Maternal low‐zinc nutrition during lactation period affects the grown pups' sodium preference system in SD rats

It has been well known that maternal malnutrition during gestation or lactation period influences grown and matured pups□f dietary habit including in‐balanced dietary preference which causes metabolic syndrome in their later life. However, few data have been published yet even though in the rat, concerning about the effect of the shortage of zinc in maternal milk on grown rats' taste preference behavior or dietary habit. Therefore, we have done the maternal low‐zinc nutrition experiment, and low zinc (4.0 mg Zn/Kg) or zinc sufficient diet (33.7 mg Zn/Kg) was fed to the lactating mother during lactation period only, and zinc sufficient diet was fed to the all group□fs rats after weanling. The taste preference behavior study with water and 0.5M NaCl solution showed that maternal low‐zinc condition caused the increased NaCl preference in their matured pups up to 11 week‐old, even though their recovery from zinc deficiency after the weanling. We have found out a significant increase of norepinephrine (NE) secretion in the low zinc group in both the lateral‐ and paraventricular nucleus of hypothalamus after 15 to 45 minutes of oral 0.5M NaCl stimulation on the tongue by real‐time microdialysis‐HPLC system. Therefore, it is suggested that maternal low‐zinc nutrition during lactation period increased the matured pups' salt taste preference through the hypothalamus controlling system