The physiological functions of the ovary and development of the corpus luteum occur through the activation of endocrine hormones. In this process, estrogen, a reproductive hormone, is secreted in the ovarian follicle and corpus luteum and affects corpus luteum formation and regression. Estrogen controls the synthesis of reproductive hormones by binding to estrogen receptor–α and –β. Estradiol–17β, synthesized in the ovary, regulates the physiological function of the corpus luteum and the angiogenesis signaling pathway. Estrogen controls progesterone synthesis, which is regulated by StAR-transported cholesterol, P450scc-converted pregnenolone in mitochondria, and 3β-HSD-synthesized progesterone in the smooth endoplasmic reticulum. Estrogen secretion is also stimulated by kisspeptin and regulated by gonadotropin-releasing hormone, follicle-stimulating hormone, and luteinizing hormone. Moreover, the formation of the corpus luteum is closely regulated by angiogenesis. VEGF is an important factor in angiogenesis and plays a role in the survival, proliferation, and migration of endothelial cells. Especially, VEGF–A is a key factor in the physiological functions of endothelial cells. VEGF binds VEGFR–2 and affects the signaling pathways of PI3K, Akt, MAPK, and ERK. Also, VEGF binds to HIF–1α, inducing VEGF secretion. Estrogen promotes the activation of HIF–1α, while the activation of mTOR and Akt stimulates VEGF secretion. Therefore, estrogen is a major reproductive hormone in physiological function and the synthesis and secretion of endocrine hormones in the ovary and corpus luteum.

The aim of this study was to evaluate the changes of protein patterns in granulosa cells and corpus luteum in ovaries during the estrus cycle in cows. The estrus cycle was devided into five steps of follicular, ovulatory, early-luteal, mid-luteal and late-luteal phases. In results, 61 spots of total 85 spots were repeated on follicular phase and 51 spots of total 114 spots were repeated on ovulatory phase. The 40 spots of total 129 spots were repeated on early-luteal phase and 49 spots of total 104 spots were repeated on mid-luteal phase. Also 41 spots of total 60 spots were repeated on late-luteal phase. On the other hands, the 16 spots were indicated difference in follicular phase and ovulation phase had a difference 10 spots. It was showed difference No. 103 spot in ovulation phase, No. 135 spot in early-luteal phase and No. 175 and 176 spots in mid-luteal phase. Also, the 11 spots were expressed specifically in mid-luteal phase and No. 178 and 179 spots were difference of expression in late-luteal phase. We confirmed that there were 7 spots for ovulation, 4 spots for luteinization and 2 spots for luteolysis. Spot No. 89～93 in ovulation phase were transferrin, and spot No.94～98 were HSP60. Spot No. 103 was Dusty PK, spot No. 135 was OGDC- E2, and spot No. 175 and 176 were Rab GDI beta from luteinization. Spot No. 178 and 179 in luteolysis were vimentin. This results suggest that will be help to basic data about infertility.

본 연구는 도축된 한우의 황체난소, 낭종난소, 정상난소를 이용하여 체외 수정란 생산 시, 각각의 난소별 수정란 생산율을 분석하기 위하여 각 난소별 미성숙 난자의 회수율을 조사하였다. 15 18℃로 운반된 도축 유래 난소로부터 18G 주사침이 장착된 10 ml 주사 기를 이용하여 적색체 또는 황체가 형성된 난소, 직경 15 mm 이상의 낭종성 난소 및 4 10 mm의 정상난소로부터 미성숙 난자를 회수하여, 체외수정을 통한 분할율을 확인하 였다. 총 회수된 미성숙 난자와 이용 가능한 미성숙 난자의 수를 조사한 결과, 황체난소, 낭종난소 및 정상난소에서 총 회수된 미성숙 난자는 18.94±1.11, 18.57±1.42 및 20.24± 2.28개로 관찰되었으며, 그 중 성숙 배양에 이용된 미성숙 난자는 7.92±0.77, 8.22±1.31 및 10.70±1.02개로 확인되었고, 모두 유의적인 차이는 관찰되지 않았다(p<0.05). 또한, 난 소에서 총 회수된 미성숙 난자에 대한 성숙 배양으로의 효율은 황체난소, 낭종난소 및 정상난소에서 각 42.39±5.01, 43.60±5.15 및 53.55±3.19%로 조사되었으며 유의적인 차 이는 나타나지 않았다(p<0.05). 한편, 황체난소, 낭종난소 및 정상난소로부터 회수된 미성 숙 난자의 분할율은 77.46±1.60, 74.91±2.03 및 77.39±2.39%로 관찰되었고 유의적인 차 이는 나타나지 않았다(p<0.05). 본 연구의 실험 결과 황체 및 낭종난소와 정상난소에서 회수된 미성숙 난자의 개수 및 분할율에는 차이가 없다는 것을 알 수 있으며 이와 같은 결과를 통해 황체 및 낭종난소에서도 정상적인 난소에서와 마찬가지로 미성숙 난자가 채 란되며 이용가능하다는 것을 알 수 있었다. 하지만 보다 정확한 결과를 얻기 위해서는 추가적으로 성숙 및 발달율에 대한 조사가 이루어져 할 것이라고 생각된다.

