[Antagonism of l-stepholidine against bromocriptine-inhibition on prolactin level in lactational rats].
OBJECTIVE
To study the antagonism of l-stepholidine (SPD) against bromocriptine (Bro)-inhibition on prolactin (PRL) level.


METHODS
Bro (0.5 mg.kg-1.d-1, s.c.) reduced the PRL and caused a dysplasia of mammary gland in lactational rats. The weight growing of newborn rats was retarded. The PRL of the lactational rats was assessed by immunoradiometric assay (IRMA); the weight of newborn rats and development of mammary glands in lactational rats were also examined. Antagonism of SPD was evaluated.


RESULTS
SPD (30 & 100 mg.kg-1.d-1, i.p.) obviously antagonized the Bro that induced lowering the PRL level in lactational rats, the PRL was 11 +/- 4 & 23 +/- 6 micrograms.L-1 (NS 7 +/- 2) respectively on d 15 of postpartum and the development of mammary gland in lactational rats was normal. The newborn rats grew rapidly in 11-15 d.


CONCLUSIONS
SPD possessed an antagonism with Bro inhibition on D2 receptors located in the pituitary gland, and was an antagonist of dopamine D2 receptors.
You
C L
CL
Department of Pharmacology, Liaoning Collge of Traditional Chinese Medicine, Shenyang, China.
Han
Z F
ZF
Qu
Y S
YS
Wang
Y M
YM
Chen
L J
LJ
Jin
G Z
GZ
D000818:Animals; D001599:Berberine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001971:Bromocriptine / Q000037:antagonists & inhibitors; D018491:Dopamine Agonists; D018492:Dopamine Antagonists / Q000494:pharmacology*; D005260:Female; D007774:Lactation; D011388:Prolactin / Q000097:blood*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D001599:Berberine; C010513:stepholidine; D001971:Bromocriptine; D011388:Prolactin