Plasma leptin and ghrelin in the neonatal rat: interaction of dexamethasone and hypoxia
Plasma leptin and ghrelin in the neonatal rat: interaction of dexamethasone and hypoxia
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DOI：
10.1677/joe.1.06159
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发表时间：
2005-06-01
影响因子：
4
通讯作者：
Raff, H
中科院分区：
文献类型：
--
作者：
Bruder, ED;Jacobson, L;Raff, H
胃饥饿素、瘦素和内源性糖皮质激素在食欲调节、能量平衡和生长中发挥作用。本研究评估地塞米松（DEX）对这些激素的影响。在一种常见的代谢应激-新生儿缺氧期间，影响ACTH和垂体促肾上腺皮质激素释放激素受体-1 (CRHR1) mRNA的表达。新生大鼠在室内空气（21% O-2）或常压低氧（12% O-2）下从出生到出生后（PD） 7。给药于PD3(0)。5 mg/kg), PD4 （0 mg/kg）25 mg/kg), PD5 （0 mg/kg）125 mg/kg), PD6 （0 mg/kg）05 mg/ kg)。用PD7（末次给药后24 h）对幼犬进行研究。DEX显著提高了常氧幼崽的血浆瘦素和胃饥饿素，但只增加了缺氧幼崽的血浆胃饥饿素。仅缺氧就会导致血浆瘦素的少量增加。末次给药后24 h血浆皮质酮和垂体POMC mRNA表达降低，而血浆ACTH和垂体CRHR1 mRNA表达已升高（常氧和缺氧）。单独缺氧使皮质酮升高，但对ACTH、垂体POMC和CRHR1 mRNA表达无影响。新生儿DEX治疗、缺氧以及两者联合影响参与能量稳态的激素。新生儿垂体功能在dex诱导的下丘脑-垂体-肾上腺轴抑制后迅速恢复。胃促生长素、瘦素和皮质酮的变化可能通过维持食欲和改变中间代谢而有利于缺氧新生儿。
Ghrelin, leptin, and endogenous glucocorticoids play a role in appetite regulation, energy balance, and growth. The present study assessed the effects of dexamethasone (DEX) on these hormones. and on ACTH and pituitary proopiomelanocortin (POMC) and corticotropin-releasing hormone receptor-1 (CRHR1) mRNA expression, during a common metabolic stress - neonatal hypoxia. Newborn rats -,were raised in room air (21% O-2) or under normobaric hypoxia (12% O-2) from birth to postnatal day (PD) 7. DEX was administered on PD3 (0(.)5 mg/kg), PD4 (0(.)25 mg/kg), PD5 (0(.)125 mg/kg), and PD6 (0(.)05 mg/ kg). Pups were studied on PD7 (24 h after the last dose of DEX). DEX significantly increased plasma leptin and ghrelin in normoxic pups, but only increased ghrelin in hypoxic pups. Hypoxia alone resulted in a small increase in plasma leptin. Plasma corticosterone and pituitary POMC mRNA expression were decreased 24 h following the last dose of DEX, whereas plasma ACTH and pituitary CRHR1 mRNA expression had already increased (normoxia and hypoxia). Hypoxia alone increased corticosterone, but had no effect on ACTH or pituitary POMC and CRHR1 mRNA expression. Neonatal DEX treatment, hypoxia, and the combination of both affect hormones involved in energy homeostasis. Pituitary function in the neonate was quickly restored following DEX-induced suppression of the hypothalamic-pituitary-adrenal axis. The changes in ghrelin, leptin, and corticosterone may be beneficial to the hypoxic neonate through the maintenance of appetite and shifts in intermediary metabolism.