Effects of derivatives of cyclic amp and cyclic gmp on contraction force of cat papillary muscles.

Right ventricular kitten papillary muscles were incubated with dibutyryl adenosine 3',5'-monophosphate (dbcAMP) at varying concentrations as low as 1 X 10(-4)M. A positive inotropic effect was observed with all concentrations of dbcAMP. Concomitant administration of 5 X 10(-4)M monobutyryl guanosine 3',5'-monophosphate (mbcGMP) and 1-2 X 10(-4)M dbcAMP prevented the inotropic response observed when dbcAMP was used alone. When higher doses of dbcAMP were used (5 X 10(-4) M, 10 X 10(-4) M), there was no significant difference in the inotropic response seen between control tissues and papillary muscles pretreated with mbcGMP.