• Journal of Embryo Transfer
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• v.20 no.1
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• pp.71-77
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• 2005

To investigate the influence of relaxin and insulin on the ovarian steroid secretion of porcine granulosa cells, we used porcine granulosa cells partially luteinized in a primary culture and examined the production of progesterone and $17{\beta}-estradiol$. Porcine granulosa cells were cultured in the presence of serum for 48 h after attachment and subsequently in the absence of serum fur 24 h. To confirm the dose dependency of relaxin or insulin, various concentrations (10, 100, 1000 ng/ml) of relaxin or insulin were added in the medium for the last 24 h, respectively. To investigate the combinational effect of relaxin and insulin, 100 ng/ml relaxin and/or 100 ng/ml insulin were added in the medium for the last 24 h in the presence or absence of luteinizing hormone (100 ng/ml). The medium was collected and used for radioimmunoassay to measure the production of progesterone and $17{\beta}-estradiol$. Relaxin or insulin increased the production of progesterone by dose dependency, respectively while they had no effect of the production of $17{\beta}-estradiol$. Relaxin (100 ng/ml) and/or insulin (100 ng/ml) significantly increased the production of progesterone in the presence of luteinizing hormone while they had no effect of the production of $17{\beta}-estradiol$. In conclusion, relaxin and/or insulin increased the progesterone secretion of porcine granulosa-lutein cells in vitro while had no effect on the production of $17{\beta}-estradiol$ and had no synergism on the effects. The effects of relaxin and/or insulin on the production of progesterone were augmented by the presence of luteinizing hormone.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.585-592
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• 2004

Our previous studies demonstrated that relaxin in concert with estrogen promotes development of the mammary parenchyma during the last third of gestation in gilts, and the specific relaxin-binding sites were present in the mammary gland. This study was conducted to determine if relaxin-binding sites in the mammary gland were functional relaxin receptors. Three cycling cross-bred gilts were bilaterally ovariectomized on day 0 of the experiment. Beginning on day 15 and continuing through day 29 post-surgery, the gilt received an im. injection of estradiol benzoate at 12-hr intervals. Beginning on day 22 post-surgery, highly purified porcine relaxin was administered(lug/hr) into the left fourth mammary gland from the anterior end via miniature osmotic pump. Physiological saline was administered to the right fourth mammary gland. The gilt was sacrificed on day 29 post-surgery and histological characteristics of the mammary parenchyma were examined. The mammary glands treated locally with saline showed little, if any, lobulo-alveolar development, whereas the mammary glands treated with relaxin showed not only marked lobulo-alveolar development but also prominent secretions in the alveoli. The saline-treated glands were characterized by relatively dense and highly organized collagen fiber bundles. Whereas, in the relaxin-treated mammary glands, collagen fiber bundles were dispersed and loosely organized. In conclusion, relaxin-binding sites in the mammary gland are functional relaxin receptors and relaxin acts directly on the pig mammary gland to promote development of the alveoli and remodeling of the extracellular matrix.

• Archives of Craniofacial Surgery
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• v.18 no.1
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• pp.9-15
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• 2017

Background: Relaxin is a transforming growth factor ${\beta}1$ antagonist. To determine the effects of relaxin on scar reduction, we investigated the scar remodeling process by injecting relaxin-expressing adenoviruses using a pig scar model. Methods: Scars with full thickness were generated on the backs of Yorkshire pigs. Scars were divided into two groups (relaxin [RLX] and Control). Adenoviruses were injected into the RLX (expressing relaxin) and Control (not expressing relaxin) groups. Changes in the surface areas, color index and pliability of scars were compared. Results: Fifty days after treatment, the surface areas of scars decreased, the color of scars was normalized, and the pliability of scars increased in RLX group. Conclusion: Relaxin-expressing adenoviruses improved the surface area, color, and pliability of scars. The mechanism of therapeutic effects on scar formation should be further investigated.

• Journal of Life Science
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• v.32 no.2
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• pp.175-188
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• 2022

Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IK_Ca channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI₂. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.64-64
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• 2004

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.519-525
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• 2010

Purpose: Of various effects of relaxin, we assumed that anti-fibrotic effects, neovascularization effects and vasodilatation effects of relaxin might enhance the survival rate of skin flap. In the current study, we used adenovirus expressing relaxin genes to examine whether these genes could enhance the survival rate of a skin flap. Methods: A total of 30 Sprangue-Dawley rats were divided into three groups: RLX group (10; relaxin virus injected group), CTR group (10; no gene coded virus injection group), and PBS group (10; PBS injected group). Each group was intradermally injected with the virus ($10^7$ PFU) and PBS 48 hours before and immediately before the flap elevation. A distally based flap $3{\times}9\;cm$ in size was elevated on the dorsal aspect of each rat. Following this, a flap was placed in the original location and then sutured using a #4-0 Nylon. A surviving area of the flap was measured and then compared on postoperative days 3, 7 and 10. Using a laser Doppler, the amount of blood flow was measured. On postoperative day 10, tissues were harvested for histologic examination and the number of blood vessels was counted. Results: There was a significant increase in the area of the flap survival in the RLX group on postoperative days 3 and 7. The Doppler measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. The number of blood vessels was significantly greater in the RLX group in the tissue harvested on postoperative day 10. The VEGF concentration was significantly higher in the RLX group than others in the tissues harvested on postoperative day 10. Conclusion: Following an analysis of the effects of relaxin-secreting adenovirus on the survival of a flap, the surviving area of the flap and the blood flow also increased. A histopathology also showed an increase in the number of blood vessels and the concentration of VEGF.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.14-15
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.14-15
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• 2005

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.79-79
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• 2005

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1412-1420
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• 2010

In this study, changes in testicular tissues of rats subjected to xylene and formaldehyde inhalation were evaluated. Three experimental groups were included in the study. Each group of rats was exposed to formaldehyde (6 ppm), technical xylene (300 ppm) or a combination of these two agents (150 ppm+3 ppm) for 8 weeks (8 h/d). Control groups were maintained for a period of eight weeks under the same conditions. Staining methods (triple staining, strep ABC method) were applied to examine histometric changes and relaxin like factor (RLF) expression in the testicular tissue. Immunostaining for RLF showed that density of staining for RLF decreased in rats exposed to formaldehyde. Formaldehyde or a combination of formaldehyde and xylene led to a decrease in seminiferous epithelial height. In conclusion, exposure of rats to formaldehyde and xylene-formaldehyde combinations adversely affects Leydig cells (RLF) and seminiferous epithelium of testicular tissue.