The Effect of Lynestrenol) on Animal Reproduction

Overbeek, G. A.; Madjerek, Z.; Visser, J. de

doi:10.1530/acta.0.0410351

Cited by 28 publications

(8 citation statements)

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“…It was not expected, however, that treatment with lynoestrenol, a dominant progestational steroid, would also result in reduction of uterine histamine. The weak oestrogenic activity reported for lynoestrenol (Overbeek, Madjerek & Divisser, 1962;Okada, Amatsu, Ishihara & Tokuda, 1964;Paulsen, 1965) has also been shown by the effect of this steroid on the vaginal smear (Abdel-Aziz et al, 1974) and the histological changes in the uterus observed in the present work. The reduction in uterine histamine observed after treatment with lynoestrenol might thus be mediated through its oestrogenic action or through its progesta¬ tional and oestrogenic actions.…”

supporting

confidence: 83%

The Effect of Mestranol and Lynoestrenol on Uterine Histamine in the Rat

ABDEL-AZIZ¹,

GHAZAL²,

DAABEES³

et al. 1975

Reproduction

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supporting

confidence: 83%

The Effect of Mestranol and Lynoestrenol on Uterine Histamine in the Rat

ABDEL-AZIZ¹,

GHAZAL²,

DAABEES³

et al. 1975

Reproduction

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“…By contrast, lynoestrenol, in the dose used, was shown to possess a weak oestrogenic activity in addition to a dominant progestational action. The weak oestrogenic activity of lynoestrenol has also been reported by several workers (Overbeek et al, 1962;Okada, Amatsu, Ishihara & Tokuda, 1964;Paulsen, 1965). It seems possible that the dominant progestational action of lynoestrenol is responsible for the failure of the appearance of excitatory a-adrenoceptors in the majority of rats treated with this steroid.…”

supporting

confidence: 61%

“…Vaginal smears were examined daily throughout the period of treatment. The dosage and duration of treatment ensured a maximal contraceptive effect (Goldzieher, Moses & Ellis, 1962;Overbeek, Madjerek & de Visser, 1962;Gardner, Gnoj, Watnick & Gibson, 1964).…”

mentioning

confidence: 99%

The Effect of Mestranol and Lynoestrenol on the Sensitivity of the Isolated Rat Uterus to the Inhibitory Action of Sympathomimetic Agents

Abdelaziz¹,

Ghazal²,

Daabees³

1974

Reproduction

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The effect of oral treatment of rats for 12 consecutive days with the contraceptive steroids, mestranol (0\m=.\08mg/rat/day) and lynoestrenol (2\m=.\5mg/rat/day), separately or in combination, on the sensitivity of the isolated spontaneously contracting rat uterus to the inhibitory action of isoprenaline, adrenaline and noradrenaline was investigated. The sensitivity to isoprenaline did not change significantly after any of the hormonal treatments. The sensitivity to adrenaline was significantly reduced after treatment with mestranol and lynoestrenol separately and together. Only mestranol treatment also resulted in a significant decrease in sensitivity to noradrenaline while the decrease after lynoestrenol or mestranol+ lynoestrenol was not significant. Treatment with only one or with a combination of the steroids resulted in the appearance of excitatory \g=a\-adrenoceptors which most probably contributed to the decrease in the sensitivity of the uterus to the inhibitory action of the sympathomimetic agents. The reactivity of the isolated rat uterus to the inhibitory action of some sym¬ pathomimetic agents depends on the types of adrenoceptors, the rate of binding, the enzymatic inactivation and the functional state of the uterus (see AbdelAziz & Bakry, 1973). After oestrogen treatment and during early pregnancy, there is a decrease in the sensitivity of the isolated rat uterus to some sympatho¬ mimetic agents (Abdel-Aziz & Bakry, 1973).The present investigation deals with the effect of treatment with two contra¬ ceptive steroids, mestranol and lynoestrenol, on the sensitivity of the isolated rat uterus to the inhibitory action of some sympathomimetic agents.Forty virgin female albino rats with a mean body weight ofl55 + 6-0g were allocated equally to four groups. The animals selected showed regular oestrous cycles. The contraceptive steroids were suspended in 0-5% (w/v) carboxymethylcellulose (CMC) and oral treatment with 0-2 ml CMC/day was con¬ tinued for 12 consecutive days. The first group received 0-08 mg mestranol/rat/ day, the second group received 2-5 mg lynoestrenol/rat/day and the third * Present address:

