ANTIBODY AGAINST SYNTHETIC RAT PTH PEPTIDE (1-34) BLOCKS PTH-MEDIATEDCAMP FORMATION AND PHOSPHATE-TRANSPORT IN OPOSSUM KIDNEY-CELLS

A novel antibody against synthetic rat parathyroid hormone (rPTH(1-34) ) was successfully produced in rabbits at a titer of 1:3,000, The abil ity of this antibody to block PTH was studied utilizing the hormone-se nsitive cAMP formation and Na+-dependent phosphate transport in the op ossum kidney (OK) cells, rPTH peptide(1-34) stimulated cAMP formation and inhibited Na+-dependent phosphate transport in OK cells in a dose- dependent manner. Treatment of OK cells with the antisera significantl y decreased the level of cAMP and attenuated the inhibition of Na+-dep endent phosphate transport in response to rPTH(1-34) at a dilution of 1:1,000. Nonimmune rabbit sera at the same dilution did not influence these hormone-sensitive effects. We conclude that antibody against syn thetic PTH peptide can be used to study the biological activities of t his hormone.