This study was performed to the expressions of pregnancy-associated plasma protein-A (PAPP-A) and 20alpha-hydroxysteroid dehydrogenase (-HSD) in bovine corpus luteum during early pregnancy. To determine the function of PAPP-A gene during early pregnancy, we collected corpus luteum samples on 30, 60 and 90 days of pregnancy in bovine. The mRNA expression of PAPP-A, -HSD, progesterone-receptor (PR) and insulin-like growth factor binding protein4 (IGFBP4) gene was conducted by Real-time PCR. In parallel with mRNA levels, The protein expressions of PAPP-A and -HSD were detected by immunological analysis. The mRNA expressions -HSD and PAPP-A significantly increased on day 90 in the corpus luteum during pregnancy. The mRNA expression of PR and JGFBP4 in the corpus luteum progressively was enhanced at 30 to 60 day, but decreased on 90 day of pregnancy in the corpus luteum. The expression patterns of these genes, PAPP-A and -HSD were similar pattern in these tissues. In conclusion, PAPP-A and -HSD activity in corpus luteum could be played a role for early pregnancy manifestation.

The objective of this work was to determine the effect of corpus luteum (CL) grade on pregnancy rate after embryo transfer in Korean cattle and we found that CL development was linked to pregnancy rate. The in vivo derived blastocyst-stage embryos were transferred to 15 recipients synchronized in the estrus cycles. Based on size and palpable characteristics, CLs were categorized into three grade. The grade three CL is not to be identified by rectal palpation. The pregnancy rates tended to increase with the increase in CL size of recipients. In grade one, two, and three, the pregnancy rates were 62.5%, 50.0%, and 0%, respectively. This result suggests that pregnancy rates after embryo transfer might be affected by the CL status of recipients.

본 연구는 도축된 제주마의 난소를 이용하여 초음파 유도난포란 채취 기술을 확립하고자 난소, 난포 및 황체의 크기를 초음파상과 육안적 측정치를 비교하고자 하였다. 초음파상 측정치와 caliper를 이용한 실제 크기의 측정치 비교에서는 통계학적 차이는 보이지 않았다. 배란 직전의 난포를 조사한 결과, 초음파상에서 관찰한 것은 난소 한 개 당 평균 0.83개와 평균 크기는 2.86 m였으며, 육안으로 관찰된 것은 난소 한 개 당 평균 0.75개와 평균 크기는

Relaxin과 insulin이 돼지 난포 과립막세포의 스테로이드 호르몬 분비에 미치는 영향을 연구하기위하여 체외에서 황체화된 과립막세포에서 prosesterone과 의 생산을 조사하였다. 돼지난포 과립막세포를 혈청 존재하에 배양접시에 부착 후 48시간 동안 체외배양하고 무혈청 배지에서 24시간 배양하였다. Relaxin과 insulin의 용량의존성을 확인하기 위하여 다양한 농도 (10, 100, 1,000 ng/ml)를 각각 무혈청 배지에 첨가하였다.

