[Antifertility effect of the implant containing 16-methylene-17 alpha-acetoxy-19-norprogesterone (ST-1435)].
The silastic capsules containing ST-1435 (0.5, 1, 2, 4, 6 or 8 mg) showed "burst effect" with a peak value of 4-15 micrograms.h-1 after incubation in vitro. A constant release rate was gradually approached within 1-2 wk. After the capsules were subcutaneous implanted or vaginally administrated, the rats manifested diestrus within 24-48 h. The normal estrus cycles and fertility were restored as soon as the release rate of implants decreased to 10 micrograms.d-1 in vitro. ST-1435 did not inhibit the superovulation induced by PMSG and HCG in immature female rats, but blocked the ovulation induced by LHRH in mature rats.
Chu
Z W
ZW
Shanghai Institute of Materia Medica, Chinese Academy of Sciences.
Wang
W C
WC
Wang
Y E
YE
You
G D
GD
Gu
Z P
ZP
D000818:Animals; D003271:Contraceptive Agents, Female; D003692:Delayed-Action Preparations; D004031:Diestrus / Q000187:drug effects; D004343:Drug Implants; D005260:Female; D009653:Norprogesterones / Q000494:pharmacology*; D010060:Ovulation / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
D003271:Contraceptive Agents, Female; D003692:Delayed-Action Preparations; D004343:Drug Implants; D009653:Norprogesterones; C029167:ST 1435