A total of 10 male and 20 female Wistar rats (85–90 days) from the
colony of the State University of Londrina (UEL) were used as parental
generation. They were kept in a controlled environment with temperature
at 21 ± 2 °C; 12 h light/dark cycle (lights on at 6:00 a.m.) and had
free access to regular lab chow (Nuvital™, Paraná, Brazil) and tap water.
Rats were mated (2 females and 1 male per cage) and gestational day 0
was determined if there were sperm and estrus phase cells in vaginal
smears. On post-natal day (PND) 4, litters were culled to 8 pups keeping
4 males and 4 females wherever possible. Male pups were weaned on
PND 21 and divided into three groups (26 males/group).