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156 results on '"Hur, Sung-Pyo"'

6. Effects of dopamine and melatonin treatment on the expression of the genes associated with artificially induced sexual maturation in Japanese eel, Anguilla japonica.

Author

Byun, Jun‐Hwan, Hyeon, Ji‐Yeon, Hettiarachchi, Sachithra Amarin, Udagawa, Shingo, Mahardini, Angka, Kim, Jong‐Myoung, Hur, Sung‐Pyo, and Takemura, Akihiro

Subjects
ANGUILLA japonica, GONADOTROPIN releasing hormone, MELATONIN, CHORIONIC gonadotropins, MALE reproductive organs, MENSTRUAL cycle
Abstract

Japanese eel (Anguilla japonica) is a commercially important fish species in Asia. Understanding factors like photoperiod, temperature, and lunar cycles is crucial for successful aquaculture and managing its reproduction. Melatonin and dopamine (DA) are essential for regulating reproduction in vertebrates, including fish. This study investigated the effects of melatonin and DA on the reproductive system of mature male Japanese eels to better understand reproductive regulation in fish. To clarify the effects of these hormones on sexual maturation in eels, a critical stage in the reproductive process, sexual maturation was induced by injecting human chorionic gonadotropin, which stimulates the production of sex hormones. To check the effect of melatonin and DA on sexual maturation, DA, melatonin, and DA + domperidone were intraperitoneally injected into fish from each group (six per treatment) at a dose of 1 mg/kg body weight. The fish were then examined using quantitative RT‐PCR by comparing the messenger RNA level of reproduction‐related genes (gonadotropin releasing hormone 1; gnrh1, gonadotropin releasing hormone 2; gnrh2, follicle stimulating hormone; fshβ, luteinizing hormone; lhβ and DA receptor 2b; d2b), involved in the gonadotropic axis in eels, to those that received a control injection. The results indicate significant differences in the expression levels of gnrh1, gnrh2 and d2b in the brain and d2b, fshβ, lhβ in the pituitary at different stages of sexual maturation. Melatonin appears to enhance the production of sex gonadotropins, whereas DA inhibits them. These findings suggest an interaction between melatonin and DA in regulating reproduction in Japanese eels. Research Highlights: Melatonin enhances gonadotropin genes, while dopamine inhibits it in Japanese eels, revealing a dynamic interplay in their reproductive regulation [ABSTRACT FROM AUTHOR]

Published
2024
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15. Effect of light intensity and wavelength on diurnal activity of the banded coral shrimp Stenopus hispidus (Decapoda, Stenopodidae): a possible adaptation for a cleaner shrimp in reef environments

Author

Esaka, Yuriko, Yoshioka, Eiji, Takeuchi, Yuki, Hur, Sung-Pyo, and Takemura, Akihiro

Subjects
Diurnal cycles (Earth sciences) -- Observations, Coral reefs and islands -- Environmental aspects, Earth sciences, Science and technology
Abstract

Abstract: Most decapod crustaceans are nocturnal. However, because cleaner shrimp at cleaning stations act in concert with their hosts, they clean debris and parasites off the body surfaces of diurnal [...]

Published
2016
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18. DNA barcoding and morphological identification of spiny lobsters in South Korean waters: a new record of Panulirus longipes and Panulirus homarus homarus

Author

Hettiarachchi, Sachithra Amarin, primary, Hyeon, Ji-Yeon, additional, Mahardini, Angka, additional, Kim, Hyung-Suk, additional, Byun, Jun-Hwan, additional, Kim, Han-Jun, additional, Jeong, Jong-Gyun, additional, Yeo, Jung-Kyu, additional, Kim, Shin-Kwon, additional, Kim, Se-Jae, additional, Heo, Youn-Seong, additional, Sathyadith, Jonathan, additional, Kang, Do-Hyung, additional, and Hur, Sung-Pyo, additional

Published
2022
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36. Does depth become a permissive factor for reproductive habitat selection in the reef-associate damselfish Chrysiptera cyanea?

