Dose and time relationships of intravenously injected rat recombinant luteinizing hormone and testicular testosterone secretion in the male rat
Dose and time relationships of intravenously injected rat recombinant luteinizing hormone and testicular testosterone secretion in the male rat
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DOI：
10.1095/biolreprod59.2.338
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发表时间：
1998-08-01
影响因子：
3.6
通讯作者：
Huhtaniemi, I
中科院分区：
文献类型：
--
作者：
Hakola, K;Pierroz, DD;Huhtaniemi, I
hCG和LH诱导Leydig细胞分泌睾酮（T）的能力已得到充分证实。然而，LH分泌的脉动性质（具有不同的频率和幅度）对体内T产生的影响尚不清楚。在我们早期对成年雄性大鼠脉冲式LH释放和T分泌之间关系的研究中，没有观察到简单的因果关系。最近大鼠重组（rec）LH的可用性促使我们研究了一个和三个静脉注射不同剂量的大鼠rec LH脉冲对成年雄性大鼠T分泌的影响，这些大鼠通过GnRH拮抗剂西曲瑞克治疗而致促性腺激素低下。一个或三个超生理脉冲的1.0微克大鼠recLH产生类似的最大T反应。与此相反，高生理LH脉冲（0.1 μ g）产生离散的T-反应峰，而多个低脉冲的LH（0.03 μ g）之前，需要实现T反应。如果在前一天用0.03 μ g与0.1 μ g大鼠recLH脉冲处理大鼠，则在0.1 μ g LH脉冲后T刺激大大减弱，这显然是因为GnRH拮抗剂处理导致LH剥夺延长和间质细胞引发缺乏。大鼠recLH的新制剂为研究雄性大鼠中脉冲式LH释放和T分泌之间的复杂关系提供了生理相关的工具。
The ability of hCG and LH to induce testosterone (T) secretion by Leydig cells is well documented. However, the influence of the pulsatile nature of LH secretion, with varying frequency and amplitude, on T production in vivo is less clear. In our earlier studies on the relationship between pulsatile LH release and T secretion in adult male rats, no simple causality was observed. The recent availability of rat recombinant (rec) LH prompted us to study the effects of one and of three i.v. pulses of different doses of rat recLH on T secretion in adult male rats rendered hypogonadotropic by treatment with the GnRH antagonist cetrorelix. One or three supraphysiological pulses of 1.0 mu g of rat recLH produced similar maximal T responses. In contrast, high physiological LH pulses (0.1 mu g) produced discrete T-response peaks, whereas multiple low pulses of LH (0.03 mu g) were needed before a T response was achieved. The T stimulation was greatly diminished after an LH pulse of 0.1 mu g if rats had been treated on the previous day with pulses of 0.03 vs. 0.1 mu g rat recLH, apparently because of prolonged LH deprivation and lack of Leydig cell priming due to the GnRH antagonist treatment. The novel preparation of rat recLH provides a physiologically relevant tool for studying the complex relationship between pulsatile LH release and T secretion in male rats.