Article révisé par les pairs
Résumé : When fetal rat long bones are incubated in the presence of 10(-8) M 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], steady-state parathyroid hormone-related peptide (PTHrP) mRNA levels are decreased. This decrease is temporary: it is observed as soon as after 3 h of exposure and reaches a nadir after 6 h. At that time, PTHrP mRNA levels are significantly lower in the experimental than in the control bones. However the inhibitory effect vanishes after 24 h, despite continuous exposure to 1,25(OH)2D3 for even 48 h. This is the first report showing that PTHrP mRNA expression can be regulated in rat fetal long bones in vitro by 1,25(OH)2D3.