COBALT BUT NOT HYPOXIA STIMULATES PDGF GENE-EXPRESSION IN RATS

Cobalt but not hypoxia stimulates PDGF gene expression in rats. Am. J. Physiol. 271 (Endocrinol. Metab. 34): E451-E457, 1996.-This study was done to investigate the influence of different forms of acute tissue hypoxia on the expression of platelet-derived growth factor (PDGF) A c hain (PDGF-A) and PDGF B chain (PDGF-B) genes in different rat organs. We found that acute normobaric hypoxia (8% O-2), carbon monoxide inha lation (0.1% CO), or lowering the hematocrit to 12% for 6 h had no eff ect on PDGF-A or PDGF-B gene expression in lung, heart, kidney, and li ver of Sprague-Dawley rats. Subcutaneous administration of cobaltous c hloride dose dependently increased PDGF-B mRNA by 125% in lungs, by 60 % in kidneys, but not in heart and liver. These findings suggest that acute tissue; hypoxygenation is not a significant stimulus for PDGF-A and PDGF-B gene expression in these major rat organs. Cobalt appears t o cause a tissue-specific increase of PDGF-B gene expression.