McGaughey C, Jensen J L, Stowell E C
J Med. 1977;8(6):443-56.
Adenosine and guanosine cyclic monophosphates (cAMP and cGMP) exerted opposite effects at similar concentration and similar effects at markedly different concentrations on the yields of tumors promoted by vitamin A in hamster cheek pouch. Increasing the concentration of cAMP between 10(-5) M and 10(-3) M was associated with increases in tumor yield and diameter which partially or completely overcame the net tumor promotion inhibitory effects which were sometimes seen at 10(-5) M cAMP. In contrast, increasing the concentration of cGMP between 10(-5) M and 10(-3) M caused the net effects to change from increases to decreases in tumor yield without much change in diameter. The relative magnitudes of the tumor yield increasing and decreasing effects of the cyclic nucleotides varied substantially between experiments at constant concentration of cyclic nucleotide. Adenosine-5'-monophosphate (AMP) showed simultaneous tumor promotion inhibitory and growth stimulatory effects, the former effect being similar to that of cAMP but tumor yield decreased rather than increased as concentration of AMP was increased whereas the opposite occured with cAMP. Guanosine-5'-monophosphate (GMP) showed the tumor yield increasing effect of low concentraitons of cGMP but not the yield decreasing effect of high concentrations of cGMP. Adenosine (10(-3) M) showed a significant tumor yield increasing effect similar to that of 10(-3) M cAMP. Guanosine showed no significant effects at either 10(-3) M or 10(-5) M concentrations.
腺苷环磷酸和鸟苷环磷酸（cAMP和cGMP）在仓鼠颊囊内对维生素A促进的肿瘤生成量，在相似浓度时发挥相反作用，在显著不同浓度时发挥相似作用。将cAMP浓度在10⁻⁵M至10⁻³M之间升高，与肿瘤生成量及直径增加相关，这部分或完全克服了有时在10⁻⁵M cAMP时出现的肿瘤促进净抑制作用。相反，将cGMP浓度在10⁻⁵M至10⁻³M之间升高，导致肿瘤生成量的净效应从增加变为减少，而直径变化不大。在环核苷酸浓度恒定的实验中，环核苷酸对肿瘤生成量增加和减少的相对幅度差异很大。5'-单磷酸腺苷（AMP）同时显示出肿瘤促进抑制和生长刺激作用，前者作用与cAMP相似，但随着AMP浓度升高，肿瘤生成量减少而非增加，而cAMP则相反。5'-单磷酸鸟苷（GMP）显示出低浓度cGMP的肿瘤生成量增加效应，但未显示出高浓度cGMP的生成量减少效应。腺苷（10⁻³M）显示出与10⁻³M cAMP相似的显著肿瘤生成量增加效应。鸟苷在10⁻³M或10⁻⁵M浓度时均未显示出显著效应。
