therefore , a lipophobic quaternized derivative of naltrexone ( mrz 2663-naltrexone methobromide ) and dextro- ( + ) and levo- ( - ) stereoisomers of naloxone were used to study the site- and stereoselectivity of gonadotropin responses to opiate antagonists in vivo .
C0027360
naltrexone
C0027358
naloxone