• Korean Journal of Animal Reproduction
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• v.19 no.2
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• pp.141-145
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• 1995

The effect of splenectomy on the concentration of progesterone in pregnant wistar rats showing 4-day regular estrous cycles more than two cycles were investigated. The day after mating with the same male animal was designated day 0 of pregnancy. Splenectomy was conducted on day 0 (early-S), 6 (middle-S) and 13 (late-S) of pregnant rat, respectively. Blood sample were collected at day 1, 7, 14 and 21 of pregnancy. Concentraton of serum progesterone was determined by emzyme-linked immunosorbent assay (ELISA) using specific antibodies and emzyme conjugate(progesterone peroxidase labeled). In normal pregnant rats, serum progesterone concentrations were increased significantly (P<0.05) on day 7 and 14 of pregnancy compared with on day 1 of pregnancy and then dramatically decreased on day 21. However in early and middle splenectomized rats, progesterone concentrations were significantly (P<0.05) decreased on day 7 and 14 of pregnancy compared with same day of normal rats. These observations indicate that luteotropic action and steroidogenesis by corpus luteum of ovary may be regulated by splenocytes in rat.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1399-1405
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• 2013

The present study focused on establishing the effects of interferon-gamma (IFN-${\gamma}$) on interleukin-18 (IL-18) expression patterns and pregnancy outcomes in pregnant rats. Pregnant rats at the post-implantation stage were randomized into control, low IFN-${\gamma}$ (L-IFN-${\gamma}$) and high IFN-${\gamma}$ groups (H-IFN-${\gamma}$) that received normal saline, 100 IU/g of IFN-${\gamma}$ and 500 IU/g of IFN-${\gamma}$ vaginal muscular injection, respectively. The effects of IFN-${\gamma}$ on IL-18 expression and pregnancy outcomes were assessed systematically using several methods, including immunohistochemistry streptavidin-perosidase (SP), image pattern analysis, enzyme-linked immune-sorbent assay (ELISA), whole blood count (WBC) count, microscopy and visual observation. IL-18 was detected in the uteri of all pregnant rats, and mainly distributed in the endometrium, decidual cells, vascular endothelium and myometrium. Immunohistochemistry and image pattern analyses revealed significantly lower IL-18 expression in the H-IFN-${\gamma}$ group compared to the L-IFN-${\gamma}$ and control groups (p<0.01), indicating that high doses of IFN-${\gamma}$ induce downregulation of IL-18 in the uterus of pregnant rats. ELISA results disclosed that IL-18 expression in peripheral blood of the H-IFN-${\gamma}$ group was lower than that of the L-IFN-${\gamma}$ group (p<0.05), and significantly reduced compared to the control group (p<0.01). Moreover, the number of peripheral leukocytes in the H-IFN-${\gamma}$ group was significantly higher than those in the control and L-IFN-${\gamma}$ groups (p<0.01). Morphology analysis showed no evident differences between the L-IFN-${\gamma}$ and control groups. However, for the H-IFN-${\gamma}$ group, uterine mucosa bleeding, necrosis and excoriation were observed using microscopy. Visual observation revealed marroon, swelling, crassitude and no embryo in the uterus, which are obvious indicators of abortion. These results indicate that IFN-${\gamma}$ plays a regulatory role in IL-18 expression in the uterus and peripheral blood of pregnant rats at the post-implantation stage. Moreover, high levels (500 IU/g) of IFN-${\gamma}$ influence normal pregnancy at the early stages in rats by downregulating IL-18 expression in the uterus and peripheral blood and increasing the number of peripheral leukocytes, consequently triggering termination of pregnancy.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.859-866
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• 2007

