• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.159-164
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• 1993

The tissue levels of ornithine decarboxylase (ODC) during the estrous cycle and pregnancy were investigated in the pig. Sexually mature female cycling pigs were used. One animal was sacrificed on estrous cycle days 3, 10, 17, 18, 19, 20 and during pregnancy on day 11. 12, B. 14, 18, 19, 20, 48, 50 and 52. Tissues from the hypothalamus, pituitary, uterus, ovary and skeletal muscle were removed. They were homogenized in buffer, and supernatants were used for measurement of protein concentration and ODC activity. The release of $^14$CO$_2$ from radiolabeled ornithine was proportional to the amout of protein added over the range of 0.125~4mg and to the incubation time. ODC appered to have some relationship with the biological functions of the pituitary, ovary and uterus during the reproductive period, especially on day 19 of the estrous cycle, while it showed no such activities in hypothalamus and skeletal muscle of mature pigs. Uterine tissues had significantly more ODC activity than other tissues tested(p < 0.05).

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.251-256
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• 1999

The present study was conducted to evaluate whether vitrification could be used for ovarian tissue preservation. The important issue here is that the vitrification is very simple, easy, and economical compared to the conventional cryopreserving method that using automatic freezing instrument. Human ovarian cortical tissues were cryopreserved by vitrification with 5.5 M ethylene glycol and 1.0 M sucrose as cryoprotectant. Three points of temperature ($4^{\circ}C$, room temperature, and $37^{\circ}C$) and two points of duration (5 or 10 minutes) for cryoprotectant treatment were examined to determine the best condition for vitrification of the human ovarian cortical tissues. After thawing, viability of the isolated primordial follicles was examined by dye-exclusion method. Histological appearance of tissues before and after the cryopreservation was evaluated. There was no toxic effect of the 5.5 M ethylene glycol on the primordial follicles. However, when the tissues were treated with cryoprotectant at $37^{\circ}C$ for 10 minutes and exposed to liquid nitrogen, it seems likely that there is certain deleterious effects on the viability of the primordial follicles. The highest viability of the primordial follicles was obtained with the treatment of cryoprotectant at room temperature for 10 minutes. Follicles and oocytes survived after freezing and thawing had the similar normal shapes as was seen in the specimens before cryopreservation. It would be useful to apply vitrification in establishing ovarian tissue banking for clinical purposes.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.3
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• pp.229-235
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• 2021

Objective: In this study, the effects of Lactobacillus acidophilus on testosterone (TES), follicle-stimulating hormone (FSH), luteinizing hormone (LH), androgen-binding protein (ABP), factor-associated apoptosis (FAS), and total cholesterol (TC), as well as histopathological changes, were investigated in male rats fed a high-cholesterol diet. Methods: The study included three groups. The control (C) group was fed standard-diet for 8 weeks. The hypercholesterolemia (HC) group was fed a 2% cholesterol-diet for 8 weeks. The therapeutic group (HCL) was fed a 2% cholesterol-diet for 8 weeks and administered L. acidophilus for the last 4 weeks. FSH, TES, and FAS levels in testicular tissue were determined using an enzyme-linked immunosorbent assay (ELISA), while another sample was examined histopathologically. LH and ABP levels were determined using ELISA, and serum TC levels were assessed via an autoanalyzer. Results: In the HC group, the TC levels were significantly higher and the LH levels were lower (p<0.05) than in the C group. The ABP levels were lower (p>0.05). In the HCL group, the LH and ABP levels were higher (p>0.05) and the TC level significantly lower (p<0.05) than in the HC group. The TES and FSH levels were lower, and the FAS levels were higher, in the HC than in the C group (p<0.05). In the HCL group, levels of all three resembled control levels. Histologically, in the testicular tissue of the HC group, the cells in the tubular wall exhibited atrophy, vacuolization, and reduced wall structure integrity. However, in the HCL group, these deteriorations were largely reversed. Conclusion: Supplementary dietary administration of an L. acidophilus to hypercholesterolemic male rats positively impacted testicular tissue and male fertility hormone levels.

• Development and Reproduction
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• v.17 no.4
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• pp.469-475
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• 2013

