Pregnancy Maintenance in Ovariectomized Rats with 16<i>α</i>, 17<i>α</i>Dihydroxyprogesterone Derivatives and Other Progestogens

Lerner, Leonard J.; Brennan, David M.; Yiacas, Euripides; Dephillipo, Michael; Borman, Aleck

doi:10.1210/endo-70-2-283

Cited by 26 publications

(8 citation statements)

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“…To maintain the pregnancy in rats ovariectomized on Day 8, Lerner et al (1962) had to inject progesterone in doses as high as 20 mg/day because oestrogen was not also given, but if oestrogen was co-injected, the progesterone requirement was lower. In our study, an adequate dose of oestro¬ gen was injected and different doses of progesterone were administered to determine the minimum progesterone concentrations required.…”

Section: Discussionmentioning

confidence: 99%

“…Progesterone used in the ovariectomized rats to maintain the pregnancy in various studies ranged from 3 to 20 mg/day. Lerner et al (1962) suggested that the optimum sub¬ cutaneous dose to maintain the pregnancy in rats ovariectomized on Day 8 of pregnancy was 20 mg/day. Tamada & Ichikawa (1980) injected only 4 mg progesterone/day plus 200 ng oestradiol/ day to rescue the fetuses of Day-14 pregnant ovariectomized rats.…”

Section: Introductionmentioning

confidence: 99%

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Critical progesterone requirement for maintenance of pregnancy in ovariectomized rats

Arkaravichien

Kendle²

1990

Reproduction

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The minimum progesterone concentration required to maintain the pregnancy was studied by varying doses of progesterone given subcutaneously to rats ovariectomized on Day 8 of pregnancy. Injecting 3 mg progesterone plus 200 ng oestradiol benzoate daily provided serum progesterone values between 25.4 +/- 7.0 and 35.2 +/- 6.2 ng/ml throughout Days 10-19 which were significantly lower than normal levels (P less than 0.05), but resulted in 93.6% of fetal survival on Day 19 which was not significantly different from 93.3% in the control group. Injecting 2 mg progesterone plus 200 ng oestradiol benzoate daily gave progesterone values between 13.2 +/- 4.6 and 19.0 +/- 6.2 ng/ml and could not maintain fetal viability to Day 19 (14.2%, P less than 0.05 compared with control group). Critical times to supplement progesterone in rats ovariectomized on Day 8 or Day 15 were studied by varying the time of progesterone implantation after ovariectomy. Progesterone implants were administered 8, 12 and 24 h after ovariectomy on Day 8 and 24, 36 and 48 h after ovariectomy on Day 15. On Day 8, progesterone replacement could be delayed to 8 h but not 12 h, while on Day 15, progesterone replacement could be delayed up to 36 h but not 48 h after ovariectomy without affecting fetal survival.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Critical progesterone requirement for maintenance of pregnancy in ovariectomized rats

Arkaravichien

Kendle²

1990

Reproduction

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“…In ovariectomized rats, 20 mg progesterone injected subcutaneously each day maintains preg nancy [23]. 6 intact rats were each injected with 20 mg progesterone B.P.…”

Section: Methodsmentioning

confidence: 99%

A Study to Compare the Influence of Suckling and Hormones on Nucleolar Activity of Supraoptic and Paraventricular Neurones of Lactating Rats

Russell¹

1982

Neuroendocrinology

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The experiments were designed to investigate the possible role of ovarian hormones in causing increased synthesis by neurones of the supraoptic (SO) and paraventricular (PV) nuclei previously found during pregnancy and lactation. Changes in the dry mass of nucleoli of these neurones were measured to indicate their synthetic activity. When a normal suckling stimulus was applied only after a delay of 7 days post-partum the nucleolar changes in PV and SO neurones that followed were similar to those that occur normally when a litter is suckled from birth; these changes thus do not depend on the hormonal state of late pregnancy or early lactation. After unilateral nipple line ablation prior to pregnancy nucleolar dry mass of PV and SO neurones increased bilaterally in a subsequent lactation. These results do not distinguish bilateral distribution of the milk ejection pathway from the action of hormones on PV and SO neurones. Nucleoli of SO and PV neurones in virgin rats were larger after treatment with a large dose of oestradiol for 5 days, but were not affected by ovariectomy, progesterone treatment or by the stage of the oestrous cycle. It is concluded that increased synthetic activity in SO and PV neurones during lactation depends upon the suckling stimulus rather than on changes in secretion rates of ovarian hormones; oestradiol may cause the nucleolar changes in PV and SO neurones seen at the end of pregnancy.

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“…In the early 1960s, Lerner et al showed that it maintained pregnancy in ovariectomized rats, without exerting virilizing effects on female fetuses [4]. In the early 1960s, Lerner et al showed that it maintained pregnancy in ovariectomized rats, without exerting virilizing effects on female fetuses [4].…”

Section: Introductionmentioning

confidence: 99%

Dihydroxyprogesterone acetophenide 150 mg + estradiol enantate 10 mg as monthly injectable contraceptives

González¹,

Aguirre²,

Rodríguez³

et al. 1996

Adv Contracept

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A survey among users and health personnel participating in the Salvadorian Social Security Institute (ISSS) Family Planning Program revealed interest in including a monthly preparation for injection as a contraceptive method offered by this Institution. The formulation containing dihydroxyprogesterone acetophenide (DHPA) 150 mg + estradiol enantate (E2EN) 10 mg was chosen for conducting an open and prospective study of efficacy and tolerability. Between January 1992 and March 1994, 7054 women were treated with this product for a total of 60010 months. A sample composed of 4505 women treated at this Institution confirmed that average users are young, have one or two children, do not show a particular geographical distribution and choose the monthly injection instead of oral contraceptives as the first contraceptive method or for the puerperium. The study formulation showed a high efficacy (Pearl Index: 0.018) and tolerability (general withdrawal rate throughout the study: 27.09%). The most frequent adverse events included bleeding disorders, headache and mastalgia; their incidence decreased spontaneously from the sixth month (3.9%), reaching 0% after two years. Treatment was discontinued due to adverse events in 3.47% of women. No significant bodyweight or systolic and diastolic blood pressure alterations were observed. Based on these results, the monthly injectable contraceptive was included in the basic product list at ISSS.

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Pregnancy Maintenance in Ovariectomized Rats with 16α, 17αDihydroxyprogesterone Derivatives and Other Progestogens

Cited by 26 publications

References 0 publications

Critical progesterone requirement for maintenance of pregnancy in ovariectomized rats

Critical progesterone requirement for maintenance of pregnancy in ovariectomized rats

A Study to Compare the Influence of Suckling and Hormones on Nucleolar Activity of Supraoptic and Paraventricular Neurones of Lactating Rats

Dihydroxyprogesterone acetophenide 150 mg + estradiol enantate 10 mg as monthly injectable contraceptives

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