Nutritional recovery with a soybean diet impaired the glucagon response but did not alter liver gluconeogenesis in the adult offspring of rats deprived of protein during pregnancy and lactation

Abstract

Nutritional recovery of early malnutrition with a soybean diet reduces liver glycogen stores in the fed state and produces liver insulin resistance. We investigated whether nutritional recovery on a soybean flour diet alters hepatic gluconeogenesis in the adult offspring of rats deprived of protein during pregnancy and lactation. Male rats from mothers that were fed either 17% (C) or 6% (L) protein during pregnancy and lactation were maintained on a 17% casein (CC, n = 16 and LC, n = 17), 17% soybean flour (CS, n = 10 and LS, n = 10), or 6% casein (LL, n = 10) diet after weaning. The soybean diet reduced basal serum glucose (soybean diet, 5.6 ± 0.6 mmol/L vs. casein diet, 6.2 ± 0.6 mmol/L; p < 0.05) but increased alanine aminotransferase mRNA/GAPDH (soybean diet, 0.062 ± 0.038 vs. casein diet, 0.024 ± 0.011; p < 0.01), phosphoenolpyruvate carboxykinase mRNA/GAPDH (soybean diet, 1.53 ± 0.52 vs. casein diet, 0.95 ± 0.43; p < 0.05), and glycerokinase protein content (soybean diet, 0.86 ± 0.08 vs. casein diet, 0.75 ± 0.11; p < 0.05). The serum glucose concentration (recovered groups, 5.6 ± 0.5 mmol/L vs. control groups, 6.2 ± 0.7 mmol/L; p < 0.05) and phosphoenolpyruvate carboxykinase activity (recovered groups, 2.8 ± 0.6 μU/mg vs. control groups, 3.6 ± 0.6 μU/mg; p < 0.05) were decreased in rats subjected to protein restriction in early life. The glucose area under the curve during the pyruvate tolerance test did not differ among groups, whereas glucose area under the curve after glucagon infusion was reduced by early malnutrition (recovered groups, 4210 ± 572 mg/dL·40 min vs. control groups, 4493 ± 688 mg/dL·40 min; p < 0.001) and by the soybean diet (soybean diet, 3995 ± 500 mg/dL·40 min vs. casein diet, 4686 ± 576 mg/dL·40 min; p < 0.05). Thus, the soybean diet impaired the response to glucagon but did not alter gluconeogenesis.