5 Antifertility Agents

Progestin-Induced Pseudohermaphroditism in the Female Hamster

“…We cannot exclude the possibility that the behavioural masculinizing and defeminizing properties of norethynodrel could also be the result of its oestrogen¬ like structure. Although norethynodrel is a 19-nortestosterone derivative, it can be prepared as the reduction product of oestrone (Petrow, 1971) and its basic chemical structure is that of an 'oestren'. Recently, work in this laboratory (Paup, Coniglio & Clemens, 1972;Coniglio et al, 1973) has shown that behavioural masculinization and defeminization can be achieved by oestrogens as well as androgens which could be aromatized to oestrogens.…”

Progestin-Induced Pseudohermaphroditism in the Female Hamster

“…We cannot exclude the possibility that the behavioural masculinizing and defeminizing properties of norethynodrel could also be the result of its oestrogen¬ like structure. Although norethynodrel is a 19-nortestosterone derivative, it can be prepared as the reduction product of oestrone (Petrow, 1971) and its basic chemical structure is that of an 'oestren'. Recently, work in this laboratory (Paup, Coniglio & Clemens, 1972;Coniglio et al, 1973) has shown that behavioural masculinization and defeminization can be achieved by oestrogens as well as androgens which could be aromatized to oestrogens.…”

Oral Contraceptives: Therapeutics Versus Adverse Reactions, with an Outlook for the Future I*

“…A number of recent reviews (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) summarized the observations made in numerous studies since the late 1960's. Briefly, gonadotropin [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] secretion by the anterior pituitary is under the control of the hypothalamus which secretes small polypeptides into the portal system connecting the median eminence of the hypothalamus with the anterior pituitary.…”

“…During the preovulatory phase and especially just prior to ovulation, the cervical mucus becomes increasingly more favorable, in physicochemical char-acteristics, to the migration of sperm (15). It forms a thin, clear, watery liquid which can be stretched into threads (spjnnbarkeit).…”

“…One such mechanism involves the effect of the progestagen on the cervical mucus. In contrast to the watery mucus facilitatory to sperm penetration (15) present during the preovulatory phase of the untreated cycle and throughout the estrogenic phase of the sequential regimen, the mucus present during treatment with the combined preparations is similar to that found during the normal luteal phase; that is, the cervical mucus is thick, scanty, and cellular, providing a physical barrier to penetration by sperm (13). The physical barrier hypothesis, moreover, is supported by electron microscopic evidence (48) which indicates a close approximation of, and significant cross-linkages between, the main fibers comprising the cervical mucus obtained from women taking combined preparations.…”

“…In addition to their drawback of having a variable degree of effectiveness, progestagen-only preparations also produce a high incidence of menstrual irregularity manifested by breakthrough bleeding and prolonged cycles (15,26,50,59,62). Better cycle control can be obtained by administering estrogen in addition from Day 19 or 21 to Day 25 (68), the so-called reverse sequential regimen (26).…”

Progestin-Induced Pseudohermaphroditism in the Female Hamster

“…We cannot exclude the possibility that the behavioural masculinizing and defeminizing properties of norethynodrel could also be the result of its oestrogen¬ like structure. Although norethynodrel is a 19-nortestosterone derivative, it can be prepared as the reduction product of oestrone (Petrow, 1971) and its basic chemical structure is that of an 'oestren'. Recently, work in this laboratory (Paup, Coniglio & Clemens, 1972;Coniglio et al, 1973) has shown that behavioural masculinization and defeminization can be achieved by oestrogens as well as androgens which could be aromatized to oestrogens.…”

Oral Contraceptives: Therapeutics Versus Adverse Reactions, with an Outlook for the Future I*

“…A number of recent reviews (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) summarized the observations made in numerous studies since the late 1960's. Briefly, gonadotropin [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] secretion by the anterior pituitary is under the control of the hypothalamus which secretes small polypeptides into the portal system connecting the median eminence of the hypothalamus with the anterior pituitary.…”

“…During the preovulatory phase and especially just prior to ovulation, the cervical mucus becomes increasingly more favorable, in physicochemical char-acteristics, to the migration of sperm (15). It forms a thin, clear, watery liquid which can be stretched into threads (spjnnbarkeit).…”

“…One such mechanism involves the effect of the progestagen on the cervical mucus. In contrast to the watery mucus facilitatory to sperm penetration (15) present during the preovulatory phase of the untreated cycle and throughout the estrogenic phase of the sequential regimen, the mucus present during treatment with the combined preparations is similar to that found during the normal luteal phase; that is, the cervical mucus is thick, scanty, and cellular, providing a physical barrier to penetration by sperm (13). The physical barrier hypothesis, moreover, is supported by electron microscopic evidence (48) which indicates a close approximation of, and significant cross-linkages between, the main fibers comprising the cervical mucus obtained from women taking combined preparations.…”

“…In addition to their drawback of having a variable degree of effectiveness, progestagen-only preparations also produce a high incidence of menstrual irregularity manifested by breakthrough bleeding and prolonged cycles (15,26,50,59,62). Better cycle control can be obtained by administering estrogen in addition from Day 19 or 21 to Day 25 (68), the so-called reverse sequential regimen (26).…”

Progestin-Induced Pseudohermaphroditism in the Female Hamster

“…We cannot exclude the possibility that the behavioural masculinizing and defeminizing properties of norethynodrel could also be the result of its oestrogen¬ like structure. Although norethynodrel is a 19-nortestosterone derivative, it can be prepared as the reduction product of oestrone (Petrow, 1971) and its basic chemical structure is that of an 'oestren'. Recently, work in this laboratory (Paup, Coniglio & Clemens, 1972;Coniglio et al, 1973) has shown that behavioural masculinization and defeminization can be achieved by oestrogens as well as androgens which could be aromatized to oestrogens.…”

Oral Contraceptives: Therapeutics Versus Adverse Reactions, with an Outlook for the Future I*

“…A number of recent reviews (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15) summarized the observations made in numerous studies since the late 1960's. Briefly, gonadotropin [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] secretion by the anterior pituitary is under the control of the hypothalamus which secretes small polypeptides into the portal system connecting the median eminence of the hypothalamus with the anterior pituitary.…”

“…During the preovulatory phase and especially just prior to ovulation, the cervical mucus becomes increasingly more favorable, in physicochemical char-acteristics, to the migration of sperm (15). It forms a thin, clear, watery liquid which can be stretched into threads (spjnnbarkeit).…”

“…One such mechanism involves the effect of the progestagen on the cervical mucus. In contrast to the watery mucus facilitatory to sperm penetration (15) present during the preovulatory phase of the untreated cycle and throughout the estrogenic phase of the sequential regimen, the mucus present during treatment with the combined preparations is similar to that found during the normal luteal phase; that is, the cervical mucus is thick, scanty, and cellular, providing a physical barrier to penetration by sperm (13). The physical barrier hypothesis, moreover, is supported by electron microscopic evidence (48) which indicates a close approximation of, and significant cross-linkages between, the main fibers comprising the cervical mucus obtained from women taking combined preparations.…”

“…In addition to their drawback of having a variable degree of effectiveness, progestagen-only preparations also produce a high incidence of menstrual irregularity manifested by breakthrough bleeding and prolonged cycles (15,26,50,59,62). Better cycle control can be obtained by administering estrogen in addition from Day 19 or 21 to Day 25 (68), the so-called reverse sequential regimen (26).…”