- Email: [email protected]
Changes in glyoxalase activities during differentiation of human leukaemia cells in vitro
244
2A5
EXPERIMENTAL STIMULATION OF LENS REGENERATION FROM THE VENTRAL PART OF NEWT IRIS. N.N. Grigorian, I.E. Malchevskaya and V.I. Mitashov. Institute of Developmental Biology, USSR Academy of Sciences, Moscow, USSR. On lO-th day after lens removal donor pigment cells of ventral part of the iris (IVP) were isolated, incubated with a mitogenic factor (synthetic Hydra morphogen) and implanted in the recipient lentectomized eye cavity, then cultivated during 50 days. The proliferative activity of IVP cells was studied using 3H-thymidine radioautography. As a result of preincubation with the Hydra morphogen, IVP cells retained the initially high level of proliferation (maximal at the moment of lens removal). Subsequent cultivation in the eye cavity maintained high proliferative activity for 10-15 days more, thus extending the total period of proliferation. Hence, the IVP cells pass through 6-7 mitotic cycles which appears to be enough for lens morphogenesis: lens formation occurs in 40% of cases. Our data explain the absence of lens regeneration from IVP in situ and support hypothesis of regulatory role of the number of transplanted cell divisions in transdifferentiation and regeneration.
CHANGES IN GLYOXALASE ACTIVITIES DURING DIFFERENTIATION OF HUMANLEUKAEMIACELLS IN VITRO. Hooper, M.J. Tisdale and P.J. Thornalley Pharmaceutical Sciences Institute, Aston University, Birmingham B4 7ET, U.K. When human promyelocytic leukaemia HL60 and erythroleukaemia K562 cells were incubated with N-methylformamide and a tetrazinone (CCRG 81045), substantial changes in the glyoxalase activities were induced. Treatment of HL60 cells with N-methylformamide and CCRG 81045 induces a dose-dependent decrease in glyoxalase I activity and a concomitant dose-dependent increase in glyoxalase I I activity, directly proportional to the number of functionally differentiated cells. With K562 cells, Nmethylformamide and CCRG 81045 induce an increase in both glyoxalase I and glyoxalase I I activities, although only CCRG 81045 induces functional differentiation. Despite the apparent disparity of the effect of differentiation on the glyoxalase activities in the two cell lines, in both cases the glyoxalase I / glyoxalase I I activity ratio decreases with the appearance of differentiated cells. This suggests that immature cells have an impaired capacity to metabolise S-Dlactoylglutathione.
.7.46
~7 THE EFFECT OF TIT~OX!I{E ON BIOG~TEA SIS OF INNER NiTOCH~{DRIAL ~ R A NES. DoKhamidov, T.Koval, N.Abljaeva, L.Murtazaeva. Institute of Biochemistry, Tashkent, USSR.
I~OSTCONJtDATION.Z.L PROGR--,[¢, 0~ THB NUCLEAR 2PPA~L~.Tb~G DIF2ERE}~IATION IN A CILIATE TETP~P~Yb~NA ~EPg~OPH.I. LA. A,Kaczano'~ski and I,Ggrnicka. Institute of Zoology,Warsaw University,",ars,.w ° 00-927/I ,Poland. Diploid cells of Tetrahymena thermo phila were qrossed to micronueleary defective A star to induce unilateral meiosis and unilateral transfer of g~metic nuclei.These nuclei diplo Idize after transfer by endoreduplication and become diploid nuclei with G-1,2c DNA content.Then DNA replication from 2c to 4c is transientlff arrested until separation of paIrs.If the endoreduplication is blocked with cycloheximlde,the exconjugants remain haploid. Competence for sndoreduplicstion is rJpnarently limited to some period of time after nuclear transfer.
