• Journal of Life Science
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• v.30 no.2
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• pp.202-210
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• 2020

As the elderly population increases, it is becoming important to prevent and treat muscle loss caused by aging or disease. Steroidal androgen in the protein assimilation steroid (AAS) system is mainly used to induce muscle improvement, but it is well known that long-term or excessive doses of AAS result in various side effects, although they are prescribed for various muscle and weight loss treatments. Research is therefore underway to explore natural substances that promote muscle renewal with relatively few side effects. However, despite many studies on the improvement of skeletal muscle and the reduction of muscle disease using natural products, there is still a lack of significant clinical results and mechanism studies. The promotion of muscle regeneration through treatment with natural substances typically involves three mechanisms: positive control of the muscle modulating factor (MRF), activation of the protein synthesis mechanism, and inhibition of the protein breakdown mechanism. A study of plant extracts that are known to have muscle neoplasmic stimulation effects, such as black ginseng, plum, and nutmeg, as well as single substances derived from natural products, such as creatine, catechin, and several fatty acids, is therefore described. We also summarize the mechanisms that have been identified so far through which each of these extracts or single materials facilitates muscle regeneration and the signaling pathways that they mediate.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.497-510
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• 1992

This study was attempted to comparative investigate the types and regional distribution of the endocrine cells in several vertebrates immunohistochemically using seven antisera. From carp pancreas could be observed 4 types which are insulin-, glucagon-, som- and BPP-immunoreactive cells. Insulin-immunoreactive cells were mainly distributed at the periphery and a few cells occupied the central region of the islets. Glucagon-immunoreactive cells were distributed at the periphery of the islets, and som - and BPP-immunoreactive cells were located at the central region. From frog pancreas could be observed 4 types which are insulin-, glucagon-, som- and BPP-immunoreactive cells. Insulin-immunoreactive cells were distributed throughout the islets. Som-immunoreactive cells were distributed at the periphery of the islets, and glucagon- and BPP-immunoreactive cells were found as single cell or as small groups located between the pancreatic acini. From snake pancreas could be observed 3 types which are insulin-, glucagon- and som -immunoreactive cells. Insulin-immunoreactive cells were distributed throughout the small islets, and they also were scattered at the periphery of the large islets. Glucagon-immunoreactive cells were distributed at the periphery of the islets, whereas som-immunoreactive cells were occupied the central region. From Ogolgae pancreas could be observed 4 types which are insulin-, glucagon-, som-and BPP-immunoreactive cells. Insulin-immunoreactive cells were distributed throughout the small islets, but at the periphery of the large one. Glucagon- immunoreactive cells were distributed at the periphery of the small islets and in the large islets showed scattering entired. Som-immunoreactive cells were distributed at the periphery of the small islets and in the large islets were located at the central region. A small numbers of BPP-immunoreactive cells were located at the periphery of the small islets and the exocrine regions. From the pancreas of the Korean native goat could be observed 6 types which are insulin-, glucagon-, som-, BPP-, 5-HT- and porcine-CG-immunoreactive cells. Insulin-immunoreactive cells were distributed throughout the islets. Som-immunoreactive cells were located at the periphery of the islets, but a tew were scattered at the central region of islets and in the epithelium of the secretory duct. Glucagon-, BPP-, 5-HT- and porcine CG-immunoreactive cells were distributed at the periphery of the islets. These findings indicated that the regional distribution patterns and cell types of pancreatic endocrine cells in vertebrates varies considerably among phylogenetically different vertebrates.