In mammals, puberty is a process of acquiring reproductive competence, triggering by activation of hypothalamic kisspeptin (KiSS)-gonadotropin releasing hormone (GnRH) neuronal circuit. During peripubertal period, not only the external genitalia but the internal reproductive organs have to be matured in response to the hormonal signals from hypothalamic-pituitary-gonadal (H-P-G) axis. In the present study, we evaluated the maturation of male rat accessory sex organs during the peripubertal period using tissue weight measurement, histological analysis and RT-PCR assay. Male rats were sacrificed at 25, 30, 35, 40, 45, 50, and 70 postnatal days (PND). The rat accessory sex organs exhibited differential growth patterns compared to those of non-reproductive organs. The growth rate of the accessory sex organs were much higher than the those of non-reproductive organs. Also, the growth spurts occurred differentially even among the accessory sex organs; the order of prepubertal organ growth spurts is testis = epididymis > seminal vesicle = prostate. Histological study revealed that the presence of sperms in seminiferous tubules and epididymal ducts at day 50, indicating the puberty onset. The number of duct and the volume of duct in epididymis and prostate were inversely correlated during the experimental period. Our RT-PCR revealed that the levels of hypothalamic GnRH transcript were increased significantly on PND 40, suggesting the activation of hypothalamic GnRH pulse-generator before puberty onset. Studies on the peripubertal male accessory sex organs will provide useful references on the growth regulation mechanism which is differentially regulated during the period in androgen-sensitive organs. The detailed references will render easier development of endocrine disruption assay.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.184-191
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• 2000

Gametogenesis and the reproductive cycle of the marsh clam, Corbicula leana(Prime} were investigated monthly Hyongsan estuary, Korea from January to December 1998 by histological observation. C. leana had separate sexes, and oviparous. The gonads were located between the sub-region of mid-intestinal gland in visceral cavity and reticular cennective tissue. The ovary and testis were composed of a number of ovarian and testicular tubules, respectively, Mature oocytes were characterized by germinal vesicles with nucleoli and their sizes ranged $70\;to\;80{\mu}m$ in diameter. A number of mesenchymal tissues and pigment granular cells were distributed in the growing oocytes and spermatocytes during early developmental stages. With the further development of gonad, these tissuse and cells gradually disappeared. The monthly changes in the fatness index were closely related to reproductive cycle. Minimun size for sexual maturity was reached over 10.0 mm in shell length. The reproductive cycle could be classified into 6 stages : multiplicative (March to April): early growing and growing (May to June), mature (July to August), spent (September), degenerative (October) and recovery (November to February).

• Clinical and Experimental Reproductive Medicine
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• v.40 no.4
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• pp.155-162
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• 2013

Objective: Stress is known to be an inhibitor of the reproductive hypothalamic-pituitary-gonadal (HPG) axis. However, the neural and molecular connections between stress and reproduction are not yet understood. It is well established that in both humans and rodents, kisspeptin (encoded by the kiss1 gene) is a strong stimulator of the HPG axis. In the present study we hypothesized that endocannabinoids, an important neuromodulatory system in the brain, can act on the HPG axis at the level of kiss1 expression to inhibit reproductive function under stress. Methods: Adult male Wistar rats were unilaterally implanted with an intracerebroventricular cannula. Afterwards, the animals were exposed to immobilization stress, with or without the presence of the cannabinoid CB1 receptor antagonist AM251 (1 ${\mu}g/rat$). Blood samples were collected through a retro-orbital plexus puncture before and after stress. Five hours after the stress, brain tissue was collected for reverse transcriptase-quantitative polymerase chain reaction measurements of kiss1 mRNA. Results: Immobilization stress (1 hour) resulted in a decrease in the serum luteinizing hormone concentration. Additionally, kiss1 gene expression was decreased in key hypothalamic nuclei that regulate gonadotrophin secretion, the medial preoptic area (mPOA), and to some extent the arcuate nucleus (ARC). A single central administration of AM251 was effective in blocking these inhibitory responses. Conclusion: These findings suggest that endocannabinoids mediate, at least in part, immobilization stress-induced inhibition of the reproductive system. Our data suggest that the connection between immobilization stress and the HPG axis is kiss1 expression in the mPOA rather than the ARC.

• Korean Journal of Veterinary Pathology
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• v.1 no.2
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• pp.125-134
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• 1997

Porcine Reproductive and Respiratory Syndrome Virus infection (PRRSV) was confirmed by serology histopathology immunohistochemistry and bacteriologic examination in young pigs. Four suckling and six weaned piglets submitted from three different farms showed coughing sneezing labored rapid abdominal respiration lethargy and anorexia. Grossly apical and cardiac lung lobes appeared mottled with pale to dark tan discoloration. Submandibular and bronchial lymph nodes were tan and enlarged. All piglets were seropositive for PRRSV antibodies by the indirect immunofluorescent antibody(IFA) test. Microscopically lung lesions were characterized by hyperplasia and hypertrophy of type 2 pneumocytes infiltration of mononuclear cells in alveolar intersitium accumulation of necrotic debris in alveolar spaces accompanied by proliferation of alveolar multinucleated syncytial cells. Using immunohistochemical technique PRRSV antigens were demonstrated in alveolar macrophages and type 2 pneumocytes in histologic lung tissue sections. Also PRRSV antigens were detected in brain lymph nodes spleen and heart. Additionally piglets showed nonsuppurative meningoencephalitis mandibular necrotic lymphadenopathy splenic atrophy and myocardial necrosis.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.1
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• pp.40-49
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• 2019

