DELAY OF IMPLANTATION IN INTACT RATS TREATED WITH PROGESTINS

1967 ◽  
Vol 54 (1) ◽  
pp. 8-18 ◽  
Author(s):  
Ehard F. Nutting ◽  
Paul B. Soliman

ABSTRACT Compounds were administered daily by the subcutaneous route to pregnant rats from day 1 of pregnancy (the day of finding sperm) to day 8, and 1 μg oestrone combined with 4000 μg progesterone from day 9–21. Animals were checked for implantation sites by laparotomy on day 8 and again on day 15, if no sites were visible on the 8th day. Autopsy was performed on day 22 of pregnancy. Delay of nidation was produced with 6α-methylprogesterone (ED50 = 3000 μg), 17α-acetoxy-6α-methylprogesterone (ED50 = 720 μg) and its 21-fluoro (ED50 = 470 μg) and 6-dehydro-21-fluoro (ED50 = 3500 μg) derivatives, and 17α-ethyl-19-nortestosterone (ED50 = 3200 μg), but not with progesterone, 17α-acetoxyprogesterone, or 17α-acetoxy-6-dehydro-6-methylprogesterone. Foetal body weights in not delayed groups given 17α-acetoxy-6α-methylprogesterone (> 500 μg) and its 6-dehydro-21-fluoro analogue were much smaller than in control rats indicating the occurrence of additional partial delays of short duration undetectable by laparotomy on the 8th day. The number of implantation sites was reduced with 17α-ethyl-19-nortestosterone (> 500 μg/day) but not with any of the other compounds. The implantation rate achieved with a particular dose of a compound was similar in groups in which implantation was delayed ('delayed') and not delayed ('nondelayed'). In another study implantation occurred spontaneously within 8 days after cessation of all steroid treatments. The data are discussed in terms of a possible mechanism of action involving the development of an oestrogen deficiency in the animal resulting indirectly from the suppression of production or release of gonadotrophin from the pituitary gland.

1964 ◽  
Vol 45 (4_Suppl) ◽  
pp. S139-S153 ◽  
Author(s):  
K. Junkmann ◽  
F. Neumann

ABSTRACT Experiments are described dealing with the mechanism of action of 6-chloro-Δ6-1,2α-methylene-17α-hydroxyprogesterone-acetate with regard to its anti-masculine effect on male rat foetuses, when administered to pregnant rats. It was shown that a marked direct anti-androgenic effect due to a competitive action on androgen receptors within the target organs, is probably the explanation of the mechanism of action. It was further shown that an oestrogenic effect or an appreciable inhibition of the pituitary gland respectively, can be ruled out as causative factors in the mechanism of action.


Zygote ◽  
2021 ◽  
pp. 1-7
Author(s):  
Stéphanie Ouabo Meguem ◽  
Landry Lienou Lienou ◽  
Marie Stéphanie Chekem Goka ◽  
Richard Simo Tagne ◽  
Didiane Mefokou Yemele ◽  
...  

Summary Dicliptera verticillata is a medicinal plant traditionally used in western Cameroon to cure female infertility. This experiment was designed to assess the effects of the aqueous extract of Dicliptera verticillata (AEDv) on fertility and gestation in female rats. Oral increasing doses of AEDv were administered to immature female rats over 20 d. After this time, some animals were mated with fertile males and some fertility parameters were assayed; the other animals were euthanized for preliminary toxicity parameters analysis. The effects of AEDv on the different stages of gestation were assayed on selected animals previously controlled for estrous cycle regularity and mated. AEDv led to an increase in serum, uterine and ovarian proteins as well as in ovarian and uterine weights (P < 0.05) in immature female rats. Hepatic proteins significantly decreased (P < 0.01) in high dose-treated animals (50 and 100 mg/kg) compared with controls. The number of implantation sites and the fertility rate were significantly lower (P < 0.05), while the antifertility activity increased significantly (P < 0.05) in treated rats compared with controls. When administered from the 1st to the 5th day of pregnancy, AEDv led to a decrease of more than 60% in the implantation rate in high dose-treated rats (50, 100, and 400 mg/kg). From the 6th to the 9th day, the implantation, gestation rates and the number of fetuses decreased significantly in all treated groups. From the 11th to the 20th day, a 50% resorption and decrease in gestation rate were reported in 50 mg/kg dose-treated animals. AEDv possesses weak contraceptive and abortifacient effects during pregnancy.


2019 ◽  
Vol 53 (3) ◽  
pp. 139-145
Author(s):  
Tolulope Oyesola ◽  
Bolanle Iranloye ◽  
Olufeyi Adegoke

AbstractObjective. This study was designed to investigate the effect of sublethal doses (10, 60, and 120 mg/kg of pirimiphos-methyl on implantation and pregnancy in female Sprague-Dawley rats. Pirimiphos-methyl is a pesticide widely used worldwide, especially in Africa to protect food against pests and has gained widespread acceptance.Methods. Pregnant Sprague-Dawley rats used for this study had access to food and water ad libitum and were divided into a control group and three experimental groups based on dose of chemical given. The pregnant rats were given pirimiphos-methyl orally on days 1–5, 1–7, 7–18th day of gestation and from day 1 to term. Implantation studies were carried out on days 6 and 8 of pregnancy, while the fetal parameters were ascertained on day 19 of pregnancy and at term. Serum levels of progesterone and estradiol were measured on days 6, 8 and 19 of pregnancy.Results. Sublethal administration of pirimiphos-methyl showed decreased number of implantation sites on days 6 and 8, fetal weight, crown-to-rump length, length of umbilical cord and placenta weight (day 19), birth weight, litter size and total number (at term) in rats administered with pirimiphos-methyl when compared with control.Conclusion. Administration of pirimiphos-methyl resulted in a reduced implantation rate due to decreased uterine receptivity caused by an imbalance in the level of estradiol and progesterone and impaired reproductive outcome during pregnancy.