• Korean Journal of Animal Reproduction
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• v.4 no.1
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• pp.47-74
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• 1980

The present experiments were carried out to elucidate the effects of hypophysectomy and subsequent administration of sex hormone on thyroid, adrenal gland, gonads and blood plasma components in the rat. The jresults obtained were summarized as follows: The weight of the thyroid gland of both male and female hypophysectiomzed rats decreased markedly from 7 days up to 56 days after the hypophysectomy as compared to the control group. The administration of sex hormone (6 mg of testosterone propionate to male and 6 mg of hexestrol to female) to the hypophysectomized rat gave on effect on the change in the weight of the thyroid gland. The hopophysectomy decreased the uptake of radioactive iodine in the thyroid gland in both male and female rats with time. Subsequent administration of the sex hormone caused no effect. With regard to the histological changes of the thyroid gland, the hypophysectomy caused significant changes in the gland showing a remarkable degeneration. The function of the gland seemed to disa, pp.ar almost completely on 56th day after the hypophysectomy. Upon the administration of sex hormone after the hypophysectomy, however. the epithelia of the follicle which has changed to flat from has partly returned to its functional cubicfrom and nuclei recovered as nearly as normal. These recovery were more remarkable in the female than in the male. The hypophysectomy kept causing a significant decrease in the weight of the adrenal gland in male and female rats during the period of observation (up to 56 days) as in the case of thyroid gland. The administration of sex hormone has on effect in this respect either. The hypophysectomy also caused a marked morphological change in the gland: zona fasciculata and zona reticularis were dicreased in size quichly after the hypophysectomy. The administraton of the sex hormone to the hypophysectomized rat resulted in clear distinction among the three layers of the adrenal cortex which otherwise very diffused. In the male, this phenomenum was more remarkable than in the female and the pattern of the cell arrangements and the thickening of each layer became similar to those of normal rats. The gonads of both sexes have also kept decreasing in the weight and degenerated in morpohology after the hypophysectomy. However, the degenerate follicle became enlarged after the administration of hexestrol in the female. Furthermore, the vacuoles found in interstitial cells of hypophysectomized rat disa, pp.ared after the administration of testosterone in the male and the formation of spermatocytes seemed to be recovered. Hypophysectomy also caused a gradual increase in the contents of total protein, non-protein nitrogen, total lipid, cholesterol and calcium in the blood plasma with time. The concentrations of sodium, potassium and chloride in the blood did not change after the hypophysectomy. Sex hormone caused practically no change in above tendency.

• Korean Journal of Psychosomatic Medicine
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• v.15 no.1
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• pp.22-28
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• 2007

The pregnancy and postpartum period appear to be a time of heightened vulnerability for the development of major depression in some women. Postpartum depression affects 10% of women within a few weeks immediately postpartum. Postpartum depression is associated with disturbances in the mother-infant relationship, which in turn have an adverse impact on the course of child cognitive and emotional development. Depression during pregnancy is also common, although it has been relatively neglected. Psychopathological symptoms during pregnancy have physiological consequences for the fetus. Understanding the aetiology of perinatal depression requires integrating of multiple psychosocial and biological risk factors. The treatment of depressed pregnant women requires skilled decision making by psychiatrists. Risk-benefit analysis is appropriate method for intervention fur depression in pregnancy. Effective treatments for depression in pregnancy include psychotherapy, antidepressant medication and electroconvulsive therapy. In treatment of postpartum depression, the biological, psychological, and social interventions are included. Prescribing antidepressants(such as fluoxetine), estrogen in severe and chronic cases, and counselling can be effective for improving maternal mood and aspects of infant outcome. Ongoing research is directed to further elucidating neurohormonal and psychosocial contributions to depression during pregnancy or postpartum. Screening for risk factors and symptoms for depression need to be incorporated into antenatal and pediatric clinics.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.11-17
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• 2005

