Maternal protein restriction during gestation and lactation: effects on brain,,

BONAVENTURA, M.M; CHAMSON, A; DURST, M.A; LUX-LANTOS, V.A.; ARANY, E.J

usa

Congreso; The Endocrine Society’s Annual Meeting; 2008

Endocrine Society

A balanced maternal diet with sufficient essential amino acids (AA) is major determinant of fetal growth. Previously we have shown that a low protein diet  (LPD) during critical periods of fetal and early life can have long-lasting deleterious effects on health in adulthood by altering glucose metabolism and  that Taurine supplementation to this LPD reversed the morphological changes seen in the pancreas suggesting that taurine will prevent  glucose imbalance in adulthood. Others have shown that the brain maintains its normal weight although other organs are not sparred. During embryonic development pancreatic islets cells share some common features with neurons, therefore our aim was to study the impact of Control (C: 20%) vs. a low protein diet (LPD: 8%) on amino acidic neurotransmitter contents such as Glutamate, Aspartate, Taurine and GABA in pancreas, brain and hypothalamus at birth (D1) and at 130 days of age (AD) rats determined by HPLC. In addition islet-insulin secretion under glucose stimulation (2mM, 12Mm and 20mM) was also studied in C, LP, and LP-taurine supplemented. (LP-T, 2.5% taurine in the drinking water) rats. Results showed that in the pancreas at D1 there was a significant decrease of taurine, glutamate and Aspartate in the LP group (p<0.01); this difference in neurotransmitter contents was not observed AD. Taurine decreased significantly with age in C (p<0.01); this was not observed in LPD animals.   GABA levels in pancreas were undetectable. In the brain and the hypothalamus taurine and glutamate significantly decreased from D1 to  AD without differences between treatments. Aspartate increased from D1 to AD without differences between C and LP. GABA was significantly lower in the brain at birth in the LP rats while hypothalamic GABA increased with age, with no differences between C and LPD. Glucose-stimulated Insulin secretion from islets isolated from 130 day-old animals indicated that insulin response to high glucose concentrations was significantly impaired in LP rats and the response was restored by taurine supplementation. These results suggest that while the nervous system seems to be protected from a LPD during gestation and lactation, maintaining amino acid neurotransmitter levels constant and impairing the pancreas from normal development and therefore reducing  glucose-stimulated insulin secretion  in isolated islets in adulthood although these effect were reversed by taurine supplementation. Thanks to the Support of Dairy Farmers of Canada