Dynamics of phospholipid metabolism in the sexual segment and kidney of the indian house lizard, Hemidactylus flaviviridis ruppell

Abstract

1. 1. The incorporation of radioactive inorganic orthophosphate into the sexual segment and kidney phospholipids was studied at various time intervals in sexually active and regressing lizards and following castration and testosterone administration. 2. 2. The incorporation of the label into the total phospholipids of the sexual segment as well as into the kidney is gradual and reaches a peak at 12 hr followed by a gradual decrease at later time intervals. 3. 3. Phosphatidic acid + polyglycerol phosphatide and phosphatidyl inositol+ phosphatidyl serine fractions incorporate the label rapidly during the first 30 min, while phosphatidyl choline and phosphatidyl ethanolamine fractions show heavy label at later intervals. The pattern of incorporation is similar in the phospholipids of the sexual segment and kidney, but the intensity of incorporation in the sexual segment is higher during the active season than in the regresssing season. 4. 4. Rapid early incorporation of the precursor into the phosphatidic acid fraction suggests its role in the biosynthesis of other complex lipids. The differential stimulation of the uptake of the label by sexual segment phospholipids is clear evidence of the selective action of testosterone on this target organ.