• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.217-228
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• 1995

The study was designed to investigate the effects of progesterone on the reproductive system. This investigation was performed by immunohistochemical methods using anti-bromodeoxyuridine-antibody following bromodeoxyuridine(Brdur) injection for labeling proliferating cells in the uterus and ovary of rats. Sixteen female rats(Wistar), weighing initially 300g, were randomly allotted into ovariectomized and unovariectomized large groups. These two large groups were subdivided into three subgroups of control, 3-day and 6-day groups, respectively. 3-days and 6-days group were injected with 1mg of progesterone/rat/day for 3 or 6 days, respectively. In gross findings, the uterus of ovariectomized groups markedly atrophied, and were not hypertrophied by progesterone injection for 3 days or 6 days and the uterus of unovariectomized groups also were not hypertrophied. Labeling index(LI, %) was measured by counting the number of Brdur-positive cells from 300 to 3,000 cells per layer in the uterus tissue. The average LI of the uterus in unovariectomized groups was higher than that of ovariectomized groups. The subgroups with higher LI in unovariectomized groups were ordered as 6-day group, 3-day group. So progesterone considerably effected to the proliferating of the cells in the uterus of unovariectomized groups. The layers with higher LI in the uterus wall were ordered as the functional zone of endometrium, epithelial layer of endometrium, basal zone of endometrium, myometrium and perimetrium. The cell types with higher LI in the uterus of unovariectomized groups were ordered as the surface epithelial cells, stromal cells, glandular epithelial cells and muscle cells. Growing follicles with proliferating cells from secondary and tertiary follicles in the ovary of unovariectomized groups appeared to be 37.66% in control group, 39.23% in 3-day groups, 39.47% in 6-day groups. Mature follicles in the ovary were more number in control group than those in 3-day groups but not appeared in 6-day groups. So progesterone not nearly effects to the number of the growing follicles but appeared to be related to suppression of the development and protrusion of the mid-tertiary and mature follicles on the ovary surface. The cell types with higher LI in the ovary of unovariectomized groups were respectively ordered as granulosa cells, theca interns cells in secondary follicles; theca interna cells, granulosa cells, theca externa cells in tertiary follicles; fibroblasts, theca in terns cells in atretic follicles; fibroblasts, luteal cells in corpus luteum.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.369-375
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• 2003

The ultrasonography was performed in 77,924 subestrous dairy cows from 680 dairy farms at 57 districts. The cows were examined for confirmation of resumption of ovaries and uterus after 30 days postpartum, for early pregnancy diagnosis after 30 days post-insemination, confirmation of pregnancy at 8 month post-insemination, and for diagnosis of reproductive dysfunctions, respectively. The results of reproductive examination by ultrasonography in 77,924 dairy cows were ovarian disorders 35,452 (46.8%), uterine disorders 10,721 (13.8%), pregnancy and pregnant failure 24,044 (30.8%), adhesion of reproductive tracts 167 (0.2%), freematins 13 (0.01%) and others 6,527 (8.4%) cows, respectively. The 13,732 (49.6%) cows out of 27,694 cows were treated for silent heat or error of estrus detection, 3,473 (12.5%) cows for follicular cysts, 815 (3.0%) cows for luteal cysts, 606 (2.2%) cows for inactive ovaries, 4 (0.01%) cows for granulosa cell tumors, and 6,455 (23.3%) cows for endometritis, respectively. The indices of reproductive efficiencies before (2001-08-10) and after (2003-07-20) periodical examination of reproductive status were as follows; the mean intercalving interval were shortened from 471 days to 383 days, the mean interval calving to conception were shortened from 187 days to 99 days, the mean interval calving to first service were shortened from 105 days to 67 days, the mean cows showing heat by 60 days postpartum were increased from 33% to 89%, the mean conception rate to first service were increased from 43% to 68%, and the mean service per conception were shortened from 2.6 times to 1.8 times, respectively. These results suggest that periodical examination of reproductive status would be useful for the improvement of the reproductive performance in dairy cows.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.435-445
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• 1990