Egg masses of C. plumosus were collected from Jungnang Stream in Seoul and reared in an incubator chamber. The larvae of C. plumosus were treated with potential endocrine disruption chemicals (EDCs) such as Diethylhexyl phthalate (DEHP), Bisphenol A (BPA) and Tebufenozide, and the effects of morphological abnormalities were observed. The deformities of the mentum following exposure to EDCs showed the smooth/round tooth, the loss of ${\ge}$1 tooth, reduced median lateral teeth (MLT) and light brown color. The incidence rates of the mentum deformity were associated with chemicals: BPA (73.7 ${\sim}$ 90.9%)>tebufenozide (57.6 ${\sim}$ 78.9%)>DEHP (46.2 ${\sim}$ 85.7%). The deformity type of the mentum showed MIX (MLT+LT, 32 ${\sim}$ 46%)>MLT (25 ${\sim}$ 34%)>LT (lateral teeth, 3 ${\sim}$ 7%). Also, the incidence of MIX type was in the order of BPA (46%)>DEHP (33%) >tebufenozide (32%), and that of MLT type showed DEHP (34%)>tebufenozide (31%)>BPA (25%). As the concentration of Tebufenozide increased, the incidence of light brown mentum was dose dependent. While the incidences of light brown mentum following exposure to BPA and DEHP were not associated with their concentrations.

• Development and Reproduction
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• v.5 no.1
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• pp.1-8
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• 2001

Golden hamsters show the reproductive activity that is determined by the photoperiod (length of light per day). Photoperiod is an environmental factor that is predictable through an entire year. The hamsters are sexually active in summer during which day length exceeds night time. The critical length is at least 12.5 hours of light in a day where reproductive function is maintained. The information of photoperiod is mediated by the pineal gland because removal of pineal gland blocks the influence of photoperiod on reproductive activity. The hamsters without pineal gland maintain sexual activity and promote it in a situation that suppresses gonadal activity. The pineal gland secretes melatonin that reflects the photoperiod. The appropriate administrations of melatonin into both pineal intact and pinealectomized hamsters lead to a gonadal reression. The results suggest that melatonin constitutes a part of control mechanism whereby environmental information is transduced to neuroendocrine signal respensible for the functional integrity of the reproductive system. Despite of the intense studies, the action site of melatonin is on the whole unknown. It is mainly due to the lack of acute efffct of melatonin on the secretion of reproductive hormones. However, sexually regressed animals display the low levelsof gonadotropins and the augmentation of the hypothalamic gonadotropin-releasing hormone (GnRH) content, implying that the antigonadotropic effects either by photoperiod and/or by the treatment of melatonin are mediated by the GnRH neuronal system. The action mechanism by which melatonin exerts its effect on GnRH neuron needs to be investigated. Recent cloning of melatonin receptor will contribute to examine various and putative potencies of melatonin via its anatomical identification and the action mechanism of melatonin on target tissues at the molecular level.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.651-662
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• 2006

Phthalate esters that are used as plasticizers and also found at low levels in foods such as dairy products are often mentioned as suspected endocrine disrupters. The purpose of the present study is to elucidate whether perinatal exposure to di-n-butyl phthalate(DBP), diisononyl phthalate (DINP) and di-2-ethylhexyl adipate (DEHA) affects several aspects of reproductive function in rats especially sexual differentiation of the brain. To this end, the dams were provided with pulverized soy-free diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day (GD) 15 to postnatal day (PDN) 21, the day of weaning, and serum sex steroid hormone, gonadotropin levels and sexual behaviors after maturation were assessed. At Postnatal week (PNW) 20-21, serum levels of sex steroids and gonadotropins in both male and female rats, as well as estrous cyclicity in females, were not changed by perinatal exposure to DBP, DINP and DEHA, indicating that these chemicals did not affect sexual differentiation of the brain controlling the endocrine system of hypothalamo-pituitary-gonadal (HPG) axis. On the other hand, inhibitory influences on sexual behaviors, especially on ejaculation in males and lordosis in females, were observed by perinatal exposure to these chemicals. These results suggest that these chemicals may act directly on discrete regions of the hypothalamus regulating sexual behaviors, but not regulating gonadotropin secretion, thereby affect sexual differentiation of the brain with a resultant decrease in sex-specific behaviors in adulthood.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.285-292
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• 1999

