Possible Interaction: Acetylcholine and Phosphatidic Acid

“In these smooth muscle tissues, ACh (above 10 nM) reduced the amount of phosphatidylinositol 4,5-bisphosphate (PI-P2) and dose dependently increased the amount of phosphatidic acid.”

“…,ACh (10−5 M) either reduced or increased the … phosphatidyl inositol 4,5‐biphosphate (PI‐P2) or phosphatidic acid (PA) in the lipid fraction of the smooth muscle cells to 60% or to 350% … the control value, respectively, thereby indicating that ACh stimulates the phosphodiesteric hydrolysis of PI‐P2.”

“In cultured bovine chromaffin cells, acetylcholine as well as muscarine stimulated the 32Pi incorporation into phosphatidic acid , induced Ca2+ mobilization across the cells, and, in parallel, elevated intracellular cyclic GMP content.”

“In cultured bovine chromaffin cells, acetylcholine as well as muscarine stimulated the 32Pi incorporation into phosphatidic acid , induced Ca2+ mobilization across the cells, and, in parallel, elevated intracellular cyclic GMP content.”

“In the absence of Ca++, 50 micrometer ACh increased TPI breakdown and phosphatidic acid (PA) labeling by 16 and 38%, respectively.”

“ ACETYLCHOLINE stimulates the turnover of phosphatidylinositol (PI) and phosphatidic acid (PA) in brain in vitro and in vivo2,3.”

“The increase in the 32P labeling of PhA and PhI in the presence of norepinephrine or acetylcholine , which ranged from 2- to 6-fold, was found to be time- and concerntration-dependent.”

“At exogenous ACh concentrations of 10–5m and above, some ACh enters the synaptosomes by diffusion and significantly stimulates 32Pi incorporation into phosphatidic acid.”

“ Acetylcholine significantly increased the specific radioactivity of phosphatidic acid but had no effect on that of phosphatidylinositol or the nucleotide fraction.”

“Smaller increases in turnover on stimulation with ACh were seen in phosphatidylethanolamine and in phosphatidic acid.”