Solntseva T I, Belousova A K
Biull Eksp Biol Med. 1977 Oct;84(10):472-4.
Intracellular levels of cyclic AMP (cAMP), adenylate cyclase, and cAMP-phosphodiesterase activities at lag-period, exponential and stationary growth phases of hepatoma 22a were determined. It was shown that the transition of tumour cells from the lag-period to the exponential phase of growth was accompanied by the two-fold decrease of intracellular cAMP level on account of drastic activation of cAMP phosphodiesterase. Subsequently the cAMP level lowered more slowly until the cells entered the stationary phase of growth. In view of the fact that the adenylate cyclase activity failed to change at different growth phases of hepatoma 22a, it seems very proballe that the rise of cAMP phosphodiesterase activity could be a signal for the exit of tumour cells from the lag-period and their entrance into the mitotic cycle.
测定了肝癌22a细胞在迟缓期、指数生长期和平稳期的细胞内环磷酸腺苷（cAMP）水平、腺苷酸环化酶及cAMP磷酸二酯酶活性。结果表明，肿瘤细胞从迟缓期过渡到指数生长期时，由于cAMP磷酸二酯酶的剧烈激活，细胞内cAMP水平降低了两倍。随后，cAMP水平下降得较为缓慢，直到细胞进入生长平稳期。鉴于在肝癌22a的不同生长阶段腺苷酸环化酶活性未发生变化，cAMP磷酸二酯酶活性的升高很可能是肿瘤细胞从迟缓期进入有丝分裂周期的信号。
