Developmental Expression of Epidermal Growth Factor in Rat Kidney / 대한해부학회지

ABSTRACT

Epidermal growth factor (EGF) is well known to be one of regulating factor in proliferation. The aims of the present study were to elucidate the expression time and localization of expression of EGF in developing rat (Sprague-Dawley) kidney. Kidneys of 16-, 18- and 20-day-old fetuses, 1-, 3-. 7-, 14-, and 21-day-old pups and adult (3months) were preserved for light and electron microscopic immunocytochemistry. In adult rat kidney, EGF immunoreactivity was well localized in thick ascending limb and distal convoluted tubule. In developing rat kidney, EGF-positive cells appeared first in cortical thick ascending limbs and distal convoluted tubules of juxtamedullary nephrons at 3 days and 7 days after birth respectively, in cortical thick ascending limbs and distal convoluted tubules of cortical nephrons at 14 days after birth, and in medullary thick ascending at 21 days after birth. These findings suggest that renal EGF synthesized and secreted from distal tubule may possibly accelerate not proliferation but differentiation of the renal tubular epithelium at least in neonatal rat kidney.