The Action of Various Hormones and Metabolites upon Glucose Production by Isolated Hepatocytes from Lactating and Non-Lactating Ewes

Summary

Glucose production was measured from hepatocytes isolated from the livers of non-mated, 20- and 50-day lactating ewes (4 animals/group) in the presence and absence of various substrates and hormones. The output of glucose was reduced at peak lactation (20-day) compared to both the unmated (P < 0.05) and 50-day lactating groups (P < 0.05). There was no significant difference in glucose production between the unmated and 50-day lactating groups. In the presence of glucagon ( 1 uM), glucose production was stimulated above control levels (P < 0.05). However, insulin (1 uM) did not reduce glucose production compared to controls, while the effect of insulin and glucagon combined (1:1 uM) was not significantly higher than control values. Propionate, acetate and butyrate (10 mM) significantly increased glucose output above control values (P < 0.05), in all three groups of animals. Glucose output was relatively unchanged in the presence of alanine and glutamate (10 mM), while fructose supplementation (10 mM) resulted in a significantly reduced glucose output compared to the controls (P < 0.05).