title: Cyclic nucleotide levels in mouse mammary epithelial cells during growth arrest and growth initiation in culture.
abstract: Intracellular levels of cyclic AMP (cAMP) and cyclic GMP (cGMP) were measured in high and low tumorigenic mouse mammary epithelial cells during growth arrest in 1% fetal bovine serum and during the first 60 minutes after serum stimulation of cell proliferation in arrested cultures. Stationary MCG-T14 cells, which are highly tumorigenic and grow to high densities in 1% serum, exhibited lower levels of cAMP, higher levels of cGMP, and a lower ratio of cAMP to cGMP than quiescent MCG-V14 cells, which have low tumorigenicity and achieve low cell densities in 1% serum. Within 5-10 minutes after cell growth was initiated in arrested cultures by the addition of serum, both cell lines responded with a fourfold to fivefold increase in cGMP and a concomitant 50% decrease in cAMP. MCG-T14 cells exhibited the highest intracellular levels of cGMP and the lowest cAMP to cGMP ratio within 10 minutes after serum addition.
mesh_terms: D000818:Animals; D002455:Cell Division; D002460:Cell Line; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism* / Q000473:pathology
chemical_list: D003470:Culture Media; D000242:Cyclic AMP; D006152:Cyclic GMP