Ovule reduction

Analysis of ESRB 7 mice showed fewer and smaller litters than wild type mice as well as abnormal vascular function and hypertension. The reduction in fertility was attributed to reduced ovarian efficiency. Mutant females had normal breast development and lactated normally. Older mutant males displayed signs of prostate and bladder hyperplasia. s -2-deficient mice furthermore display diverse regulatory defects in the function of brain, lung, and white blood cells. The results indicated that ESRB is essential for normal ovulation efficiency but is not essential for lactation, female or male sexual differentiation, or fertility. 

Reproductive studies showed that 14 pairs of mice that received 40 ppm chlordecone in the diet for 2 months before mating and during the test produced no litters, whereas 14 control pairs produced 14 first litters and 14 second litters. Further studies in mice found that infertility in chlordecone-exposed females was due to an absence or reduction in the number of ovulated oocytes. Prenatal exposure of rats has also been shown to persistently alter neurobehaviors in adults. ... 

In mice and male rats, the oral LD50 was approximately 4g/kg symptoms of toxicity were ataxia and hyperactivity followed by inactivity, loss of muscular tone, labored breathing, clonic convulsions, and death within 2-7 days. Daily administration of 132mg/kg body weight in the diet for 13 weeks decreased the fertility of CD rats 14 days at 96mg/kg altered the estrous cycle of females." In female rats 50 mg/kg injected intraperitoneally on the day of proestrus delayed ovulation and resulted in a lower fertility rate, a reduction of live fetuses, an increase in resorptions, and a slower rate of fetal development. Gavage doses in rats of... 

TCDD-exposed rats, suggesting that 2,3,7,8-TCDD inhibited the positive feedback action of 17 -estradiol at the hypothalamic-pituitary axis (Li et al. 1995a). In hypophysectomized rats, 2,3,7,8-TCDD exposure resulted in a reduction of ovulation Li et al. (1995a) suggests that this may be the result of a direct effect on the ovary, although the mechanism has not been elucidated. 

PTX-2 inhibited cytokinesis in mammalian ovulated oocytes and induced apoptosis in p53-deficient tumours both in vivo and in vitro (Chae et al. 2005). The authors found that treatment with PTX-2 influenced proteins involved in apoptosis in p53-deficient cells. PTX-2 displayed potent cytotoxity, with LC q values as low as 6.7 pg/mL, to a wide range of human cancer cell lines in vitro (Jung et al. 1995). The authors also presented evidence that PTX-2 did not block oxidation-reduction processes in the membrane or block DNA synthesis in vitro. 

Libido is greatly subject to psychosocial influences, and removal of fear of pregnancy may permit enthusiasm for the first time. It is likely that direct pharmacological effect (reduction) is rare. There is evidence that the normal increase in female-initiated sexual activity at time of ovulation is suppressed. ... 

One study su ests that lamotrigine does not alter the contraceptive efficacy or plasma levels of combined oral contraceptives. Another study found a slight reduction in levonoigestrel levels but no evidence of ovulation, however, based on this, the manufacturer says that the possibility of reduced contraceptive efficacy cannot be ruled out... 

Preliminary results of a study show that rufinamide 800 mg twice daily for 14 days decreased the AUC of ethinylestradiol 35 micrograms hy 22% and of norethisterone 1 mg by 14% in healthy women taking a combined oral contraceptive. Inhibition of ovulation was not assessed. These reductions in plasma levels of the contraceptive hormones are similar to those seen with topiramate (see Hormonal contraceptives + Antiepileptics Topiramate , below), and their clinical relevance is unknown. However, given these findings, low-dose contraceptives (ethinylestradiol 20 micrograms) may be considered unsuitable for use with rufinamide. Further study is needed. 

In guinea pigs administered shepherd s purse as 20 or 40% of the diet, no effects on fertility were observed at the 20% level at 40%, temporary infertility was observed in males and females, and a reduction in ovulation was observed. No estrogenic activity was demonstrated (East 1955). 

A rough estimate of DL induction is obtained by recording litter size alone. But ovulation rates per pregnancy show wide variation. Other sources of error would be cannibalized neonates. This method is therefore very insensitive, and even if significant reductions in litter size were found, one could not decide whether the cause was oligospermy or DL mutation. More remotely, sterility and semisterility in offspring are other manifestations of dominant mutations in surviving embryos (Cattanach, 1964). 

Earlier, evolution was mainly seen in terms of reduction from many to a few parts. We now know that this is not the case at many levels. In basal angiosperms evolution in number of all floral parts, including ovules, is flexible (Doyle and Endress,... 

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