Role of the pituitary in reflex natriuresis following acute unilateral nephrectomy.
Role of the pituitary in reflex natriuresis following acute unilateral nephrectomy.
复制标题
垂体在急性单侧肾切除术后反射性尿钠中的作用。
DOI：
10.1152/ajprenal.1985.249.2.f282
复制
发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Humphreys,MH
中科院分区：
文献类型：
--
作者：
Lin,SY;Wiedemann,E;Humphreys,MH
我们研究了急性单侧肾切除术（AUN）后垂体功能改变在反射性尿钠排泄中的作用。在正常大鼠中，AUN增加钠（UNAV）和钾的排泄在90分钟内。在垂体切除大鼠中，没有增加阳离子排泄后，AUN发生，这是重复的结果，在大鼠垂体功能的改变与地塞米松（2毫克/公斤ip 3天）的预先治疗。在肾上腺切除大鼠中，AUN导致阳离子排泄增加，与正常大鼠相似，表明AUN后的排泄反应不需要完整的肾上腺功能。阳离子排泄的这些变化与来自垂体前体分子阿黑皮素原（POMC）的两种肽在外周血浆中的测量值相关。放射免疫分析血浆β-内啡肽未能改变后，AUN在任何条件下的研究。然而，POMC的N-末端片段（NTF）的灵敏的放射免疫分析表明，血浆NTF上升后AUN在正常和肾上腺切除大鼠显着，但没有改变垂体切除，类固醇预处理，或假手术大鼠。NTF浓度的增加与AUN后UNaV的增加相关。这些结果表明，反射性增加阳离子排泄后AUN是依赖于一个完整的垂体，并与外周血浆浓度的NTF的增加。NTF或POMC N-末端的其他肽可促进AUN后的尿钠排泄;垂体在这种反应中的重要性可能是这种肽的分泌。
We studied the role of altered pituitary function in the reflex natriuresis that occurs after acute unilateral nephrectomy (AUN). In normal rats, AUN increased both sodium (UNaV) and potassium excretion within 90 min. In hypophysectomized rats, no increase in cation excretion after AUN occurred, results which were duplicated in rats in which pituitary function was altered by prior treatment with dexamethasone (2 mg/kg ip for 3 days). In adrenalectomized rats, AUN led to increases in cation excretion similar to those seen in normal rats, indicating that intact adrenal function was not necessary for this excretory response following AUN. These changes in cation excretion were correlated with measurements in peripheral plasma of two peptides derived from the pituitary precursor molecule pro-opiomelanocortin (POMC). Radioimmunoassayable plasma beta-endorphin failed to change after AUN in any of the conditions studied. However, a sensitive radioimmunoassay for the N-terminal fragment (NTF) of POMC indicated that plasma NTF rose significantly after AUN in normal and adrenalectomized rats but did not change in hypophysectomized, steroid-pretreated, or shamoperated rats. The increase in NTF concentration correlated with the increase in UNaV after AUN. These results demonstrate that the reflex increase in cation excretion after AUN is dependent on an intact pituitary gland and is associated with an increase in peripheral plasma concentration of NTF. NTF, or some other peptide residing in the N-terminal portion of POMC, could promote the natriuresis after AUN; the importance of the pituitary gland in this response could be the secretion of this peptide.