Autonomous control of phosphatidylinositol turnover by histamine and acetylcholine receptors in the N1E-115 neuron-like cell line.
Histamine was found to stimulate the turnover of phosphatidylinositol (PI) in cultures of neuron-like NE-115 cells. Turnover was measured by increased production of [3H]inositol phosphates (breakdown) and by accelerated incorporation of 32P into PI (resynthesis). Data were consistent with hydrolysis of polyphosphoinositides being the initial event in receptor-stimulated PI turnover. This response to histamine desensitized within 10 min. Receptor systems for histamine and acetylcholine were tested for possible interactions: PI turnover in response to dual stimulation was approximately equal to the sum of the individual responses while prior desensitization of the acetylcholine receptor system had no effect on subsequent stimulation of the histamine receptor system. These results are consistent with the hypothesis that components of acetylcholine and histamine receptor systems responsible for PI turnover are autonomously organized and regulated. and regulated.