Cyclic nucleotides in hamster retina

The concentrations of cyclic 3':5'-adenosine monophosphate (cyclic AMP) and cyclic 3':5'-guanosine monophosphate (cyclic GMP) were determined in white light- and dim red light-adapted golden Syrian hamster retinas. Retinas from animals in dim red light had cyclic AMP concentrations of 9.29 +/- 2.94 pmol/mg of protein and cyclic GMP concentrations of 110.62 +/- 32.98 pmol/mg of protein. After white light adaptation, retinal cyclic AMP and cyclic GMP concentrations were reduced to 74% and 45% of the previous values, respectively. In another experiment with white light-adapted animals, the sex or method of immobilization of the animals (cervical dislocation vs sodium pentobarbital) had no significant effect on cyclic nucleotide values.