Paradoxical growth-promoting effects induced by patterned infusions of somatostatin in female rats.
Paradoxical growth-promoting effects induced by patterned infusions of somatostatin in female rats.
复制标题
雌性大鼠中生长抑素模式输注诱导的反常生长促进作用。
作者：
R. Clark;I. Robinson
在以前的研究中，静脉输注生长激素或其释放因子（GRF），我们表明，脉冲式的生长激素比连续生长激素暴露在刺激生长的大鼠更有效。由于GH的释放是深刻的影响，其抑制因子，生长抑素（SS），我们有兴趣知道是否SS对GH的分泌和生长的影响也依赖于它的管理模式。通过可编程多通道输注泵向清醒的慢性插管雌性大鼠静脉输注SS。多个血液样品获得与使用的泵，电磁流体阀，和一个馏分收集器，所有由微机控制的自动化系统。SS输注（5、25或50微克/小时）抑制GH分泌，并在停止输注后引起GH快速、短暂的反弹释放。雌性大鼠正弦SS输注产生周期性GH分泌事件，但最好通过延长输注时间（每3小时中断一次SS输注）实现定期3小时GH分泌脉冲的雄性类型。这种间歇性SS输注模式引起了一系列重复的GH分泌反弹爆发，增加了体重增加和垂体GH含量。相比之下，连续输注等量的SS对体重增加没有影响，并显着降低骨生长。因此，SS对生长的影响确实取决于其施用的模式，并且这种本身强烈抑制GH分泌的肽在以促进更脉动的GH分泌模式的方式给予时矛盾地刺激正常动物的体重增加。
In previous studies with iv infusions of GH or its releasing factor (GRF), we showed that a pulsatile pattern of GH was more effective than continuous GH exposure in stimulating growth in the rat. Since GH release is profoundly affected by its inhibitory factor, somatostatin (SS), we were interested to know whether the effects of SS on GH secretion and growth were also dependent on its pattern of administration. SS infusions were given iv to conscious chronically cannulated female rats through programmable multichannel infusion pumps. Multiple blood samples were obtained with the use of an automated system of pumps, solenoid fluid valves, and a fraction collector, all controlled by a microcomputer. SS infusions (5, 25, or 50 micrograms/h) suppressed GH secretion and elicited a rapid, short-lived rebound release of GH after stopping the infusion. Sinusoidal SS infusions in female rats produced cyclic episodes of GH secretion, but a male type of regular 3-hourly secretory pulses of GH was best achieved by prolonged infusions in which the delivery of SS was interrupted for a short period every 3 h. This intermittent SS infusion pattern elicited a repetitive series of rebound bursts of GH secretion, which increased body weight gain and pituitary GH content. In contrast, continuous infusions of equivalent amounts of SS had no effect on body weight gain and reduced bone growth significantly. Thus the effects of SS on growth do depend on the pattern in which it is administered, and this peptide, which itself powerfully inhibits GH secretion, paradoxically stimulates weight gain in a normal animal when given in a manner that promotes a more pulsatile GH secretory pattern.
登录
查看更多内容
生长抑素 28 比生长抑素 14 对垂体和胰腺激素的释放作用更长、选择性更强。
影响因子：
4.8
作者：
Tannenbaum,GS;Ling,N;Brazeau,P
通讯作者：
Brazeau,P
影响因子：
56.9
作者：
GUILLEMIN, R;BRAZEAU, P;WEHRENBERG, WB
通讯作者：
WEHRENBERG, WB
生长激素自动反馈调节机制：生长抑素和生长激素释放因子的可能作用。
影响因子：
4.8
作者：
Conway,S;McCann,SM;Krulich,L
通讯作者：
Krulich,L
DOI：
10.1073/pnas.79.24.7659
发表时间：
1982-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
EVANS, RM;BIRNBERG, NC;ROSENFELD, MG
通讯作者：
ROSENFELD, MG
生长抑素类似物抑制培养的下丘脑细胞分泌生长抑素。
影响因子：
4.1
作者：
Peterfreund,RA;Vale,WW
通讯作者：
Vale,WW