• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.191-200
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• 1994

The influence of hypoxanthine and ovarian steroids on the meiotic maturation process of mouse oocytes was investigated for the qualified application of culture medium in in vitro fertilization(IVF). Mouse oocytes were cultured in hypoxanthine and various ovarian steroids(progesterone, estradiol-17${\beta}$ and testosterone) and their effects on the oocyte maturation had been observed. When mouse oocytes were cultured in the various concentration(1-4mM) of hypoxanthine, meiotic maturation of cumulus cell-enclosed oocytes was inhibited by presence itself, which was a dose-dependent effect in meiotic arrest of mouse oocytes. The presence of progesterone, estradiol-17${\beta}$ and testosterone have made the mouse oocyte mature properly. Meanwhile maturation of cumulus cell-enclosed oocyte was severely inhibited by 3 hoursculture in the media of progesterone supplemented with hypoxanthine. However the continuous presence lasting 24 hours of progesterone even supplemented with hypoxanthine had got rid of the inhibition of oocytes maturation. Not only estradiol-17${\beta}$ supplemented with hypoxanthine but also testosterone supplemented with hypoxanthine exert the severe inhibition of the maturation of cumulus cell-enclosed oocytes for 3-hours culture. However the continuous presence lasting 24 hours of estradiol-17${\beta}$ and testosterone even supplemented with· hypoxanthine had relieved the inhibition of oocytes maturation. These results make us suggest that hypoxanthine inhibits the mouse oocyte maturation, particularly markedly in conjunction with ovarian steroids for short period, which indicated some sort of the synergistic inhibitory retationship between the ovarian steroids and hypoxanthine.

• Clinical and Experimental Reproductive Medicine
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• v.9 no.1_2
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• pp.55-68
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• 1982

The present investigation has been undertaken to understand the mechanism of implantation process, by demonstrating the role of ovarian steroids in connection with phosphatase activity in the differentiation of uterine endometrium for implantation. The results obtained are as followings: The differentiation of the uterine endometrial tissue was closely influenced by the ovarian steroid hormones; at first, 17${\beta}$-estradiol initiated the differentiation of the uterine luminal and glandular epithelial cells, and then progesterone induced differentiation of stromal cells, and thereby two steroids maintain decidualization of the uterine tissues. We observed that the phosphatase activities seem to be dependent upon the ovarian steroids; that is the activity showed higher level in progesterone treated group than in estradiol treated one, and the highest activity was found in the group treated with both estradiol and progesterone. Acid phosphatase showed the highest activity whereas alkaline phosphatase showed the lowest in the rat uterine endometrium during early pregnancy.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.124-131
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• 2007

There is worldwide interest in buffalo as an animal for meeting the growing demands of meat, milk and work in the developing countries. One of the major constraints to full exploitation of the productive potential of buffalo has been its inherently low reproductive efficiency as reflected by late maturity, poor expression of oestrus, silent oestrus, irregular oestrous cyclicity, seasonality in breeding, anoestrus, low conception rate, long postpartum interval, repeat breeding etc. Ovarian cyclicity is regulated by endocrine and neuroendocrine mechanisms namely hypothalamic hormones, gonadotropins and ovarian steroids. Detailed endocrine investigations are suggested with special reference to the hypothalamo-hypophysial-ovarian axis to gain a better understanding of reproduction in buffalo and to modify it to derive the maximum benefit from this animal.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.695-699
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• 1996