Using the methods of differential spectrophotometry, polarography and electron microscopy is was shown, that physiological (0,03 mkg/g of wt.) and moderately high doses (0,7 ~tkg/g of wt.) of T a increased the biosynthesis of cyZochrome c+cl,b and a in embryos and newborns7 i~ iive~ up to 10-25%, in heart-up to 20-45%, with 1,5-2-fold increase of this biosynthesis in brain at early postnatal period. In parallel with this there was an increase in mito-chondrial respiration in all states and concentrations of cardiolipin. It was shown by the method of ele. ctron microscopy, that there was an increase in quantity of c~.,sts in hepatocyte and cardioms~ocyte mitochondria. Thus, the data obtained h a v e shown that T a stimulated the functional differentiation of mitochondria in ~he periods of growth and development. 88S
2A5
EXPERIMENTAL STIMULATION OF LENS REGENERATION FROM THE VENTRAL PART OF NEWT IRIS. N.N. Grigorian, I.E. Malchevskaya and V.I. Mitashov. Institute of Developmental Biology, USSR Academy of Sciences, Moscow, USSR. On lO-th day after lens removal donor pigment cells of ventral part of the iris (IVP) were isolated, incubated with a mitogenic factor (synthetic Hydra morphogen) and implanted in the recipient lentectomized eye cavity, then cultivated during 50 days. The proliferative activity of IVP cells was studied using 3H-thymidine radioautography. As a result of preincubation with the Hydra morphogen, IVP cells retained the initially high level of proliferation (maximal at the moment of lens removal). Subsequent cultivation in the eye cavity maintained high proliferative activity for 10-15 days more, thus extending the total period of proliferation. Hence, the IVP cells pass through 6-7 mitotic cycles which appears to be enough for lens morphogenesis: lens formation occurs in 40% of cases. Our data explain the absence of lens regeneration from IVP in situ and support hypothesis of regulatory role of the number of transplanted cell divisions in transdifferentiation and regeneration.
CHANGES IN GLYOXALASE ACTIVITIES DURING DIFFERENTIATION OF HUMANLEUKAEMIACELLS IN VITRO. Hooper, M.J. Tisdale and P.J. Thornalley Pharmaceutical Sciences Institute, Aston University, Birmingham B4 7ET, U.K. When human promyelocytic leukaemia HL60 and erythroleukaemia K562 cells were incubated with N-methylformamide and a tetrazinone (CCRG 81045), substantial changes in the glyoxalase activities were induced. Treatment of HL60 cells with N-methylformamide and CCRG 81045 induces a dose-dependent decrease in glyoxalase I activity and a concomitant dose-dependent increase in glyoxalase I I activity, directly proportional to the number of functionally differentiated cells. With K562 cells, Nmethylformamide and CCRG 81045 induce an increase in both glyoxalase I and glyoxalase I I activities, although only CCRG 81045 induces functional differentiation. Despite the apparent disparity of the effect of differentiation on the glyoxalase activities in the two cell lines, in both cases the glyoxalase I / glyoxalase I I activity ratio decreases with the appearance of differentiated cells. This suggests that immature cells have an impaired capacity to metabolise S-Dlactoylglutathione.
.7.46
~7 THE EFFECT OF TIT~OX!I{E ON BIOG~TEA SIS OF INNER NiTOCH~{DRIAL ~ R A NES. DoKhamidov, T.Koval, N.Abljaeva, L.Murtazaeva. Institute of Biochemistry, Tashkent, USSR.
I~OSTCONJtDATION.Z.L PROGR--,[¢, 0~ THB NUCLEAR 2PPA~L~.Tb~G DIF2ERE}~IATION IN A CILIATE TETP~P~Yb~NA ~EPg~OPH.I. LA. A,Kaczano'~ski and I,Ggrnicka. Institute of Zoology,Warsaw University,",ars,.w ° 00-927/I ,Poland. Diploid cells of Tetrahymena thermo phila were qrossed to micronueleary defective A star to induce unilateral meiosis and unilateral transfer of g~metic nuclei.These nuclei diplo Idize after transfer by endoreduplication and become diploid nuclei with G-1,2c DNA content.Then DNA replication from 2c to 4c is transientlff arrested until separation of paIrs.If the endoreduplication is blocked with cycloheximlde,the exconjugants remain haploid. Competence for sndoreduplicstion is rJpnarently limited to some period of time after nuclear transfer.
Using the methods of differential spectrophotometry, polarography and electron microscopy is was shown, that physiological (0,03 mkg/g of wt.) and moderately high doses (0,7 ~tkg/g of wt.) of T a increased the biosynthesis of cyZochrome c+cl,b and a in embryos and newborns7 i~ iive~ up to 10-25%, in heart-up to 20-45%, with 1,5-2-fold increase of this biosynthesis in brain at early postnatal period. In parallel with this there was an increase in mito-chondrial respiration in all states and concentrations of cardiolipin. It was shown by the method of ele. ctron microscopy, that there was an increase in quantity of c~.,sts in hepatocyte and cardioms~ocyte mitochondria. Thus, the data obtained h a v e shown that T a stimulated the functional differentiation of mitochondria in ~he periods of growth and development. 88S