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We studied glucose metabolic adaptations in the intrauterine growth-restricted (IUGR) rat offspring to decipher glucose homeostasis in metabolic programming. Glucose futile cycling (GFC), which is altered when there is imbalance between glucose production and utilization, was studied during a glucose tolerance test (GTT) in 2-day-old (n = 8), 2-mo-old (n = 22), and 15-mo-old (n = 22) female rat offspring. The IUGR rats exposed to either prenatal (CM/SP, n = 5 per age), postnatal (SM/CP, n = 6), or pre- and postnatal (SM/SP, n = 6) nutrient restriction were compared with age-matched controls (CM/CP, n = 5). At 2 days, IUGR pups (SP) were smaller and glucose intolerant and had increased hepatic glucose production and increased glucose disposal (P < 0.01) compared with controls (CP). At 2 mo, the GTT, glucose clearance, and GFC did not change. However, a decline in hepatic glucose-6-phosphatase (P < 0.05) and fructose- 1,6-biphosphatase (P < 0.05) enzyme activities in the IUGR offspring was detected. At 15 mo, prenatal nutrient restriction (CM/SP) resulted in greater weight gain (P < 0.01) and hyperinsulinemia (P < 0.001) compared with postnatal nutrient restriction (SM/CP). A decline in GFC in the face of a normal GTT occurred in both the prenatal (CM/SP, P < 0.01) and postnatal calorie (SM/CP, P < 0.03) and growth-restricted offspring. The IUGR offspring with pre- and post-natal nutrient restriction (SM/SP) were smaller, hypoinsulinemic (P < 0.03), and hypoleptinemic (P < 0.03), with no change in GTT, hepatic glucose production, GFC, or glucose clearance. We conclude that there is pre- and postnatal programming that affects the postnatal compensatory adaptation of GFC and disposal initiated by changes in circulating insulin concentrations, thereby determining hepatic insulin sensitivity in a phenotype-specific manner. [ABSTRACT FROM AUTHOR]

Part II. Reports on the contribution of chain elongation and desaturation relative to fatty acid synthesis to the accumulation of plasma and tissue triglycerides. Determination of the distribution of certain fatty acids of triglycerides in several tissues of Zucker diabetic fatty (ZDF) rats and their lean littermates; Examination of lipogenesis using deuterated water method; Percentages of fatty acid conversion and lipogenesis suppression.

Features a study which investigated the role of leptin in the regulation of lipogenesis by examining the effect of dietary micronutrient composition of lipogenesis in the leptin receptor-defective Zucker diabetic fatty rat (ZDF) and its lean litter mate (ZL). Mechanism of action of leptin; Methodology and results; Analysis of results.

Presents information on a study which examined two methods of measuring rates of gluconeogenesis based on label redistribution after the introduction of [U-...C]glucose. Discussion on the approaches and assumptions; Information on [U-...C]glucose.

Cites a study, which provides a method to find an estimation of gluconeogenesis. Chemical compound used to find out the estimation; Effect of isotope equilibrium on hepatic glucose output and fractional gluconeogenesis; Effect of lactate infusion on gluconeogenesis.