This experiment was to determine the effect of sialoadenectomy on the ability of the mammary gland development to response to ovarian steroids, estrogen and progesterone, stimulus in vivo. Body weights did not differ between sham-operated and sialoadenectomized mice within 0 to 18 day estradiol + progesterone (E + P) injection (p > 0.05). Sialoadenectomy reduced mammary development scores from 4.6 to 3.9 or from 4.4 to 3.8 in comparison with those of sham-operated mice for the 12 or 18 day E + P injection ($P{\leq}0.05$), however, sialoadenectomized mice with 0, 1, 3 or 6 day of E + P injection slightly decreased mammary development scores relative to those of sham-operated mice. These results indicate that the endocrine factor secreted from submandibular salivary gland appears to be required for the mammary development to respond fully to estradiol and progesterone. Similar results were obtained in the measurement of mammary DNA contents. Mammary DNA contents of sialoadenectomized mice were significantly decreased relative to those of sham-operated mice for the 6, 12 or 18 day E + P injections. Overall results suggest that salivary gland-secreted endocrine factor, presumably epidermal growth factor (EGF), was mammogenic and should interact with ovarian steroids in mammary development.

• Clinical and Experimental Reproductive Medicine
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• v.14 no.2
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• pp.149-158
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• 1987

The present investigation has been undertaken to understand the mechanism of implantation process, by demonstrating the role of ovarian steroids in the differentiation of uterine endometrium for implantation. In particular, an attempt was made to examine the activity of alkaline phosphatase (ALP) in the either luminal, stroma or endometrium tissue sites under the pseudopregnant state induced by ovarian steroid hormones. Attempt was also made to demonstrate the correlate function of ovarian steroids with the cAMP concentration and prolactin level. The higher activity of ALP in the uterine endometrium was observed on day 3. However, the higher activity of ALP in the stroma and epithelium was observed on Day 6. This study, therefore, clearly demonstrates that progesterone is consecutive effect in stroma differ entiation. The cAMP concentrations on Day 3 treated with E or P was lower than those of control. On the other hand concentration on Day 6 treated with hormones was increased than those of control. It is, therefore, concluded that the concentration of cAMP in the uterine tissue undergoing differentiation is decreased. The prolactin level of the treated groups was the lower levels than those of the control groups. It is indicated that there is no effect of ovarian steroid hormone on the prolactin synthesis in this pseudopregnant state.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.514-518
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• 1997

This study was designed to record the ovarian response towards a combined administration of heterologous buffalo FSH (buFSH) and LH (buLH) in goats. The impact of such a treatment on ovarian structures and on the plasma profile of the ovarian sex steroids (estradiol $17-{\beta}$ and progesterone) was studied. The buFSH and buLH were isolated from the buffalo pituitaries involving a procedure of ethanolic extraction, acetone precipitation followed by metaphosphoric acid - ammonium sulphate fractionation. Both gonadotrophin samples prepared were found biologically active and potent. There was an increase in the total number of follicles in the treated group ($12.66{\pm}1.24$) vis-a-vis the control group ($8.50{\pm}2.06$). However, the percentage ($51.48{\pm}6.37$) of large follicles were found reduced ($23.74{\pm}5.93$) following the treatment. Again the number of corpora lutea were observed significantly higher ($2.33{\pm}0.47C.L.$) in the treated group than (1 C. L.) in the control group. The peak plasma estradiol- $17{\beta}$ levels achieved, were much higher ($17.16{\pm}9.52pg/ml$) in the treated group, than the peak ($7.22{\pm}1.67pg/ml$) achieved in the control group. Similar trend was observed with respect to the progesterone levels (higher in the treated group). This study thus indicated that, a combined administration of heterologous buffalo FSH and LH to goats speeded up development of larger follicles nearing the ovulation stage. This population of the follicles subsequently got reduced and lead to the formation of the increased number of the corpora lutea observed in this study.

