An HPLC method was developed for the separation and quantitation of AMP, ADP, ATP and ZMP in liver tissue. The separation of a standard mixture of these four components is achieved within 30 minutes on a LC18-T chromatography column (25cm x 4.6, 5um with guard) and 100 mM potassium phosphate, ph 6.0 (buffer A) and a 9:1 ratio of buffer A with methanol (buffer B) used as the eluting solvent. Detection is carried out using a Waters 490 UV detector at 254 nm at 1.0 AUFS. All chromatograms are monitored and quanitated via an ESA Chromatography data station. The analysis of cAMP is accomplished through the homogination of 500 mg of insitu collected liver. The sample is centrifuged and the supernatant is neutralized. Separation is accomplished within 20 minutes on a LC18-T chromatography column (25cm x 4.6, 5um with guard) and mobile phase A: (90:10, 100mM potassium phosphate , pH 6.0/ methanol) and B:(80:20, 100mM potassium phosphate pH 6.0/methanol) measured at 254nm @.1AUFS.