Objective: To observe the effect of iodine deficiency and hypothyroidism on the expression of extracellular signal-regulated protein kinase 1/2 (ERK1/2) in the hippocampus of rat pups.
Methods: Pregnant Wistar rats (n=28) were randomly divided into control group, hypothyroid group (containing PTU 5 mg/L and 15 mg/L in drinking water) and iodine deficient group. The brains of 5 pups from each group were fixed by intracardiac perfusion at 7, 14, 21, 28 and 42 days after birth. Brain sections were observed and analyzed by immunohistochemistry on the expression of ERK1/2 in the CA1, CA3 and DG regions of hippocampus.
Results: The expressions of ERKl/2 in CA1 and CA3 regions of hippocampus in iodine-deficient group, PTU 5 mg/L group and PTU 15 mg/L group were significantly lower than those in control group (P < 0.05) at 14, 21, 28 and 42 days after birth. The expression of ERK1/2 in DG region was not significantly different in all four groups. The expressions of ERK1/2 were not significantly different in all four groups at 7 days after birth.
Conclusion: Iodine deficiency and hypothyroidism may decrease the expression of ERK1/2 in the hippocampus of pups.