左旋四氢巴马汀对哺乳期大鼠催乳素水平低下的拮抗作用

目的研究左旋四氢巴马汀(l-tetrahydropalmatine,l-THP)对溴隐亭(Bromocriptine,Bro)诱导的哺乳期大鼠催乳素(Prolactin,PRL)水平低下的拮抗作用,以证实其为中枢多巴胺能D2受体拮抗剂.方法通过对哺乳期大鼠皮下注射(sc)Bro 0.5 mg/kg,建立哺乳期大鼠PRL水平低下模型.在此模型基础上,腹腔注射(ip)l-THP 6 mg/kg及18 mg/kg,研究l-THP对Bro诱导的哺乳期大鼠PRL水平低下的拮抗作用.结果sc Bro 0.5 mg/kg可显著降低哺乳期大鼠血清PRL水平,其仔鼠体重增长缓慢,并且母鼠乳腺组织发育不良.ip l-THP 6 mg/kg及18 mg/kg可显著提高用Bro造模的哺乳期大鼠血清PRL水平,促进其仔鼠体重增长,并且母鼠乳腺组织发育良好.结论l-THP能阻断大鼠脑垂体前叶D2受体,是中枢D2受体拮抗剂.

Counteraction of L - tetrahydropalmatine Against Bromocriptine - induced Hypoprolactin in Lactational Rats

Objective To study the counteraction of l- tetrahydropalmatine (l- THP) against bromocriptine (Bro)- induced hypoprolactin in lactational rats and to prove that l- THP is an antagonist of dopamine D2 receptors. Methods The lactational rat model with hypoprolactin was established by subcutaneous injection of Bro (0.5 mg/kg).The counteraction of l- THP (6 and 18 mg/kg, ip)was evaluated by observing serum prolactin (PRL) level, weight growing in newly born rats, and histology changes of mammary gland. Results Bro (0.5 mg/kg, sc) reduced the PRL level and induced the dysplasia of mammary gland in lactational rats. Bro also caused the retardation of the weight growing in newly- born rats. l- tetrahydropalmatine 6 and 18 mg/kg ip remarkably increased the prolactin level and promoted the development of mammary gland in lactational rats models and promoted the weight growing in newly- born rats. Conclusion l- tetrahydropalmatine(l- THP) has an antagonism against dopamine D2 receptors.