Low taurine, gamma-aminobutyric acid and carnosine levels in plasma of diabetic pregnant rats: consequences for the offspring

Gestational diabetes compromises fetal development and induces a diabetogen ic effect in the offspring, including the development of gestational diabet es and the transmission of the effect to the next generation. Changes are not limited to glucose and insulin metabolism, and appear to be modulated by alterations at the hypothalamo-hypophyseal axis. In the prese nt work, serum concentrations are given for the non-protein aminoacids taur ine and gamma-aminobutyric acid (GABA), both neurotransmitters essential fo r normal brain development, and for the endogenous neuroprotector carnosine , a known anti-oxydans. Taurine levels are significantly below normal value s in mildly diabetic mothers, in their fetal and adult offspring, virgin an d pregnant, and in the fetuses of these pregnant offspring. GABA and carnos ine levels are at the limit of detection in the diabetic mothers and their offspring at every stage. It is concluded that the low taurine, GABA and ca rnosine levels in diabetic mothers and their fetuses might compromise the n ormal structural and functional development of the fetal brain. When adult, these offspring present a deficiency of the circulating levels of these ne urotransmitters involved in the hypothalamo-hypophyseal regulation of insul in secretion. This might contribute to the development of impaired glucose tolerance and gestational diabetes, thereby transmitting the effect to the next generation.