The main objective of this study was to investigate the effects of exercise on serum insulin and leptin levels and GLUT-4 and VAMP-2 in skeletal muscles from the pregnant rats. F344 rats were randomly divided into four groups (n = 15 in each group): control group (CG), pregnant group (PG), pregnant running group (PR), and pregnant swimming group (PS). From the 15th day of pregnancy, animals in the running group were forced to run on treadmill for 30 min with a light intensity, while those in the swimming group were forced to swim in swimming pool for 10 min once a day for 6 consecutive days. The present result demonstrated that in pregnant rat group, serum insulin levels significantly in-creased and leptin levels significantly decreased. Skeletal GLUT-4 and VAMP-2 protein expression was significantly decreased in pregnant rats compared to non-pregnant rats. However, matenal running during gestational period alleviated pregnancy-induced changes in plasma insulin and leptin levels, and it significantly enhanced skeletal GLUT-4 and VAMP-2 protein expression. From those results, it can be suggested that running exercise during gestational period may improve glycemic control by up-regulating GLUT-4 and VAMP-2 protein expression.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.319-330
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• 1995

The influence of normal late pregnancy on insulin action and insulin secretion was studied in the Sprague-Dawley female rats. On 20th day after mating, intravenous glucose tolerance test(IVGTT) was performed in non pregnant control and pregnant rats. As results of IVGTT, glucose disappearance rate was not significantly different in both groups, but secretory response of insulin was significantly(p<0.05) increased in pregnant rat. And the ratio of insulin/glucose was significantly higher in pregnant rats, which means existence of insulin resistance. These insulin resistance was overcomed by increased secretory response of pancreatic insulin. Insulinogenic index(${\Delta}$ insulin/glucose - 5 min) was highly significantly (r=0.62, p<0.01) correlated with progesterone concentration. Glycogen level and amounts of $^{14}C$-glucose incorporated into glycogen after IVGTT were significantly(p<0.05) decreased in the liver, but were not changed significantly in soleus. Glycogen synthase activity of soleus and liver was not differ significantly in the both groups. Insulin binding at varying concentrations of insulin to crude membrane of pregnant liver was not significantly different from control. In conclusions, although these pregnant rats were normal glucose tolerance due to increased secretory response of insulin, that was correlated with progesterone concentration, pregnant rat had insulin resistance. The mechanisms of insulin resistance were not related to defect of insulin binding phase and glycogen synthase, but suggest pre-receptor and/or postreceptor phase.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.657-666
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• 2003

The present study was undertaken to evaluate the potential adverse effects of 2-BP on pregnant dams and embryo-fetal development after maternal exposure during the gestational days (GD) 6 through 19 in Sprague-Dawley rats. The test chemical was administered subcutaneously to pregnant rats at dose levels of 0, 375, 750 and 1250 mg/kg/day. During the test period, clinical signs, mortality, body weights and food consumption were examined. All dams were subjected to caesarean section on GD 20 and their fetuses were examined for external, visceral and skeletal abnormalities. At above 750 mg/kg, toxic effects including signs of toxicity, suppressed body weight, decreased gravid uterine weight and reduced food intake were observed in pregnant dams. An increase in the fetal deaths, a decrease in the litter size, a reduction in the fetal body weight and an increase in the incidence of fetal morphological alterations were also found. There were no adverse effects on either pregnant dams or embryo-fetal development at a dose level of 375 mg/kg. These results suggest that a 14-day subcutaneous dose of 2-BP is embryolethal and teratogenic at above 750 mg/kg/day in pregnant rats. In the present experimental condition, the no-observed-adverse-effect level of 2-BP is considered to be 375 mg/kg/day for dams and embryo-fetuses, respectively.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.109-114
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• 2004

The effect of Human Menopausal Gonadotropin(hMG) on the implantation, pregnancy, and the concentration of plasma progesterone were studied in pregnant rats. HMG 75 or 150 IU were administered once on day 1, 2, 3, 4, 9, 12 or 14 of gestation, respectively. Rats were autopsied on day 7 or 18. A single dose of hMG prevented implantation and terminated pregnancy in all of the rats by injecting on either day 1 or day 2 and this abortifacient action was effective 82-98% of pregnant rats on day 3 or 4 and 14-20% on day 9 or 12. Administration of hMG had no effect on termination of pregnancy on day 14. Plasma progesterone concentration by injecting hMG on day 1, 2, 3 or 4 were very decreased.

