Objective To explore the effects and mechanism of autonomic nervous control on the proliferation of human hepatocytes. And to examine the cellular localization of some related receptors expression in human hepatocytes. MethodsNorepinephrine (NE), and its agonist, antagonist, acetylcholine (Ach), and its antagonist have been added to human hepatocyte line L02 and hepatoma cell line Bel7402. Modified MTT assay was employed to test the effects of them on the proliferation of the two cell lines at 4 h, 24 h, 48 h and 72 h. Immuocytochemical staining was used to examine the cellular localization of alpha1Badrenoceptor (α1BAR), β2AR and epidermal growth factor receptor (EGFR) expression in human hepatocyte line L02. ResultsNE potentiated the proliferation of human hepatocyte and hepatoma cell, which was enhanced significantly with dose increased. The proliferative rate of 4 h were higher than that of the other time points (P＜0.05). There were no significant differences between the group of NE combined with propanolol and the group of NE alone. Metaproterenol had no significant effect. Ach significantly inhibited the proliferation of human hepatocyte. Its effect was enhanced with dose increased. Atropine significantly attenuated the inhibitory effect of Ach at 24 h and 48 h (P＜0.05). Scoline alone inhibited hepatocyte proliferation at 24 h, 48 h and 72 h (P＜0.05, P＜0.01). In immunocytochemical staining, there were positive responses to α1BAR, β2AR and EGFR in all cultures. It was observed that the responses to α1BAR, β2AR and EGFR were mainly both cytoplasmic and cell membrane localized. Conclusion NE, the sympathetic neurotransmitter, acts via α1BAR potentiate the proliferation of human hepatocyte and hepatoma cell in the presence of serum. Ach, the vagus neurotransmitter acting via mAchR and nAchR inhibits hepatocyte proliferation.
Objective To prepare chitosan microcarriers and to use it to cultivate rat primary hepatocytes. Methods The crosslinked chitosan microcarrier was prepared by the reaction of glutaraldehyde with chitosan. Various factors that influence the preparation were studied and the reaction conditions were optimized. Rat primary hepatocytes cultured on chitosan microcarrier were observed by using phase contrast microscope and scanning electron microscope. Results Chitosan microcarriers with good properties could be prepared by adjusting the concentration of chitosan solution and the quantity of glutaraldehyde. Rat hepatocytes cultured on chitosan microcarriers retained the spherical shape as they have in vivo. And albumin secretion can last over one week. The highest albumin secretion rate reached 26.7μg/24h/ml. Conclusion Chitosan microcarriers is a promising scaffold for hepatocyte attachment, which can be used in bioartificial liver support system.