1968 ◽  
Vol 19 (03/04) ◽  
pp. 383-388 ◽  
Author(s):  
R Losito ◽  
C. A Owen ◽  
E. V Flock ◽  

SummaryThe metabolism of vitamin K1- 14C and menadione-14C (vitamin K3-14C) was studied in normal and hepateetomized rats. After the administration of menadione, about 70% of the 14C was excreted in the urine in 24 hrs in both types of rats. Two urinary metabolites were identified by enzymatic hydrolysis: one a glucuronide and the other a sulfate of reduced menadione. Thus, the liver is not necessary for the metabolism of menadione. In the vitamin K1 studies, the intact rats excreted only 10% of the 14C and the hepatectomized rats excreted less than 0.5%. The retention of vitamin K1 may explain its superiority over menadione as an antidote for overdosages of oral anticoagulants.


1995 ◽  
Vol 7 (1) ◽  
pp. 51 ◽  
Author(s):  
C O'Neill

The effects of a number of platelet-activating factor (PAF)-antagonists on embryo implantation were investigated. Mice were treated from Day 1 to Day 4 of pregnancy with three defined PAF-antagonists: SRI 63 441, BN 52021, and WEB 2086. Necroscopies were performed on Day 8 and the number of implantation sites, the implantation rate (number of implanted embryos compared with the number of corpora lutea) and the proportion of animals pregnant were determined. Each agent caused a reduction in the number of implantation sites at relatively low doses. The dose that had a maximum contragestational effect was 40 micrograms, 10 micrograms and 10 micrograms (per 30 g bodyweight per day) for SRI 63 441, WEB 2086 and BN 52021 respectively. This contragestational effect was completely lost at twice (SRI 63 441), five times (WEB 2086) and ten times (BN 52021) the most effective dose. Treatment with WEB 2086 on the day of implantation (Day 4) by intraperitoneal injection or instillation into the uterus only did not significantly reduce the implantation rate and neither did treatment after implantation (Days 5-8). The results show that the pharmacology of PAF-antagonists in early pregnancy is not simple. An understanding of the actions of these agents in early pregnancy will require a detailed knowledge of their pharmacokinetics, pharmacodynamics and targets of action in early pregnancy.


1963 ◽  
Vol 205 (3) ◽  
pp. 453-456 ◽  
Author(s):  
Philip D. Gollnick

Two groups of male albino rats of the Sprague-Dawley strain, with average initial body weights of about 265 g, were trained for 22 weeks on an exercise program of swimming one-half hour daily in water at 35 C. One trained group was fed a normal diet containing 18% casein. The other trained group received an isocaloric diet containing 1% cholesterol which was designed to produce hypercholesteremia. Two nonexercised groups, one fed the normal and the other the 1% cholesterol diet, served as controls. The adrenals and heart ventricles of both trained groups were larger than their respective controls. Exercise had no hypocholesteremic effect on the sera of either trained group. Fat and cholesterol accumulation in the livers of rats fed the 1% cholesterol diet were not affected by training, but training significantly lowered the fat and cholesterol of the livers of the normal rats.


2010 ◽  
Vol 25 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Vinicius von Diemen ◽  
Manoel Roberto Maciel Trindade

PURPOSE: Determine the effects of the MSG (monosodium glutamate) in the offspring of pregnant rats through the comparison of the weight, NAL (nasal-anal length) and IL (Index of Lee) at birth and with 21 days of life. METHODS: Pregnant Wistar rats and their offspring were divided into 3 groups: GC, G10 and G20. Each of the groups received 0%, 10% and 20% of MSG, respectively from coupling until the end of the weaning period. RESULTS: Neither weight nor NAL were different among the groups at birth. The group G20 at birth had an IL lower than the group GC (p<0,05) and with 21 days of life presented weight and NAL lower than the groups G10 and this lower than the GC (p<0,01). Otherwise the G20 at 21 days of life had the IL similar to the other two groups. The weight profit percentage from birth to the 21st day of life was lower in the G20 regarding the other two groups (p<0,01). The G20 had a NAL increase percentage from birth to the 21st day of life lower than the G10 and this lower than the GC (p<0,01). CONCLUSIONS: MSG presented a dose-dependent relation in the variables weight and NAL. It caused a decrease in the growth pattern as well as in the weight gain pattern until the 21st day of life. The IL of the group 20% had an increased in relation to the control group after 3 weeks of follow up.


1980 ◽  
Vol 94 (1) ◽  
pp. 95-104 ◽  
Author(s):  
G. J. Rowlands

SummaryBlood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.


2015 ◽  
Vol 4 (4) ◽  
pp. 221-223
Author(s):  
Alemu Tadesse Feroche ◽  

The practice of traditional medicine for the control of fertility in most part of South Western Ethiopia is based on the uses of plant medicine for many years. The present study was carried out in female albino rat to explore the abortifacient activity of the Rumex steudelli roots. Pregnant rats weighing 140- 200 g were randomized into 7 groups. Rats were laprotomised on 10th day of pregnancy and the two horns of uteri were examined to determine the implantation sites. The administration of 400 mg/kg body weight of the aqueous extract of Rumex steudelli resulted in 95% abortion. The 200 and 400 mg/kg body weight alcoholic extract showed 100% fetus abortion. The phytochemical screening of the roots of Rumex steudelli revealed the presence of flavonoids, phenolics, alkaloids, steroids, tannins and saponins.


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