P Martin Petkovich

  • Citations Per Year
Learn More
To investigate possible mechanisms through which 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) affects cell proliferation and differentiation, we have studied the effects of 1,25-(OH)2D3 on the binding and mitogenic activity of epidermal growth factor (EGF) in RCJ 1.20 cells, an established, non-tumorigenic cell line derived from 21-day-old fetal rat calvaria.(More)
Since several aspects of the effects of vitamin A and 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on bone metabolism are quite similar, we examined the possibility that vitamin A effects on bone were mediated through the regulation of cytosolic 1,25-(OH)2D3 receptors. A clonal osteoblast-like cell line derived from rat osteosarcoma (ROS 17/2) was used as(More)
Based on the finding that retinoic acid (RA) increases 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] receptor number in ROS 17/2 cells, we investigated the effects of RA on the ability of 1,25-(OH)2D3 to regulate alkaline phosphatase activity and PTH-responsive adenylate cyclase in these cells. A maximally effective dose of 1,25-(OH)2D3 (10(-8) M) caused a 75-80%(More)
To analyze the phenotypic diversity of a clonal rat osteosarcoma cell line (ROS 17/2) we have subcloned the cell line and characterized four subclones, ROS 17/2-A.II, A.III, A.V, and A.XIV. The subclones retained many of the characteristics of the parent clone that are considered typical of normal osteoblast-like cells; they responded to parathyroid hormone(More)
The tissue distribution of retinoic acid (RA) throughout development is highly restricted, defined by the expression patterns of enzymes involved in RA synthesis and catabolism. Presented is a summary of recent research that examines the role of some of the enzymes involved in RA distribution, particularly those involved in RA catabolism (P450RAI). These(More)
The inducibility of 1 alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3] binding by all-trans-retinoic acid (RA) was examined in tumor-derived clonal bone cell lines, in established clonal cell lines derived from normal embryonic bone, and in cultured bone cell populations freshly isolated from 18- and 21-day fetal and 5-day-old neonatal rat calvaria. Levels of(More)
While it is well established that active vitamin D treatment increases dietary phytate phosphate utilization, the mechanism by which intestinal alkaline phosphatase (IAP) participates in phytate phosphate use is less clear. The ability of human IAP (hIAP) oral antibodies to prevent dietary phytate phosphate utilization in the presence of(More)
BACKGROUND/AIMS Vitamin D insufficiency and secondary hyperparathyroidism (SHPT) are associated with increased morbidity and mortality in chronic kidney disease (CKD) and are poorly addressed by current treatments. The present clinical studies evaluated extended-release (ER) calcifediol, a novel vitamin D prohormone repletion therapy designed to gradually(More)
Retinoic acid has previously been shown to alter 1-25-dihydroxyvitamin D3 [1,25-(OH)2D3] receptors in tumorigenic (ROS 17/2A, UMR 106M) and nontumorigenic (RCJ 1.20) bone-derived cells. The mechanism of this regulation is unclear. In the present series of experiments, we have investigated the mechanism of the retinoic acid-induced increase in 1,25-(OH)2D3(More)
Poly(methylmethacrylate) (PMMA) is a versatile polymer that displays desirable properties for development of cheap and disposable microfluidic devices for sensing biomolecular interactions. Atomic force microscopy (AFM) and chemical force titrations were used to determine the efficacy of surface modifications made to accommodate protein-substrate linkage.(More)
  • 1