Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, Colima, Mexico.
Facultad de Medicina, Universidad de Colima, Colima, Mexico.
Adv Exp Med Biol. 2018;1071:143-149. doi: 10.1007/978-3-319-91137-3_18.
Leptin is a protein hormone that plays a key role in the regulation of energy balance and glucose homeostasis. Leptin and all leptin receptor isoforms are present in the carotid bodies, but its precise function in glucose regulation and metabolism is not yet known. The aim of this study was to determine whether exogenous leptin, microinjected into the commissural nucleus tractus solitarii (cNTS), preceding sodium cyanide (NaCN) injection into the circulatory isolated carotid sinus (ICS), in vivo, modifies hyperglycemic reflex (HR) and brain glucose retention (BGR). In anesthetized Wistar rats (sodium pentobarbital, i.p. 3.3 mg/100 g/saline, Pfizer, Mex), arterial and venous blood samples were collected from silastic catheters implanted in the abdominal aorta and jugular sinus. Exogenous leptin (50 ng/20 nL of aCSF) or leptin vehicle (20 nL of aCSF) microinjected (stereotaxically) into the cNTS 4 min before NaCN (5 μg/100 g/50 μL saline into ICS) (experimental 1 [E1] and control 1[C1] groups, respectively) significantly increased HR and BGR compared with their basal values, but the increase was bigger in the E1 group. When leptin or aCSF were injected into the cNTS before saline (E2 and C2 groups, respectively) glucose responses did not vary when compared with their basal levels. Leptin and its receptors in the cNTS cells probably contribute to their sensitization during hypoxia.
瘦素是一种蛋白质激素，在调节能量平衡和葡萄糖稳态方面发挥着关键作用。瘦素和所有瘦素受体同工型都存在于颈动脉体中，但它在葡萄糖调节和代谢中的精确功能尚不清楚。本研究旨在确定外源性瘦素在体内是否会改变高血糖反射（HR）和脑葡萄糖保留（BGR），方法是在循环隔离颈动脉窦（ICS）中注射氰化钠（NaCN）之前，将其微注射到连合核束状核（cNTS）中。在麻醉的 Wistar 大鼠（戊巴比妥钠，腹腔内 3.3 mg/100 g/盐水，辉瑞，墨西哥）中，从植入腹主动脉和颈静脉窦的硅橡胶导管中采集动脉和静脉血样。外源性瘦素（50ng/20nL 的 aCSF）或瘦素载体（20nL 的 aCSF）在 NaCN（5μg/100g/50μL 盐水注入 ICS）前 4 分钟（实验 1 [E1]和对照 1 [C1]组，分别）微注射（立体定向）到 cNTS 中，与基础值相比，HR 和 BGR 显著增加，但 E1 组的增加更大。当瘦素或 aCSF 在盐水之前注入 cNTS 时（E2 和 C2 组，分别），与基础水平相比，葡萄糖反应没有变化。cNTS 细胞中的瘦素及其受体可能有助于它们在缺氧期间的敏化。