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer known as one of endocrine disruptors. The present study was carried out to investigate the alterations of function and ultrastructure in rat testes after oral intubation of DEHP in dosages of 1g/kg/day, 2 g/kg/day or 3 g/kg/day in 0.5 ml of corn oil for 15 days. DEHP reduced the growth of body and testes, inhibited apermatogenesis and induced structural changes on various cell types of the rat testis. Leydig cells, Sertoli cells and the developing germ cells seemed to be impaired their differentiations in terms of the structural changes of cell organelles. The increase of heterochromatin in amount were common features in all 3 cell types. In addition, the Leydig cells were characterized by the swelling of smooth endoplasmic reticulum and perinuclear space, the increases in number and size of Iysosomes. The Sertoli cells became irregular in nuclear envelope and the number of Iysosomes and vacuoles seemed to be increased. There were some indications of necrosis of the germ cells, such as vacuolized nucleus and segregated nucleolus. And also, DEHP lowered the level of testosterone in experimental rat serum. DEHP suppressed apermatogenesis decreasing developing germ cells and these effects of DEHP on the rat testis were dose dependent. The detrimental effect of DEHP on apermatogenesis and ultrastructure of rat testes seems to be derived from the decreased level of testosterone by Leydig cells, followed by the abnomalities of Sertoli cells and the germ cells.

• Applied Microscopy
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• v.29 no.3
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• pp.353-362
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• 1999

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticize. known as one of endocrine disruptors. The present study was carried out to investigate the ultrastructural changes of prepubertal rat testis after oral administration of DEHP in dosages of 1 g/kg, 3 g/kg or 5g/kg in 0.5 ml of corn oil daily for a week. This study revealed the DEHP inhibited the development of seminiferous tubules and induced structural changes on various cell types of the rat testis. Leydig cells, Sertoli cells and the developing germ cells seemed to be impaired their differentiations in terms of the structural changes of cell organelles. The increase of heterochromatin in amount were common features in all 3 cell types. In addition, the Leydig cells were characterized by the increases in number and size of lysosomes and the scantiness of smooth endoplasmic reticulum. The Sertoli cells became irregular in nuclear envelope and the cytoplasm decreased, but the number of lysosomes and vacuoles seemed to be increased. There were some indications of necrosis of the germ cells, such as vacuolized nucleus and segregated nucleolus. These detrimental effects of DEHP on the rat testis were dose dependent and suppressed spermatogenesis decreasing developing germ cells in number and appearances. The effect of DEHP on ultrastructure of rat testis, as its known physiological functions, seems come from the decreased level of testosterone by Leydig cells, followed by the abnomalities of Sertoli cells and the germ cells.

• Journal of Life Science
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• v.16 no.6
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• pp.919-924
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• 2006

Toxicity evaluation systems for various chemicals and their metabolites have been developed during last decades. In this study, the acute toxicity of endocrine disrupting chemicals, such as endosulfan, bisphenol A, vinclozolin, and 3,5-dichloroaniline, was evaluated using HepG2 cell line, Lumbricus rubellus and Saccharomyces cerevisiae, respectively. The extents of toxicity of the chemicals in different bioassay systems varied substantially, such as endosulfan>3,5-dichloroaniline> bisphenol A in HepG2 cell line system, endosulfan>bisphenol A>3,5-dichloro aniline in L. rubellus system, and 3,5-dichloroaniline>endosulfan>bisphenol A in S. cerevisiae system. Meanwhile, no cytotoxicity was observed by treatment of vinclozolin in the evaluation systems. Our results suggest that earthworm and yeast are useful to evaluate acute toxicity of endocrine disrupting chemicals, and direct comparison of toxicity data from different bioassay systems is unattainable. Based on our results, we propose that the bioassay system with earthworm or yeast, a rapid, simple and economic system, could be applied as pre-test for the toxicity evaluation using human cell line or animals.