• Journal of Society of Preventive Korean Medicine
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• v.11 no.2
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• pp.159-174
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• 2007

Introduction : The experiments was undertaken to evaluate the effects of herbal medicine, Sibjeondaebotang, Yugmijihwangtang, in pregnant rats and fetuses. Female Sprague-Dawley rats were orally administered with the Sibjeondaebotang, Yugmijihwangtang at dose of 5mg/kg/day for 20 days. Pregnant rats were sacrificed at 20th day of gestation, and observed internal and reproductive organs. Approximately live fetuses in the 20th day of gestation were randomly selected and fixed in 95% ethanol. To observe skeletal malformations, fetuses were stained with alcian blue and alizarin red S. Effect on pregnant rats : Maternal body weight of Sibjeondaebotang, Yugmijihwangtang treated group has a tendency to increase compared to that of control group. There were no significant difference in internal and reproductive organs. There were no significant changes between two groups in blood chemistry and hematological values. There were no significant changes in number of corpus luteum, implantation, live fetuses and implantation rate, delivery rate, and sex ratio. But Yugmijihwangtang administered group showed higher early resorption rate than the control group(p<0.05). Also Sibjeondaebotang administered group showed higher late resorption rate than the control group(p<0.05). From the sex ratio, number of females, bigger than number of males in the control group, and more males than females in Yugmijihwangtang administered group(p<0.05).

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.212-219
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• 2003

The effect of GnRH and/or hCG on the implantation, pregnancy, and the concentration of plasma estradiol and progesterone were studied in pregnant rats. GnRH 50, or 100ug and/or hCG 50 or 100 IU were administered once on day 2 or 9 of gestation, respectively. Rats were autopsied on days 8 or 16. Administration of GnRH on day 2 did not induce the prevention of implantation and termination of pregnancy but was able to induce termination of pregnancy administering on day 9. Administration of hCG induced delayed implantation on day 2 and termination of pregnancy on day 2 and 9. Administration of GnRH concomitant with hCG had no effect on prevention of implantation on day 2 but induced termination of pregnancy with a very increased fetal resorption on day 2 and with a moderate increased fetal resorption on day 9. Administration of GnRH concomitant with hCG on day 2 induced more increased termination of pregnancy compared to injection of GnRH or HCG and opposite result was observed on day 9. Plasma estradiol and progesterone concentrations by administering GnRH and/or hCG had no effect on the termination of pregnancy the pregnant rats.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.115-115
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• 2004

• Toxicological Research
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• v.24 no.4
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• pp.263-271
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• 2008

Recently we reported that 2-bromopropane (2-BP) has maternal toxicity, embryotoxicity, and teratogenicity in Sprague-Dawley rats. The aims of this study are to examine the potential effects of 2-BP administration on pregnant dams and embryo-fetal development, and to investigate the effects of metabolic activation induced by phenobarbital (PB) on developmental toxicities of 2-BP. Pregnant rats received 1000 mg/kg/day subcutaneous 2-BP injections on gestational days (GD) 6 through 10 (Group II and Group IIII) or 11 through 15 (Group IV). Pregnant rats in Group III received an intraperitoneal PB injection once daily at 80 mg/kg/day on GD 3 through 5 for induction of the liver metabolic enzyme system. Control rats received vehicle injections only on GD 6 through 15. All dams underwent caesarean sections on GD 20 and their fetuses were examined for external, visceral, and skeletal abnormalities. Significant adverse effects on pregnant dams and embryo-fetal development were observed in all the treatment groups, and the maternal and embryo-fetal effects of 2-BP observed in Group II were higher than those seen in Group IV. Conversely, maternal and embryo-fetal developmental toxicities observed in Group III were comparable to those seen in Group II. These results suggest that the potential effects of 2-BP on pregnant dams and embryo-fetal development are more likely in the first half of organogenesis (days $6{\sim}10$ of pregnancy) than in the second half and that the metabolic activation induced by PB pre-treatment did not modify the developmental toxic effects of 2-BP in rats.