Servomechanism of prolactin and XXXX in regulating uterine gene expression.

@entity8723 @entity95 @entity1420 @entity53
To investigate the interaction of PRL and @entity1420 in regulating uterine gene expression, we have quantitated the concentration of PRL receptor and of uteroglobin (UG) mRNA in the endometrium of @entity95 of different ages and after treatment with different hormones. During uterine differentiation in 2- to 4-week old @entity95 , a marked increase in unoccupied uterine PRL receptor number was observed, presumably increasing uterine sensitivity to PRL. Receptor values for 4-week old @entity95 were comparable to values for sexually mature, estrous females, but were lower than in 5-day pseudopregnant (PSP) animals. When total PRL receptor was determined by Scatchard analysis after in vitro desaturation with @entity8723 , PSP animals again expressed the highest receptor concentration with no changes in the dissociation constant (Kd) values. To determine whether @entity1420 regulates uterine PRL receptor, long term ovariectomized @entity95 (greater than 12 weeks) were treated with various combinations of hormones, and unoccupied and total uterine PRL receptors were determined. @entity1420 treatment resulted in the highest concentration of both unoccupied and total PRL receptor after desaturation and removal of anti-ovine PRL antibodies with @entity8723 . The value for total uterine PRL receptor was equivalent to the value for mammary gland, and the Kd values (2-4 x 10(-10) M) were similar. Treatment of long term ovariectomized @entity95 with @entity1420 , with or without @entity53 , produced an increase (P less than 0.05) in the UG mRNA content, which also occurred in PSP animals. PRL alone had no effect on UG mRNA but PRL plus @entity1420 increased (P less than 0.05) UG mRNA in a dose-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)
