Amano Masafumi, Takahashi Akiyoshi, Yamanome Takeshi, Oka Yoshitaka, Amiya Noriko, Kawauchi Hiroshi, Yamamori Kunio
School of Fisheries Sciences, Kitasato University, Ofunato, Iwate, 022-0101, Japan.
Cell Tissue Res. 2005 Apr;320(1):127-34. doi: 10.1007/s00441-004-1058-4. Epub 2005 Feb 22.
Alpha-melanocyte-stimulating hormone (alpha-MSH) is a pituitary hormone derived by post-translational processing from proopiomelanocortin and is involved in background adaptation in teleost fish. It has also been reported to suppress food intake in mammals. Here, we examined the immunocytochemical localization of alpha-MSH in the brain and pituitary of a pleuronectiform fish, the barfin flounder (Verasper moseri), as a first step in unraveling the possible function of alpha-MSH in the brain. The ontogenic development of the alpha-MSH system was also studied. In the pituitary, alpha-MSH-immunoreactive (ir) cells were preferentially detected in the pars intermedia. In the brain, alpha-MSH-ir neuronal somata were located in the nucleus tuberis lateralis of the basal hypothalamus, and alpha-MSH-ir fibers were located mainly in the telencephalon, hypothalamus, and midbrain. Alpha-MSH-ir neuronal somata did not project their axons to the pituitary. The alpha-MSH-ir neurons differed from those immunoreactive to melanin-concentrating hormone. Alpha-MSH cells in the pituitary and alpha-MSH-ir neuronal somata in the brain were first detected 1 day and 5 days after hatching, respectively. The distribution of alpha-MSH-ir cells, neuronal somata, and fibers showed a pattern similar to that in adult fish 30 days after hatching. These results indicate that the functions of alpha-MSH in the brain and pituitary are different and that alpha-MSH plays physiological roles in the early development of the barfin flounder.
α-黑素细胞刺激素（α-MSH）是一种垂体激素，由阿黑皮素原经翻译后加工产生，参与硬骨鱼的背景适应。据报道，它在哺乳动物中也能抑制食物摄入。在此，我们研究了鲆鲽形鱼类条石鲷（Verasper moseri）大脑和垂体中α-MSH的免疫细胞化学定位，作为揭示α-MSH在大脑中可能功能的第一步。我们还研究了α-MSH系统的个体发育。在垂体中，α-MSH免疫反应性（ir）细胞优先在中间部被检测到。在大脑中，α-MSH-ir神经元胞体位于下丘脑基部的外侧结节核，α-MSH-ir纤维主要位于端脑、下丘脑和中脑。α-MSH-ir神经元胞体的轴突不投射到垂体。α-MSH-ir神经元与对促黑素细胞激素免疫反应的神经元不同。垂体中的α-MSH细胞和大脑中的α-MSH-ir神经元胞体分别在孵化后1天和5天首次被检测到。孵化后30天，α-MSH-ir细胞、神经元胞体和纤维的分布模式与成年鱼相似。这些结果表明，α-MSH在大脑和垂体中的功能不同，且α-MSH在条石鲷的早期发育中发挥生理作用。
