Accession Number : ADA266232


Title :   Post-Doctoral Research Award


Descriptive Note : Final rept. 1 Dec 1991-30 Nov 1992


Corporate Author : SOCIETY OF TOXICOLOGY WASHINGTON DC


Personal Author(s) : Cassedy, Joan W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266232.pdf


Report Date : 30 Nov 1992


Pagination or Media Count : 8


Abstract : Cortical collecting duct cells were cultured on permeable membranes and used to assess cellular transport properties for calcium/cadmium. Functional viability of the cells in culture were affirmed by their ability to absorb sodium and chloride, secrete protons and potassium, and respond appropriately to the hormones vassopressin and aldosterone. Calcium absorption by these cells was affected neither by sodium blockers or hormone inducers of cyclic AMP nor, surprisingly, by various calcium channel blockers. However, when the pH of the culture medium on the apical side of the cells was controlled artificially by buffer, calcium absorption was found to be affected. Decreasing the pH inhibited calcium uptake by cells, indicating that calcium and H+ transport were linked, possibly by a mechanism involving a H+/Ca++ exchanger. Cadmium had no apparent effect on calcium absorption until cadmium concentrations reached levels at which nonspecific, cytotoxic effects were observed. In another separate project, initial research efforts were undertaken to use electron paramagnetic resonance (EPR) to explain the mechanism by which endothelial/smooth muscle cells release the putative endothelium-derived relaxing factor (EDRF), nitric oxide (NO), from vasodilator drugs.


Descriptors :   *TRANSPORT PROPERTIES , *CYTOTOXINS , *CELLS(BIOLOGY) , CALCIUM , MEMBRANES(BIOLOGY) , SODIUM , CHLORIDES , CADMIUM , CHANNELS , BIOLOGICAL ABSORPTION


Subject Categories : Biochemistry
      Anatomy and Physiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE