Downing S J, Hollingsworth M
Department of Physiological Sciences, University of Manchester, UK.
J Reprod Fertil. 1993 Sep;99(1):121-9. doi: 10.1530/jrf.0.0990121.
The influence of oestradiol benzoate and progesterone treatment and of tolerance to relaxin on the uptake of 125I-labelled porcine relaxin by reproductive tissues was investigated in anaesthetized female rats. In ovary-intact rats, 125I-labelled relaxin uptake increased with time in reproductive tissues and in tissues concerned with metabolism and excretion. Administration of 50 micrograms unlabelled porcine relaxin before injection of 125I-labelled relaxin significantly reduced uptake of 125I-labelled relaxin into the uterus and cervix, but had no effect on uptake of 125I-labelled relaxin into other tissues, indicating that specific uptake of relaxin was occurring in the uterus and cervix. In ovariectomized rats, treatment with oestradiol benzoate or oestradiol benzoate plus progesterone for 1 day did not significantly increase uterine or cervical 125I-labelled relaxin uptake compared with corn oil-treated rats, but induced a significant increase in uterine uptake of 125I-labelled relaxin after treatment for 2 days. Induction of tolerance to relaxin by i.v. infusion of a high dose of relaxin significantly reduced uterine and cervical uptake of 125I-labelled relaxin at 3 h after termination of infusion compared with saline-infused rats. By 12 h after termination of infusion, 125I-labelled relaxin uptake in the uterus and cervix was similar in saline-infused rats and in rats given an infusion of relaxin. Infusion of glibenclamide (20 mg kg-1) did not influence uterine or cervical uptake of 125I-labelled relaxin; however, treatment with phentolamine (10 mg kg-1) significantly reduced 125I-labelled relaxin uptake in uterus, bladder and jejunum. This study demonstrates that steroid hormone treatment and tolerance modulate relaxin uptake in reproductive tissues.
在麻醉的雌性大鼠中，研究了苯甲酸雌二醇和孕酮治疗以及对松弛素的耐受性对生殖组织摄取¹²⁵I标记的猪松弛素的影响。在卵巢完整的大鼠中，¹²⁵I标记的松弛素摄取量在生殖组织以及与代谢和排泄相关的组织中随时间增加。在注射¹²⁵I标记的松弛素之前给予50微克未标记的猪松弛素，可显著降低¹²⁵I标记的松弛素进入子宫和宫颈的摄取量，但对¹²⁵I标记的松弛素进入其他组织的摄取量没有影响，这表明子宫和宫颈中存在松弛素的特异性摄取。在去卵巢大鼠中，与玉米油处理的大鼠相比，用苯甲酸雌二醇或苯甲酸雌二醇加孕酮处理1天并未显著增加子宫或宫颈对¹²⁵I标记的松弛素的摄取，但在处理2天后可诱导子宫对¹²⁵I标记的松弛素的摄取显著增加。通过静脉输注高剂量的松弛素诱导对松弛素的耐受性，与输注生理盐水的大鼠相比，在输注终止后3小时，可显著降低子宫和宫颈对¹²⁵I标记的松弛素的摄取。在输注终止后12小时，输注生理盐水的大鼠和输注松弛素的大鼠子宫和宫颈中¹²⁵I标记的松弛素摄取量相似。输注格列本脲（20毫克/千克）不影响子宫或宫颈对¹²⁵I标记的松弛素的摄取；然而，用酚妥拉明（10毫克/千克）处理可显著降低子宫、膀胱和空肠中¹²⁵I标记的松弛素的摄取。这项研究表明，类固醇激素治疗和耐受性可调节生殖组织中松弛素的摄取。
