Development of liver metabolism and serum hormones and metabolites in the perinatal pig.

In vitro glucose and pyruvate utilization by perinatal pig liver was determined at 90, 100, 110, and 114 days fetal age, and at 1 and 24 hours postpartum. The in vitro response of newborn pig liver to elevated glucose and insulin in vivo was also determined. Temporal patterns of increasing CO2 and total lipid and decreasing fatty acid production from glucose were associated with a decrease and subsequent increase in total liver DNA and protein at 110 days. A low capacity for gluconeogenesis from pyruvate was evident at 90 days fetal age, but doubled by 100 days then increased four-fold between 1 and 24 hours postpartum. In newborn pigs, the in vitro rate of glucose incorporation into CO2 and total lipids was increased by glucose feeding one hour before sacrifice, whereas fatty acid synthesis was increased by glucose feeding and/or intraperitoneal insulin injection. The in vivo glucose and/or insulin treatments also decreased serum growth hormone and cortisol levels. The results indicate that developmental changes in glucose utilization and synthesis by perinatal pig liver might be associated with changes in liver DNA content, whereas short-term changes at birth are related to serum concentrations of glucose and insulin.