On the 21 first day of lactation the young of each group were aleatorily selected and following anesthesia, their heads severed; after histological treatment, serial 6 [micro]m sections on the frontal plane at the molar level, stained with hematoxilin and eosin, were obtained.
Ten albino female Wistar rats, weighing on an mean 200 g, and 80 aleatorily chosen young from various litters, were kept in individual cages, receiving solid food and water ad libitum, and were aleatorily divided in two groups: