Noguchi T, Kurata L M, Sugisaki T
Department of Physiology, Toho University School of Medicine, Tokyo, Japan.
Neuroendocrinology. 1987 Oct;46(4):277-82. doi: 10.1159/000124833.
Somatomedin C (SMC; insulin-like growth factor I) is thought to mediate the effects of growth hormone (GH) mainly on skeletal growth. SMC is produced in the liver but its production by various other fetal tissues including the brain, suggests a local regulatory role rather than a general one. A substance cross-reacting with recombinant human SMC (rSMC) was localized in the central nervous system (CNS) of the normal control and Snell dwarf mice by the unlabeled antibody peroxidase-antiperoxidase technique. rSMC-immunoreactive substance (rSMC-IRS) was found in the neuronal cells of forebrain structures. These included the caudate nucleus/putamen, hippocampus, thalamus, hypothalamus, globus pallidus and amygdala. No positive cells were found in the cerebral cortex. Investigation of the dwarf brain showed rSMC-IRS distributed in identical areas of the brain, although the intensity of the staining of rSMC-IRS was found to be weaker than that of the positive cells in the normal brain. Moreover, the number of positive cells was found to be less than in the normal brain. After treatment with bovine GH for 3 days the reduced number of positive cells and weaker staining in the cerebral sections of the dwarf mice did not change. Thus, rSMC may represent another peptide which is common to both the endocrine and the nervous system, with a potential neurotransmitter/neuromodulator function in the CNS.
生长调节素C（SMC；胰岛素样生长因子I）被认为主要介导生长激素（GH）对骨骼生长的作用。SMC在肝脏中产生，但其在包括大脑在内的各种其他胎儿组织中的产生表明其具有局部调节作用而非一般作用。通过未标记抗体过氧化物酶-抗过氧化物酶技术，在正常对照小鼠和斯内尔侏儒小鼠的中枢神经系统（CNS）中定位了一种与重组人SMC（rSMC）发生交叉反应的物质。在前脑结构的神经元细胞中发现了rSMC免疫反应性物质（rSMC-IRS）。这些结构包括尾状核/壳核、海马体、丘脑、下丘脑、苍白球和杏仁核。在大脑皮层中未发现阳性细胞。对侏儒小鼠大脑的研究表明，rSMC-IRS分布在大脑的相同区域，尽管发现rSMC-IRS的染色强度比正常大脑中的阳性细胞弱。此外，发现阳性细胞的数量比正常大脑中的少。用牛GH治疗3天后，侏儒小鼠脑切片中阳性细胞数量减少和染色减弱的情况没有改变。因此，rSMC可能代表另一种在内分泌系统和神经系统中都存在的肽，在中枢神经系统中具有潜在的神经递质/神经调节剂功能。