Gonadotropin releasing horrnone (GnRH) is known to be extrahypothalamically localized with a broad range including gonad. It remains, however, unknown whether GnRH is locally synthesized in the gonad. The present srudy aims to identity expression and cellular localization of GnRH-Iike mRNA and immunoreactive GnRH in the rat gonad. GnRH radioimmunoassay and chromatographic extracts on G-50 sephadex column showed that rat gonadal extracts contained a substantial amount of immunoreactive GnRH similar to the hypothalamic and synthetic GnRH. Although a wide distribution of immunostainable GnRH-like molecule with different cell types in the rat ovary was observed, the major cell population hybridized with GnRH probe appears to be granulosa. theca cells and corpus luteum. Immunoreactive GnRH-Iike peptides were distributed m various regions of testis, including spermatogenic cells, Sertoli cells and Leydig cells. In situ hybridization revealed that positive signals of GnRH-Iike mRNA were predominandy present in Sertoli cells within some seminiferous tubules, but absent in the outside of seminiferous tubules in the testis. This study clearly demonstrated that GnRH-Iike molecule present in the rat gonad may be resulted from the local synthetic machinery of GnRH supporting the notion that this peptide may act as autocrine and/or paracrine role in intra-gonadal communication.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.603-613
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• 1995

Plasma progesterone($P_4$) assay has been introduced to apply to the differential diagnosis of reproductive disorders and the monitoring of responses of ovarian dysfunction to $PGF_2{\alpha}$ or GnRH treatment in the 204 postpartum and postinsemination subestrus dairy cows. 1. The incidence rate of reproductive disorders in 204 subestrus cows, diagnosed by palpation per rectum and plasma $P_4$ determination using 'Two sample test'(Day 0+Day 10) were as follows; silent heat or error of estrus detection 110(53.9%), persistent corpus luteum 26(12.7%), follicular cyst 16(7.8%), inactive ovary 12(5.9%), luteal cyst 11(5.4%), granulosa cell tumor of ovary 1(0.5%), fetal mummification 1(0.5%), endometritis 15(7.4%) and pyometra 12(5.9%), respectively. 2. After the $PGF_2{\alpha}$ treatment to the 76 cows with silent heat or error of estrus detection, persistent corpus luteum, or luteal cyst, plasma $P_4$ concentrations at day 3 post treatment using 'Two sample test'(Day 0+Day 3) remained low(<1.0ng/ml) in all 76 cows. Therefore all 76 cows responded positively to $PGF_2{\alpha}$ treatment. Seventeen cows with follicular cyst or inactive ovary were treated with GnRH. All 7 cows with follicular cyst and 4 cows with inactive ovary remained high($${\geq_-}1.0ng/ml$$) a plasma $P_4$ concentrations at day 12 post treatment using 'Two sample test'(Day 0+Day 12), but 6 cows with inactive ovary remained low(<1.0ng/ml) a plasma $P_4$ concentrations. Therefore all 7 cows with follicular cyst and 4 cows with inactive ovary responded positively, but 6 cows with inactive ovary responded negatively to GnRH treatment. 3. The mean days from treatment to first service, number of cows conceived on first service(%), mean number of services per conception, mean days from initial treatment to conception, and mean number of cows conceived by 100 days post treatment(%) were 5.0 and 26.2 days, 45(59.2%) and 6(35.3%) cows, 1.5 and 1.7 services, 13.6 and 22.6 days, and 62(81.6%) and 9(52.9%) cows in group of $PGF_2{\alpha}$ and GnRH treatment, respectively. These results indicated that plasma $P_4$ assay was practical as an aid to diagnosing reproductive disorders and to monitoring responses of ovarian dysfunction to $PGF_2{\alpha}$ and GnRH treatment in subestrus cows.

• Proceedings of the KSAR Conference
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• 2000.10a
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• pp.10-12
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.357-364
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.217-223
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• 2006

This study was carried out principally to obtain the basic data for the improvement of the reproductive performance and production using plasma progesterone assay and ultrasonography in dairy cow. The results obtained from this studies were as follows. The results of reproductive examination in 85,983 cows were ovarian diseases 40,399 (47.0%), uterine diseases 11,912 (13.9%), pregnancy or pregnant failures 26,587 (30.9%), adhesion of reproductive tracts 172 (0.2%), freemartin 8 (0.01%), and others 6,905 (8.3%), respectively. The treatment status of reproductive dysfunction in 30,241 cows were silent heat or error of estrus detection 14,909 (49.3%), follicular cysts 3,750 (12.4%), luteal cysts 907 (3.0%), inactive ovaries 665 (2.2%), granulosa cell tumor of ovary 3 (0.01%) and endometritis 6,986 (23.1%), respectively. The indices of reproductive efficiency after the periodical examination of reproductive status were as follows; the mean intercalving inteual was reduced from 475 days at the first examination to 381 days at the last examination of reproductive status, the mean interval calving to conception was reduced from 186 to 98 days, the mean interval calving to first service was reduced from 106 to 66 days, the cows showing heat by 60 days postpartum were increased from 32 to 90%, the mean conception rate to first service was increased from 42 to 64%, and the mean service per conception was reduced from 2.6 to 1.8 times, respectively.