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“…Furthermore, it should be mentioned that the effectiveness of oral administration of progestins and estrogens in contraceptive pills (33) may involve more than the inhibition of ovulation. Their effects on egg transport may be of importance whether or not the inhibition of nidation is concerned (34)(35)(36).…”

Section: Discussionmentioning

confidence: 99%

Effects of Oral Administration of Medroxyprogesterone Acetate and Ethinyl Estradiol on the Transportation and Development of Rabbit Eggs

Chang¹

1966

Endocrinology

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Fifty-four rabbits in groups of 6 were subcutaneously injected with progesterone or fed medroxyprogesterone acetate (MPA) for 3 days either before or after artificial insemination and an ovulation-inducing injection of HCG. Feeding with progesterone (2 mg/rabbit/day) before or after ovulation, or by injection after ovulation, had no effect on the development of eggs when examined on day 6. Subcutaneous injection of progesterone or feeding with MPA at the same dose before ovulation, however, induced a complete degeneration of eggs. Oral administration of MPA before ovulation at doses less than 2 mg/rabbit/day for 3 days was progressively less effective. Fifty-six rabbits were fed ethinyl estradiol (EE) or MPA on various days before and/or after insemination, or with one compound before and the other after insemination. When examined on day 6, degeneration of eggs was observed whenever 0.05 mg/rabbit/day of EE was fed for 3 days after ovulation or MPA (2 mg/rabbit/day) for 3 days before ovulation. Although a single feeding with MPA on day -1 (the day before insemination) and a single feeding with EE on day 1 were effective, a single feeding with MPA on day -1, a single feeding with EE on day 1, or 3 feedings with EE before ovulation and 3 injections of progesterone after ovulation, all produced less egg degeneration. Fifty-two rabbits were fed MPA before ovulation or with EE after ovulation. Although the majority of eggs were fertilized and normal when examined on day 2, the rate of recovery was slightly lower, and the eggs reached the uterus sooner than in the controls. Another 50 rabbits were fed MPA before and/or with EE after ovulation and were examined on days 2, 3 and 4. In these animals the recovery rate decreased as time elapsed, egg transport was speeded, and many eggs recovered at later times were neither at the expected stage of development nor developing normally. Finally, 1-day rabbit eggs were transferred into the ampullae of the fallopian tubes of estrous rabbits treated with MPA or EE. When examined at various times, the recovery rate was very low in the recipients treated with EE after transfer. Early entry of eggs into the uterus was observed in the control recipients, in those treated with MPA before transfer, and in those treated with EE after transfer. Retention of eggs in the tubes, however, was found in the recipients treated with MPA after transfer. It is concluded that endogenous or exogenous estrogen causes rapid egg transport from the tube to the uterus, while endogenous or exogenous progesterone counteracts the estrogenic effect and slows egg transport. Administration of progesterone before ovulation or of estrogen after ovulation speeds the transport of eggs and causes their degeneration or expulsion from the uterus. {Endocrinology 79: 939, 1966)

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The Effect of Lynestrenol) on Animal Reproduction

Cited by 28 publications

References 0 publications

The Effect of Mestranol and Lynoestrenol on Uterine Histamine in the Rat

The Effect of Mestranol and Lynoestrenol on Uterine Histamine in the Rat

The Effect of Mestranol and Lynoestrenol on the Sensitivity of the Isolated Rat Uterus to the Inhibitory Action of Sympathomimetic Agents

Effects of Oral Administration of Medroxyprogesterone Acetate and Ethinyl Estradiol on the Transportation and Development of Rabbit Eggs

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