Effects of growth hormone and cortisol administration on plasma insulin-like growth factor binding proteins in juveniles of three subspecies of masu salmon (Oncorhynchus masou)
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
Authors: Yamaguchi, Ginnosuke; Habara, Shiori; Suzuki, Shotaro; Ugachi, Yuki; Kawai, Hisashi; Nakajima, Takuro; Shimizu, Munetaka
In this study, we examined the effects of porcine growth hormone (GH) and cortisol on plasma insulin-like growth factor binding proteins (IGFBPs) in juveniles of three subspecies of Oncorhynchus masou (masu, amago, and Biwa salmon). Ligand blotting using digoxigenin-labeled human IGF-I was used to detect and semiquantify three major circulating IGFBP bands at 41, 28, and 22 kDa, corresponding to IGFBP-2b, -1a, and -1b, respectively. GH increased plasma IGFBP-2b concentration in masu and Biwa salmon but suppressed it in amago salmon. Plasma IGFBP-2b levels were increased by cortisol in the three subspecies. Cortisol induced plasma IGFBP-1a in the three subspecies, whereas GH had a suppressive effect in masu and Biwa salmon. Sham and cortisol injections increased plasma IGFBP-1b levels after 1 day in masu and amago salmon, suggesting that IGFBP-1b is induced following exposure to stressors via cortisol. Increased IGFBP-lb levels were restored to basal levels when co-injected with GH in Biwa salmon, and the same trend was seen in masu and amago salmon. However, the suppressive effect of GH disappeared 2 days after injection in the three subspecies. Despite some differences among subspecies, the findings suggest that cortisol is a primary inducer of plasma IGFBP-1b; however, GH counteracts it in the short term. Therefore, GH has the potential to modulate the degree of increase in circulating IGFBP-1b levels during acute stress.
Long-lasting effects of postweaning sodium butyrate exposure on social behaviors in adult mice
BRAIN RESEARCH BULLETIN
Authors: Zhao, Penghui; Meng, Li; Dou, Mengxiao; Mao, Jiawen; Zhang, Ge; Zheng, Min; Yin, Xi; Tao, Zifei; Gong, Miao; Song, Li; Lian, Kaoqi; de-la-Paz, Omar Israel Velez; Guo, Qingjun; Shi, Haishui
Background: The function of gut microbiota as its role in normal physiology and involvement in brain function has gained a great deal of attention. The potential long-lasting effects of postweaning sodium butyrate (SB) exposure on social behaviors are still unknown; however it acts as one of the metabolites of gut microbiota. Methods: Male mice (24-day old) were exposed to SB through drinking water for 21 continuous days. A series of behavioral tests, mainly including bedding preference test (BP), sexual preference test (SP), social interaction test (SI), tube dominance test (SDT), forced swimming test (FST), open field test (OFT), novel object recognition task (NOR) were conducted at different time after 21-d SB exposure. Serum Trimethylamine oxide (TMAO) levels were investigated to gain insight into a potential mechanism. Results: Behavioral results indicated that postweaning SB exposure significantly decreased the social dominance status of low-ranked mice and decreased the sexual preference without affecting social interaction. SB exposure also exerted transient anxiolytic-like effects, while having induced a long-lasting depression-like effect without effects on memory formation. Postweaning SB exposure increased serum TMAO levels in mice, especially in lower-ranked mice, but decreased in higher-ranked mice. Limitations: Lack of understanding of the underlying mechanism. Conclusions: These findings provide direct evidence, for the first time, that postweaning SB exposure produces long-term effects on social behaviors in adult mice, mainly referring to sexual orientation, social dominance, and depression-like behaviors, which may be related to the serum TMAO levels, highlighting the long-lasting po-tential effects of gut-brain interaction on social behaviors.