Author

Fukuoka, Tatsuki, Imamura, Satoshi, Yuki Takeuchi, Badruzzaman, Muhammad, Hur, Sung-Pyo, Bouchekioua, Selma, and Takemura, Akihiro

Abstract

The sapphire devil Chrysiptera cyanea (Quoy & Gaimard, 1825) is a reef-associated damselfish. Because this species exhibits repeated active reproduction in shallow seas during the spawning season, it is hypothesized that there is a preferred depth for successful reproduction. The aim of this study was to clarify whether the reproductive activity of the sapphire devil is influenced by habitat depth. In a field survey, many individuals could be seen in shallow areas (0-1.5 m), but few in deeper areas (> 3.1 m). Based on this observation, mesh cages containing one male and eight females were set at the surface (0 m; surface group) and the bottom (3 m; bottom group) of coral reefs during the spawning season and ovarian development in the two groups was compared. At the start of this experiment, all fish had a high gonadosomatic index (GSI) (6.33 ± 0.55) and ovaries with many vitellogenic oocytes at the tertiary yolk stage. Fish in the surface group maintained a high GSI (4.46 ± 0.83; 6.13 ± 0.91) and well-developed oocytes laden with yolk during the experimental period. Conversely, the GSI of the bottom group statistically decreased (1.73 ± 0.67; p = 0.0018) beginning three weeks after initiation of the experiment. In the bottom group, the number of vitellogenic oocytes in ovaries decreased gradually and, consequently, ovaries were occupied by immature oocytes at the perinucleolus stage. These results suggest that depth has an impact on ovarian development in the sapphire devil. Measurement of levels of dopamine (DA), its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC), and DA metabolic rate (DOPAC/DA) in the brain using high-performance liquid chromatography (HPLC) together with an electrochemical detection system indicated that DA levels increased (p = 0.046) and the metabolic rate of DA (DOPAC/DA) decreased (p = 0.0036) in the bottom group. These findings suggest that the combination of light wavelength and hydrostatic pressure impacts the regulation of reproduction in fish inhabiting shallow waters.

Published
2017
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39. Anti-inflammatory effect of supercritical extract and its constituents from Ishige okamurae

Author

Ko, Eun-Yi, Yoon, Weon-Jong, Lee, Hae-Won, Heo, Soo-Jin, Ko, Young-Hwan, Fernando, I.P. Shanura, Cho, Kichul, Lee, Chi-Heon, Hur, Sung-Pyo, Cho, Su-Hyeon, Ahn, Ginnae, Kim, Daekyung, and Kim, Kil-Nam

Subjects
0301 basic medicine, linoleic acid, NF-κB, 03 medical and health sciences, 030104 developmental biology, Ishige okamurae, Original Article, NF-kappaB, lipids (amino acids, peptides, and proteins), supercritical fluid extraction, NF- κB, anti-inflammatory
Abstract

The anti-inflammatory properties of the supercritical fluid extract of Ishige okamurae (SFEIO) on lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages. The lipid profile of the SFEIO, reviled the presence of palmitic acid (220.2 mg/g), linoleic acid (168.0 mg/g), and oleic acid (123.0 mg/g). SFEIO was found to exert it’s anti-inflammatory effects through inhibiting nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 production in LPS-stimulated RAW 264.7 cells, without inducing cytotoxicity. SFEIO did not effect on the LPS-induced p38 kinase phosphorylation, whereas it attenuated the extracellular-related signaling kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation. Furthermore, SFEIO inhibited the LPS-induced IκB-α degradation and p50 NF-κB activation. These results suggest that SFEIO exerts its anti-inflammatory effects in LPS-activated RAW 264.7 cells by down-regulating the activation of ERK, JNK, and NF-κB., EXCLI Journal;Vol. 15, 2016

Published
2016

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