686 research outputs found
Inhibition by calcium of adenine nucleotide translocation in mitochondria isolated from ehrlich ascites tumour cells
Digitalitzat per Artypla
Kinetic evidence for calcium-ion and phosphate-ion transport systems in mitochondria from ehrlich ascites tumour cells
The chromosome make-up of mouse embryonic stem cells is predictive of somatic and germ cell chimerism.
Mouse pluripotent embryonic stem (ES) cells, once reintroduced into a mouse blastocyst, can contribute to the formation of all tissues, including the germline, of an organism referred to as a chimaeric. However, the reasons why this contribution often appears erratic are poorly understood. We have tested the notion that the chromosome make-up may be important in contributing both to somatic cell chimaerism and to germ line transmission. We found that the percentage of chimaerism of ES cell-embryo chimaeras, the absolute number of chimaeras and the ratio of chimaeras to total pups born all correlate closely with the percentage of euploid metaphases in the ES cell clones injected into the murine blastocyst. The majority of the ES cell clones that we tested, which were obtained from different gene targeting knockout experiments and harboured 50 to 100% euploid metaphases, did transmit to the germline; in contrast, none of the ES cell clones with more than 50% of chromosomally abnormal metaphases transmitted to the germline. Euploid ES cell clones cultured in vitro for more than 20 passages rapidly became severely aneuploid, and again this correlated closely with the percentage of chimaerism and with the number of ES cell-embryo chimaeras obtained per number of blastocysts injected. At the same time, the ability of these clones to contribute to the germline was lost when the proportion of euploid cells dropped below 50%. This study suggests that aneuploidy, rather than 'loss of totipotency', in ES cells, is the major cause of failure in obtaining contributions to all tissues of the adult chimaera, including the germline. Because euploidy is predictive of germline transmission, karyotype analysis is crucial and time/cost saving in any gene-targeting experiment
Inability of tributyltin-induced chloride/hydroxyl exchange to stimulate calcium transport in mitochondria isolated from flight muscle of the sheep blowfly Lucilia cuprina
Changes in the response of mitochondrial calcium transport to exogenous phosphate during development in flight muscle of the sheep blowfly Lucilla cuprina
Inhibition by local anaesthetics of adenine nucleotide translocation in rat liver mitochondria
The synergistic action (cross-talk) of glucagon and vasopressin induces early bile flow and plasma-membrane calcium fluxes in the perfused rat liver
Maturation in liver mitochondria of Ruthenium Red-sensitive calcium-ion-transport activity and the influence of glucagon administration in vivo and in utero
The influx of Ca2+ induced by the administration of glucagon and Ca2+-mobilizing agents to the perfused rat liver could involve at least two separate pathways
The subcellular location, maturation and response to increased plasma glucagon of Ruthenium Red-insensitive calcium-ion transport in rat liver
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