Bone Abstracts

Caffeine is a methylxanthine found in many foods and is widely consumed by the human population. Therefore, its effects and mechanisms in various tissues have been widely studied. Various bone abnormalities have been observed in fetuses from rats treated with caffeine. But the genesis of these abnormalities is not known. The objective of this study was to verify the metabolism and activity of calvaria osteoblasts from offspring of rats treated with caffeine during pregnancy. The project was approved by animal ethics committee. 24 female Wistar rats were divided into four groups: one group without caffeine (control) and three groups with caffeine in following doses 25, 50 and 100 mg/kg daily throughout pregnancy. At birth, three puppies of each dam and group were euthanized for extracting osteoblasts from calvaria for in vitro tests. Osteoblasts from offspring of rats treated with caffeine had significantly increased activity, represented by increased conversion of MTT in formazan crystals, alkaline phosphatase activity, collagen synthesis, and mineralized nodules synthesis, as well as, significantly increased expression of gene transcripts for osteocalcin, osteopontin, sialoprotein, alkaline phosphatase and collagen I at all doses, but specially at 50 mg/kg. These results demonstrate that the in vivo effect of the caffeine in the osteoblasts is different when compared to studies that evaluated the effect of caffeine added directly to the cell culture medium. In conclusion, caffeine administered in vivo daily throughout pregnancy increases the metabolism and synthesis activity of calvaria osteoblasts from offspring of rats, which may be related to the occurrence of fetal abnormalities caused by caffeine.

Acknowledgment: FAPEMIG, CNPq and CAPES.