@article{WernerSchwedeGenieseretal.2011, author = {Werner, Katharina and Schwede, Frank and Genieser, Hans-Gottfried and Geiger, J{\"o}rg and Butt, Elke}, title = {Quantification of cAMP and cGMP analogs in intact cells: pitfalls in enzyme immunoassays for cyclic nucleotides}, series = {Naunyn-Schmiedeberg's Archives of Pharmacology}, volume = {384}, journal = {Naunyn-Schmiedeberg's Archives of Pharmacology}, number = {2}, doi = {10.1007/s00210-011-0662-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141828}, pages = {169-176}, year = {2011}, abstract = {Immunoassays are routinely used as research tools to measure intracellular cAMP and cGMP concentrations. Ideally, this application requires antibodies with high sensitivity and specificity. The present work evaluates the cross-reactivity of commercially available cyclic nucleotide analogs with two non-radioactive and one radioactive cAMP and cGMP immunoassay. Most of the tested cyclic nucleotide analogs showed low degree competition with the antibodies; however, with Rp-cAMPS, 8-Br-cGMP and 8-pCPT-cGMP, a strong cross-reactivity with the corresponding cAMP and cGMP, respectively, immunoassays was observed. The determined EIA-binding constants enabled the measurement of the intracellular cyclic nucleotide concentrations and revealed a time- and lipophilicity-dependent cell membrane permeability of the compounds in the range of 10-30\% of the extracellular applied concentration, thus allowing a more accurate prediction of the intracellular analog levels in a given experiment.}, language = {en} }