• Advances in Traditional Medicine
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• v.6 no.4
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• pp.300-305
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• 2006

Pethidine at the dose level of 0.5 mg and 0.75 mg/100 g body weight administered for 20 days to the cycling albino rats caused decrease in the ovarian weight and its protein content. The ovarian folliculogenesis in treated rats is hampered; as a result the follicles which are at the different stages of growth underwent regression. Therefore, the number of healthy follicles is reduced and atretic follicles increased. The elevated levels of ovarian cholesterol and decreased level of glycogen in the pethidine treated rats indicates the inhibition brought in steroidogenesis, which is dependent on pituitary gonadotrophins.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.469-474
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• 1995

The effects of sperific inhibitors of $3\beta-hydroxy-\Delta^5-steroid\;dehydrogenase$ $(3\beta-HSD;\;an\;enzyme\;catalyzing\;conversion\;of \Delta^5\;steroids\;to\;\Delta^4 steroids),$ cyanoketone and trilostane, on $^3H-pregnenolone$ metabolism in isolated ovarian thecal layers have been investigated in vitro. At all doses of cyanoketone $(10^{-5}\;and\;10^{-4}\;M)$ and trilostane $(10^{-5}\;and\;10^{-4}\;M)$ $(3\beta-HSD$ enzyme activity that transforms pregnenolone to $17\alpha-hydroxyprogesterone$ was inhibited in the thecal layers. Trilostane appeared to be more efficient than cyanoketone. Trilostane at doses of $10^{-8},\;10^{-7},\;10^{-6},\;and\;10^{-5},\;M/ml$ caused a dose-response inhibition of $\Delta^4$ steroids accumulation in the medium from pregnenolone, but not completely blocked the conversion of $\Delta^5\;to\;\Delta^4$ steroids.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.257-265
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• 1996

Previously, we demonstrated that estradiol (E$_2$) was produced by medium sized follicles of Rana nigromaculata and Rana dybowskii in vitro. Present experiments were carried out to determine when the growing follicles have obtained the ability to produce E$_2$. Follicles in different growth stages were isolated and cultured for 6 hours in the presence or absence of frog pituitary homogenates (FPH, 0.1 pituitary/2m1) or various steroid precursors (200 ng/2m1). levels of progesterone (P$_4$), 17 -hydroxyprogesterone (17$\alpha$-OHP), androstenedione (AD), testosterone Cr) or E$_2$ in the medium were measured by RIA. The smallest follicles failed to produce steroids, whereas the smaller follicles produced considerable amounts of steroids (211 pg/follicle), and the medium sized follicles produced a large amounts of steroids (1653 pg/follicle) in response to FPH. Addition of pregnenolone (P5) resulted in a marked increase in P$_4$ but not in other steroids by the smallest follicles whereas the treatment resulted in a marked increase in P$_4$, 17$\alpha$-OHP, AD, T and E$_2$by the smaller and medium follicles. When the amounts of steroids are calculated on the basis of unit surface area (pg/mm$_2$), the ability of the smallest follicles to produce P$_4$ from P5 was similar to those of smaller and medium sized follicles. However, the smallest follicles failed to metabolize P$_4$ to other steroids whereas the smaller and medium follicles did. Taken together, the data suggest that the smallest follicles do not response to FPH in terms of steroid production but they have capacity to convert P5 to P$_4$ and that the smaller follicles have potential to produce E$_2$ although much less efficient than medium sized follicles.

• Clinical and Experimental Reproductive Medicine
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• v.14 no.1
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• pp.43-49
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• 1987

In the present study, hormonal changes in uterine tissue and circulation were evaluated during the implantation period in rats in order to understand the mechanism by which implantation takes place. The results obtained were as follows. 1. Concentrations of serum estradiol and progesterone were significantly increased on days 4 and 5. 2. Concentration of estrogen receptor reached maximum on day 5 when implantation normally occurred in rats. On the other hand, progesterone receptor was gradually decreased, reaching the lowest on day 5. 3. Uterine PGs and cAMP concentrations were significantly increased on day 5. 4. Uterine PGs and cAMP concentrations in implant sites were significantly greater than those in non-implant sites. It is, therefore, concluded that prostaglandins and cAMP in uterine tissue as well as circulating ovarian steroid hormones were increased during the period of implantation, suggesting that these hormones might be actively involved in the process of implantation in rats.