본 연구는 과배란처리에 의한 수정란이식 시 우수한 수정란을 다량 확보하고 이식 후 수태율 향상을 위하여 수란우에 rbST처리가 수태율 및 progesterone 농도와 황체의 크기에 어떠한 영향을 미치는가를 조사하고자 실시하였다. 공란우는 Folltropin-V와 PGF₂α를 이용하여 과배란처리를 유도하여 12시간 간격으로 2 straw씩 3회 인공수정을 실시하였다. 공란우와 수란우는 대조구와 rbST 처리구로 구분하였으며, rbST (500 mg)처리는 발정발현 후 미근부에 근육 주사하였다. 과배란처리된 공란우의 수정란채란은 수정 후 7∼8일째에 비외과적인 방법으로 실시하였다. 수정란이식 후 수태율은 rbST 처리구에서 대조구보다 유의적으로 높았다 (64.0 vs. 47.1%; p<0.05). 채취한 혈액의 progesterone 농도 분석과 황체의 단면적를 조사한 결과 progesterone 농도는 대조구와 rbST 처리구에서 6일 동안 차이가 없었지만, 6일 이후부터 차이가 나타났으며 황체크기 역시 rbST 처리구에서 대조구에 비해 높게 나타났다. 본 연구결과에서 rbST처리는 이식 후 수태율의 향상시킬 수 있을 것으로 판단된다.

Prolactin (PRL) surge in cycling rats at proestrous afternoon has previously been reported as an inducer of apoptotic cell death of luteal cells. This death-inducing action of PRL seeins unusual, because PRL can he categorized as a cell-survival factor, if other known physiological functions of PRL are taken into account. In this study, the apoptotic action of PRL was assessed in cultured cells prepared from rat luteal tissue and underlying molecular /cellular mechanism of PRL-induced luteolysis was analyzed. The latest crop of corpora lutea (CLs) were enucleated from rat ovaries at 18:00 h on the proestrous day before the next ovulation. Donor rats were pretreated with CB154, a dopamine agonist, in order to he exempted from the endogenous PRL surge. The harvested GLs were dispersed and cultured with or without PRL (2g /ml) for 24 or 48 h. An addition of PRL to the culture medium changed the parameters indicative of cell death via apoptosis: a decrease in cell viability (MTT) and an increase in chromatin condensation. Most of the DNA breakdown in nuclei induced by PRL occurred in steroidogenic cells which were identified by 3-HSD activity staining, and the number of 3-HSD-positivecells were significantly decreased. Interestingly, most of the cells with an apoptotic nucleus adhered to one or more intact and seemingly non-steroidogenic cells. Because the expression of Fas has heen shown to be abundant in murine ovary, and Fas is known to have an exact physiological role in occurrence of apoptotic cell death, the membrane form-Fas ligand (rnFasL) was quantified in the cell lysate. An addition of PRL increased expression of mFasL. Moreover, an addition of concanavalin A (ConA), a T-cell specific activator, in place of PRL, enhanced the apoptotic parameters. Cumulatively, the apoptotic PRL action was addressed to cells unknown than steroidogenic lute~ cells. The most prohable candidate for the direct target cells is Tcells in the luteal tissue that can express mFasL in response to PRL.

This study was carried out to compare the actual size(length and height) of ovaries, follicles and corpora lutea of Korean native cow with those on sonograms. We used 3 different probes(3.5 MHz abdominal probe, 6.5 MHz transvaginal probe and 5.0 MHz transrectal probe) and a calipher for measurements of ovaries, follicles and corpora lutea on sonograms and actual size. Under water immersion, 157 ovaries were scanned with 3 probes and measured in actual size and compared each other. The average height and width of ovaries of Korean native cows were 17.403.99 and 34.236.02mm, respectively. In comparison of height, length of ovaries and preovulation follicles, we found that image with a transvaginal probe was nearly the same as the actual size(p<0.01), but with an abdominal probe the image was appeared larger than the actual size. In measurement(diameter) of preovulation follicles the transvaginal probe was proven to be more accurate to the actual size than other probes and in corpus luteum measurement all probes were accurate. In the comparison of number of follicles by different size ranges, there was no statistical difference in the count of follicles over 10 mm in diameter between the transvaginal probe and naked eyes.