Chronic and unpredictable stress can disrupt the female reproductive system by suppression for secretion of gonadotrophin-releasing hormone (GnRH) and gonadotrophin, resulted in ovarian malfunction and infertility. In the recent days, kisspeptin has been highly highlighted as a hypothalamic peptide which directly stimulates synthesis and release for GnRH. However, in spite of the key role of kisspeptin in the female reproductive system, little information is still available on the changes of its expression during ovarian cycle under stressed condition. Therefore, we induced chronic and unpredictable stress series to the female mice to analyze kisspeptin expression in the brain and ovary. Stressed mice exhibited changes of behavior and body weight gain during the stress assessment, which suggested that the present stress model in mice was successfully established. In the brain level, kisspeptin expression was attenuated than control. In the ovary level, the stressed mice displayed irregularly shrunk oocytes with broken zona pellucida throughout the follicle stages, pyknotic granulosa cells, decreased number of developing follicles and increased number of atretic follicles than the control. In case of kisspeptin expression in the whole ovary tissue, the expression level was decreased in the stressed mice. In detail, the less intensity of kisspeptin expression in the antral follicles phase was observed in the stressed mice than control mice, indicating that local function of kisspeptin during ovary cycle is highly associated with development of ovarian follicles. We expect that the present study has important implications for the fields of reproductive biology.

• BMB Reports
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• v.55 no.8
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• pp.370-379
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• 2022

Human pregnancy is a delicate and complex process where multiorgan interactions between two independent systems, the mother, and her fetus, maintain pregnancy. Intercellular interactions that can define homeostasis at the various cellular level between the two systems allow uninterrupted fetal growth and development until delivery. Interactions are needed for tissue remodeling during pregnancy at both fetal and maternal tissue layers. One of the mechanisms that help tissue remodeling is via cellular transitions where epithelial cells undergo a cyclic transition from epithelial to mesenchymal (EMT) and back from mesenchymal to epithelial (MET). Two major pregnancy-associated tissue systems that use EMT, and MET are the fetal membrane (amniochorion) amnion epithelial layer and cervical epithelial cells and will be reviewed here. EMT is often associated with localized inflammation, and it is a well-balanced process to facilitate tissue remodeling. Cyclic transition processes are important because a terminal state or the static state of EMT can cause accumulation of proinflammatory mesenchymal cells in the matrix regions of these tissues and increase localized inflammation that can cause tissue damage. Interactions that determine homeostasis are often controlled by both endocrine and paracrine mediators. Pregnancy maintenance hormone progesterone and its receptors are critical for maintaining the balance between EMT and MET. Increased intrauterine oxidative stress at term can force a static (terminal) EMT and increase inflammation that are physiologic processes that destabilize homeostasis that maintain pregnancy to promote labor and delivery of the fetus. However, conditions that can produce an untimely increase in EMT and inflammation can be pathologic. These tissue damages are often associated with adverse pregnancy complications such as preterm prelabor rupture of the membranes (pPROM) and spontaneous preterm birth (PTB). Therefore, an understanding of the biomolecular processes that maintain cyclic EMT-MET is critical to reducing the risk of pPROM and PTB. Extracellular vesicles (exosomes of 40-160 nm) that can carry various cargo are involved in cellular transitions as paracrine mediators. Exosomes can carry a variety of biomolecules as cargo. Studies specifically using exosomes from cells undergone EMT can carry a pro-inflammatory cargo and in a paracrine fashion can modify the neighboring tissue environment to cause enhancement of uterine inflammation.

• Reproductive and Developmental Biology
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• v.40 no.1
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• pp.7-13
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• 2016

Effectiveness of transgene transfer into genome is crucially concerned in mass production of the bio-pharmaceuticals using genetically modified transgenic animals as a bioreactor. Recently, the mammary gland has been considered as a potential bioreactor for the mass production of the bio-pharmaceuticals, which appears to be capable of appropriate post-translational modifications of recombinant proteins. The mammary gland tissue specific vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals. In this study, to minimize physiological disturbance caused by constitutive over-expression of the exogenous gene, we constructed new retrovirus vector system designed for mammary gland-specific expression of the hEPO gene. Using piggyBac vector system, we designed to express hEPO gene under the control of mammary gland tissue specific and lactogenic hormonal inducible goat ${\beta}$-casein or mouse Whey Acidic Protein (mWAP) promoter. Inducible expression of the hEPO gene was confirmed using RT-PCR and ELISA in the mouse mammary gland cells treated with lactogenic hormone. We expect the vector system may optimize production efficiency of transgenic animal and reduce the risk of global expression of transgene.