Thyrotropin-releasing hormone (TRH) stimulates alpha-melanocyte-stimulating hormone (alpha-MSH) secretion in amphibia as well as thyrotropin-stimulating hormone (TSH) and prolactin secretions in mammals. Since thyroid hormones regulate the stimulatory effect of TRH on TSH and prolactin, the possible role of thyroxine (T4) in the control of alpha-MSH secretion in amphibia, has been investigated. Neurointermediate lobes of Rana ridibunda were perifused in amphibian culture medium for 7 hr and the amounts of alpha-MSH released into the effluent perfusate were measured by radioimmunoassay. In vivo treatment with T4 (0.5 mg/kg twice a day for 9 days) did not modify the in vitro response of the neurointermediate lobes to TRH (10(-9) to 10(-7) M). In addition, prolonged infusion of T4 in vitro did not alter spontaneous and TRH-induced alpha-MSH release. In spite of the inhibitory effect of T4 on TRH-induced TSH and prolactin secretions in mammals, the present data show that, in frogs, thyroid hormone does not modulate the stimulation of alpha-MSH secretion induced by TSH.
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http://dx.doi.org/10.1016/0016-6480(83)90046-1 | DOI Listing |
Arch Dermatol Res
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Burn and Wound Repair Center, The Third Hospital of Hebei Medical University, No. 139, Ziqiang Road, Shijiazhuang, Hebei Province, 050035, China.
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Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
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January 2025
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address:
The melanocortin-3 receptor (MC3R) was recognized for its critical role in energy metabolism and inflammatory responses in mammals; however, its functions in fish remain poorly understood. This study characterized the mc3r gene in goldfish, investigating its sequence, tissue distribution, and pharmacological responses. The coding sequence of goldfish mc3r was 975 bp, translating to a 325-amino-acid protein typical of G protein-coupled receptors, with notable conservation across cyprinids.
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November 2024
Research Institute of Basic Sciences, Incheon National University, Incheon 22012, Republic of Korea.
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Department of Rehabilitation, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
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