Monday, May 12, 2008: Free Communications

Introduction and Aims:We attempted to develop the gene induction in parathyroid cell (PTC) using with the established method of direct injection into hypeplastic parathyroid gland (PTG).The induction of target genes in PTC was investigated in uremia-induced advanced secondary hyperparathyroidism (SHPT), whose expressions of vitamin D receptor (VDR) and Ca-sensing receptor (CaSR) in PTC were severely decreased.Methods: 5/6-nephrectomized Sprague-Dawley rats were fed a highphosphate diet for eight weeks.LacZ-inducted adenovirus (LacZ-Ad) was administered by direct injection into PTG (DI), intravenous from jugular vein and direct application on the PTG surface.The PTGs were excised 48 hours after the treatment and were evaluated by X-Gal staining.Moreover, one of the PTGs was treated by DI of VDR-or CaSR-inducted adenovirus (VDR-Ad and CaSR-Ad, respectively) and the other was treated by that of LacZ-Ad in the same rat.The immunohistochemical VDR and CaSR expressions of PTCs at the same timing were investigated.Results: Many X-gal-positive PTCs were observed in all over the PTG treated by DI of LacZ-Ad, however never in PTGs treated by the other administration of LacZ-Ad.Marked increases in the number of both VDRand CaSR-positive PTC were also confirmed in PTG treated by DI of VDR-Ad and CaSR-Ad, respectively.The significant differences compared with individual the other PTG treated by DI of LacZ-Ad in the same rat were noted.Conclusions: The induction of target gene in PTC of uremia-induced advanced SHPT model animal has been established.This technique may make it possible to investigate the various signaling pathways and changes of cell function and proliferation activity in PTCs inducted target genes.