Abstract
Mammalian renal development differs from that of most of the other organs in that it proceeds through a series of three successive phases, each is marked by the formation of a more complex pair of kidneys. These kidneys are called the pronephros, mesonephros, and metanephros. The current study has been conducted to elucidate the developmental changes of rabbit kidneys during their pre- and postnatal life. In the present study we used samples, at different ages, of the rabbit kidneys from embryonic day 15 (E15) till maturity for light and scanning electron microscopical investigation. At E15, large mesonephros, occupied a great part of abdominal cavity of rabbit embryo, and undifferentiated metanephros were noticed. At E19 metanephros became differentiated into cortex and medulla with the initiation of nephron-forming stage. Additionally at this stage, the caudal series of mesonephros still detected but in degenerated and atrophied structure. Just before birth, at E30, the kidney demonstrated well-developed renal corpuscles, differentiated proximal and distal convoluted tubules, with apparently detectable loop of Henle and large collecting ducts. Shortly after birth rabbit kidney showed further morphogenesis and at two-months old, the kidney of rabbit with mature histological structure of the renal parenchyma was documented. In conclusion, the development of rabbit kidneys occurred mainly during the prenatal period while their histological maturity occurred from two to three weeks after birth. The present findings were discussed with previous publications.

Key words: rabbit, kidney, morphogenesis, mesonephros, metanephros