Anastrozole is a potent, highly selective aromatase inhibitor, which inhibits human placental aromatase with an IC50 of 15 nM.
Description :
Anastrozole has high intrinsic potency in vitro and inhibits human placental aromatase with an IC50 of 15 nM. Anastrozole it is 200 times as potent as AG, twice as potent as 4-OHA and one third as potent as fadrozole. [1]. Anastrozole inhibits aromatase by binding competitively to the hem group of the CYP unit of the enzyme thereby reducing estrogen biosynthesis in the periphery and the breast. Anastrozole has little or no effect on other steroid hormones. [2]
Groups of eight immature (22-day-old) female rats are given androstenedione (AD) (30 mg/kg) in arachis oil s.c. daily for 3 days with or without various doses of Anastrozole p.o. on day 4 the uteri are dissected, blotted and weighed. An oral dose of 0.1 mg/kg of Anastrozole given on day 2 or day 3 of the cycle completely blocked ovulation. At the same daily dosage (0.1 mg/kg), Anastrozole completely extinguished the uterotrophic activity of exogenous AD in immature rats. In male pigtailed monkeys, twice-daily oral treatment with 0.1 mg/kg and above of Anastrozole reduced circulating oestradiol concentrations by 50-60%[1].