IGF-1 production by primary cultured hepatocytes from rats and sheep

• Main Author: Luo, Qiu Jiang
• Published: University of Aberdeen 1992
• Subjects: 590; Hormones and the regulation of animal growth
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314610

Methods were established for the serum-free primary culture of rat and sheep hepatocytes. These were used to study the IGF-1 production by the cells. IGF-1 in media was separated by acid gel filtration or HPLC prior to RIA. IGF-1 production by both rat and sheep hepatocytes were time-dependent over 30 hours of culture. Production rates by rat cells in modified Eagle's medium, sheep cells modified Eagle's medium and Waymouth's medium were 13.1, 4.4 and 6.4 pmol/mg cell DNA/10 hours respectively. IGF-1 production by rat cells was very sensitive to altering concentrations of amino acids, glucose and both in the medium. IGF-1 production by sheep cells was also controlled by nutrients in modified Eagle's medium, but was not as sensitive as in rat cells. Growth hormone (GH), unlike insulin and T₃, had no effect on hepatic IGF-1 production in rat cells. In contrast, omitting GH from the medium for sheep cells decreased IGF-1 production by 20-60% in sheep cells. Insulin also controlled hepatic IGF-1 production in sheep. The results show the species difference in the hepatice IGF-1 production and control between rats and sheep. Data in this thesis are thought to provide the first published evidence of a direct nutritional control over IGF-1 production in rat hepatocytes and to give the first direct evidence that sheep hepatocytes produce IGF-1 and this is directly controlled by GH.