Efeitos in vivo e in vitro da cafeína sobre o tecido cartilaginoso de ratos em crescimento

Abstract

The effect of caffeine on endochondral bone growth in rats (experiment 1) and on proliferation, apoptosis and differentiation of chondroblasts (experiment 2) was evaluated. In experiment 1, 38 female Wistar rats were distributed in the control groups and treated with caffeine (25, 50 and 100 mg / kg) during pregnancy and lactation. The plasma cortisol levels of mother and endochondral bone growth of offspring aging three and 21 days were evaluated. In experiment 2, cartilaginous epiphyses of femurs from newborn Wistar rats were cultured with and without caffeine for 0, 7, 14 and 21 days. The cartilages were subjected to morphometric analysis, immunohistochemical, Tunel technique and RT-PCR in real time. The means were compared by SNK. In experiment 1, it was concluded that caffeine inhibits endochondral bone growth; the effects of caffeine are more damaging in rats three days old, causing degeneration and death of chondroblast and that high doses of caffeine (100 mg / Kg) increase levels of plasma cortisol from mother rats, which is associated with more severe changes of the cartilage tissue of the offspring. It was concluded in experiment 2, that caffeine increases apoptosis in vitro, but at the same time, prevents the decrease of proliferative index and increased expression of cell differentiation gene transcripts represented by Sox-9, and by Runx-2.