固醇脱氢酶1(HSD1)会刺激11-脱氢皮质酮向皮质酮的转化,从而在组织水平增强活性糖皮质激素。我们研究了三种应激类型的影响,第一种是用200 mmol/L盐酸进行胃内过载诱导代谢性酸中毒(HCl),第二种是用0.45%氯化钠进行胃内过载诱导(NaCl),第三种是模拟过载诱导(插管),观察其对大鼠肝脏HSD1动力学的影响以及对糖异生酶磷酸烯醇式丙酮酸羧激酶活性、血糖和糖原沉积的影响。与未应激的对照组相比,所有类型的应激均显著增加了HSD1活性(插管组增加146%,NaCl组增加130%,HCl组增加253%)、磷酸烯醇式丙酮酸羧激酶活性(插管组增加51%,NaCl组增加48%,HCl组增加86%)和血糖水平(插管组增加29%,NaCl组增加30%,HCl组增加41%),但降低了肝脏糖原含量(插管组降低68%,NaCl组降低68%,HCl组降低78%)。基于这些结果,我们认为在应激诱导时会发生以下事件:肝脏HSD1活性增加、活性糖皮质激素水平升高、糖异生增加以及血糖升高。还涉及与糖皮质激素间接相关的多个事件,这些事件导致肝脏糖原储备减少,从而导致血糖升高。这种新方法表明应激会增加肝脏HSD1的活性,并提示该酶可能参与代谢综合征的发生发展。