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.

Objective: To study the Antitussive, expectorant and antiasthmatic actions of Zhisou Lixiao capsule(ZLC). Methods: The incubation period and the frequency of cough in mice induced by ammonia water, the secretion of PSP from mouse bronchus and the incubation period of asthma in guinea-pigs induced by histamine were observed. Results: ZLC 0.8～3.2g?kg-1?d-1 ig could obviously prolong the incubative period of cough and decrease the frequency, ZLC 0.8～3.2g?kg-1?d-1 ig could increase the secretion of PSP in mice, 0.5～2.0 g?kg-1?d-1 increase the bronchial secretion in rats, and 1.0～2.0 g?kg-1?d-1 could prolong the incubation period of asthma in guinea-pigs. Conclusion: ZLC exerts a good Antitussive, expectorant and antiasthmatic effect.