Relationship between progesterone suppression and pregnancy in rats

Evaluation of the potential sensitization of chlorogenic Acid: a meta-analysis

Chlorogenic acid (CGA) widely exists in many plants, which are used as medicinal substances in traditional Chinese medicine injectables (TCMIs) that have been widely applied in clinical treatments. However, it is still controversial whether CGA is responsible for TCMIs-related hypersensitivity. Several studies have been performed to evaluate its potential sensitization property, but the results were inconclusive. Therefore, the aim of this study was to evaluate its potential sensitization systematically using meta-analysis based on data extracted from literatures, searching databases of PubMed, EMBASE, ISI Web of Knowledge, CNKI, VIP, and CHINAINFO from January 1979 to October 2012, a total of 108 articles were retrieved by electronic search strategy, out of which 13 studies met the inclusion criteria. In ASA test, odds ratio of behavior changes was 4.33 (1.62, 11.60), showing significant changes after CGA treatment (P = 0.004). Serum IgG, serum histamine, PLN cellularity, and IgG1 AFCs were significantly enhanced after CGA treatment (P < 0.05). Totally, these results indicated that CGA could induce a positive reaction in potential sensitization, and intravenous administration of it might be a key factor for sensitization triggering, which could at least warrant more careful application of TCMIs containing CGA in clinical practices.

Effects of SCH 486757, a nociceptin-1 receptor agonist, on fertility and reproductive hormone levels in female CRL:CD®[SD] rats

BACKGROUND

SCH 486757 is a nociceptin-1 receptor agonist that was in development as an antitussive. Studies were conducted to characterize its effects on female fertility and to examine its potential modes of action.

METHODS

Female rats were administered up to 20 mg/kg SCH 486757 before/during mating through gestation day (GD) 7; female fertility and embryonic development were assessed on GD 14. In a subsequent study, pregnant rats were dosed up to 50 mg/kg SCH 486757 from GD 0 to 7. Reproductive hormones were assessed on GD 1, 3, 5, and 7, and embryonic development was assessed on GD 14. A subset of dosed dams were allowed to deliver, were subsequently re-mated, and reproductive hormones and fertility were assessed on GD 7 and 14, respectively. To determine the effects of SCH 486757 on nonpregnant rats, doses of up to 50 mg/kg SCH 486757 were administered for 4 days beginning on the day of estrus; reproductive hormones were assessed after the final dose.

RESULTS

Female rats administered ≥20 mg/kg SCH 486757 exhibited abnormal estrous cycles; decreased fertility, number of corpora lutea, and implantation sites; and increased pre- and postimplantation loss. In general, administration of SCH486757 was associated with lower luteinizing hormone (LH) progesterone (P4), and estradiol (E2) levels in pregnant rats. These effects on fertility/embryonic development and reproductive hormones exhibited reversibility post dosing. Nonpregnant rats in the 50-mg/kg group exhibited apparent decreases in P4 and E2 levels, with no apparent effects on LH values.

CONCLUSIONS

The SCH 486757-related effects on fertility and embryonic development were likely the result of decreases in P4, E2, and/or LH, rather than being due to decreased prolactin levels.

Chronic Di-n-butyl Phthalate Exposure in Rats Reduces Fertility and Alters Ovarian Function During Pregnancy in Female Long Evans Hooded Rats

Testis function in fetal and peripubertal male rats is disrupted by subchronic exposure to phthalate esters (PEs). In contrast to the male rat, it is generally held that reproduction in female rats is much less sensitive to phthalate-induced disruption. However, the current study demonstrates that oral administration of dibutyl phthalate (DBP) to female Long Evans (LE) hooded rats from weaning, through puberty, mating, and gestation disrupts pregnancy maintenance at dose levels similar to those that affect testis function in male rats. Administration of 500 and 1000 mg DBP/kg/day, but not 250 mg DBP/kg/day, to female LE rats induced midpregnancy abortions. The percentage of females delivering live pups was reduced by more than 50% at 500 mg/kg/day and by 90% at 1000 mg/kg/day in the absence of overt toxicity, whereas the ages at vaginal opening and first estrus, estrous cyclicity, and mating indices (N mated/N paired or N pregnant/N mated) were not significantly affected. On gestational day 13, prior to the stage when litters were being aborted, ex vivo ovarian hormone production was significantly decreased by in vivo DBP treatment at 500 and 1000 mg/kg/day. These results should be considered when evaluating mechanisms of reproductive toxicity for the PE because it is likely that these reproductive alterations in the female rat arise via a mode of action similar to that operative in male rats.