AJEBAK 55 (Pt. 4) 379-383 a977)
Brief Communication:
CHANGES IN ORNITHINE DECARBOXYLASE ACTIVITY AND CYCLIC ADENOSINE-3'-5'-MONOPHOSPHATE CONCENTRATIONS DURINC THE CELL CYCLE OF SYNCHRONIZED BHK CELLS by IIIROSHIGE HIBASAMI. MINOBU TANAKA. JUN NAGAI AND T A D A O I K E D A (From the Department of Biochemistry, Mie University School of Medicine, Tsu. Japan.)
(Accepted for piiblicatiun April 20, 1977.)
Summary. BIIK cells were synchronized by excess thymidine treatment which resuUed m approximately 903 synchrony. The activity of ornithine dccarboxylase (UiJC), the rate-limiting enzyme in poiyannne biosynthesis, elevated in earlv S phase, decreased in G, + M and C;, phase and then increased during late G ^ second round of early S phase. The' concei.tration of cyclic adenosinc-3'-5'monophosphate (cAMP) gradually decreased during S^G., + M phase and then .ncTeased dnring late G , ~ second round of early S pha'se. preceding that of . , ""'?.!*?;; . , ^^' "•^*^^'* *''^' ^^^ cellular cAMP level.
''^•*'^'''^>' ""'S^t I't' regiilated bv
INTRODUGTION. lQ79?n '''•%^^"'" ""Plicated in the regulation of growth process (Tal,or and Tabor l . ) / 2 . Dm->ng periods of rapid growth, polyamine levels have been observed to increase parallel with the mcreasc in RNA and protein s>nthesis (Ilerbst and Dion. 1970) The actn-i y of ODG has been olxservcd to increase rapidly in a variety of tissues in response to st.n.uh which untmte cell grouth (Morris and Fillingame. 1974; Hiba.sami et al 1976a and h) It has also been sho^^•n that the administration of niethylxanthine derivatives results in a rap.d mcreasc in cA\lP and subsequent increase in ODG activity in several tissues of the rat (Byus and Russel. 1974)^ Because both cAMP and pnlyannncs are associated with the regnlation "f cellular growth, and because of tl.e clth 2 ^fiC /ml of :iH-thyn,idine for 20 min. The labelled cell layers were washed twice with Hanks sahne. fixed with methanol for 5 min. dipped in autoradiographic emulsion, exposed for 2 weeks •uul stained with Giemsa solution. The percentage of mitotic eells was determined in celi preparations fixed with Garnoy solution for 30 min and stained with heniatoxyhn-eosin solution. The percentage of labelled cells ami mit
Brief Communication:
CHANGES IN ORNITHINE DECARBOXYLASE ACTIVITY AND CYCLIC ADENOSINE-3'-5'-MONOPHOSPHATE CONCENTRATIONS DURINC THE CELL CYCLE OF SYNCHRONIZED BHK CELLS by IIIROSHIGE HIBASAMI. MINOBU TANAKA. JUN NAGAI AND T A D A O I K E D A (From the Department of Biochemistry, Mie University School of Medicine, Tsu. Japan.)
(Accepted for piiblicatiun April 20, 1977.)
Summary. BIIK cells were synchronized by excess thymidine treatment which resuUed m approximately 903 synchrony. The activity of ornithine dccarboxylase (UiJC), the rate-limiting enzyme in poiyannne biosynthesis, elevated in earlv S phase, decreased in G, + M and C;, phase and then increased during late G ^ second round of early S phase. The' concei.tration of cyclic adenosinc-3'-5'monophosphate (cAMP) gradually decreased during S^G., + M phase and then .ncTeased dnring late G , ~ second round of early S pha'se. preceding that of . , ""'?.!*?;; . , ^^' "•^*^^'* *''^' ^^^ cellular cAMP level.
''^•*'^'''^>' ""'S^t I't' regiilated bv
INTRODUGTION. lQ79?n '''•%^^"'" ""Plicated in the regulation of growth process (Tal,or and Tabor l . ) / 2 . Dm->ng periods of rapid growth, polyamine levels have been observed to increase parallel with the mcreasc in RNA and protein s>nthesis (Ilerbst and Dion. 1970) The actn-i y of ODG has been olxservcd to increase rapidly in a variety of tissues in response to st.n.uh which untmte cell grouth (Morris and Fillingame. 1974; Hiba.sami et al 1976a and h) It has also been sho^^•n that the administration of niethylxanthine derivatives results in a rap.d mcreasc in cA\lP and subsequent increase in ODG activity in several tissues of the rat (Byus and Russel. 1974)^ Because both cAMP and pnlyannncs are associated with the regnlation "f cellular growth, and because of tl.e clth 2 ^fiC /ml of :iH-thyn,idine for 20 min. The labelled cell layers were washed twice with Hanks sahne. fixed with methanol for 5 min. dipped in autoradiographic emulsion, exposed for 2 weeks •uul stained with Giemsa solution. The percentage of mitotic eells was determined in celi preparations fixed with Garnoy solution for 30 min and stained with heniatoxyhn-eosin solution. The percentage of labelled cells ami mit
