A QUANTITATIVE-ANALYSIS OF THE ROLES OF DOSAGE, SEQUENCE, AND DURATION OF ESTRADIOL AND PROGESTERONE EXPOSURE IN THE REGULATION OF MATERNAL-BEHAVIOR IN THE RAT
A QUANTITATIVE-ANALYSIS OF THE ROLES OF DOSAGE, SEQUENCE, AND DURATION OF ESTRADIOL AND PROGESTERONE EXPOSURE IN THE REGULATION OF MATERNAL-BEHAVIOR IN THE RAT
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DOI：
10.1210/endo-114-3-930
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发表时间：
1984-01-01
期刊：
影响因子：
4.8
通讯作者：
BRIDGES, RS
中科院分区：
文献类型：
--
作者：
BRIDGES, RS
大鼠母性行为的发生受到荷尔蒙的控制。报道了一种新的内分泌模型，用于研究激素对母体反应的调节。该模型通过硅胶植入物向未经产妇的大鼠注入生理剂量的类固醇雌二醇(E2)和孕酮(P)，并测量这些植入物对母体行为的影响。在前两个实验中，用放射免疫法测定了妊娠大鼠和激素处理大鼠血清中雌二醇和孕酮的水平。利用已知的E_2与P联合给予的生理处理，测量了E_2和P对母体行为的影响。在去除P和行为学测试之前，用所有剂量的E2和P联合治疗2wk，可刺激去卵巢未分娩大鼠的母性行为快速发生。暴露在小型E2植入物(1或2 mm；.apprx.20-30pg/ml血清)不影响母体反应性，而大剂量E2植入(10 mM；.apprx)。110 pg/ml血清)刺激母体行为。P单独处理对小鼠的行为没有影响。在接触FoodYoung之前同时去除E2和P也会导致行为反应的刺激，这表明循环中E2效价的升高并不是刺激发生的必要条件。除了促进行为的快速开始，激素刺激的大鼠的反应质量与在T迷宫测试中测得的哺乳期大鼠的反应质量相似。在另一项实验中，当雌性大鼠在服用E2之前服用P时，母性行为被迅速诱导。因此，P本身可以使雌性对E2的行为影响敏感。检测前接触类固醇的时间长短会影响母亲的行为。在测试前增加E2加P暴露的持续时间伴随着母性反应的潜伏期的减少。在怀孕期间，雌激素E_2和孕酮使雌性在出生时对幼崽做出反应。随着妊娠的进展，类固醇启动的强度增加，这种启动的潜力随后被P的下降和分娩前后E2分泌的维持所掩盖。由于内分泌状态的长期变化，即怀孕，成年动物的行为过程显然可以改变。
The regulation of the onset of maternal behavior in the rat is under hormonal control. A new endocrine model for the study of the hormonal regulation of maternal responsiveness is reported. The model employs the administration of physiological amounts of the steroids estradiol (E2) and progesterone (P) via Silastic implants to inexperienced nulliparous rats and measurement of the effects of these implants on maternal behavior. In the first 2 experiments, the levels of E2 and P in the sera of pregnant and hormone-treated rats were measured by RIA [radioimmunoassay]. Using known physiological treatments of E2 given in combination with P, the effects of E2 and P on maternal behavior were measured. Treatment with a combination of E2 at all dosages plus P for 2 wk before P removal and behavioral testing stimulated a fast onset of maternal behavior in ovariectomized nulliparous rats. Exposure for 2 wk to small E2 implants (1 or 2 mm; .apprx. 20-30 pg/ml serum) did not affect maternal responsiveness, whereas large E2 implants (10 mm; .apprx. 110 pg/ml serum) stimulated maternal behavior. P treatment alone had no behavioral effect. Simultaneous removal of E2 plus P before exposure to foster young also resulted in a stimulation of behavioral responsiveness, indicating that the presence of elevated titers of circulating E2 is not a requirement for stimulation to occur. In addition to facilitating a rapid onset of behavior, the quality of the response in steroid-primed rats was similar to that measured in lactating rats in a T-maze test. In another experiment, when female rats were treated with P before E2 administration, maternal behavior was rapidly induced. Thus, P itself can sensitize the female to the behavioral effects of E2. The duration of steroid-exposure before testing influenced maternal behavior. Increased durations of E2 plus P exposure before testing were accompanied by decreased latencies to respond maternally to foster young. During pregnancy, E2 and P prime the female to respond to her young at birth. The intensity of the steroidal priming increases as pregnancy progresses, and this primed potential is subsequently unmasked by the decline in P and the maintenance of E2 secretion around parturition. Behavioral processes apparently can be modified in the adult animal as a result of long-term changes in endocrine state, i.e., pregnancy.