UNLABELLED: The mechanisms of uptake and intracellular distribution of 99mTc-tetrofosmin, 99mTc-MIBI and 201TI and the behaviors of 99mTc-tetrofosmin and 99mTc-MIBI in relation to Na+ were studied with primary cultures of myocardial cells. METHODS: Both the uptake and the washout of the tracers were sequentially measured. The cells were treated with ouabain, bumetanide, tetrodotoxin, dimethyl amiloride (DMA), nigericin and carbonyl cyanide m-chlorophenylhydrazone (CCCP) to observe the effects of the uptake and intracellular distribution of the traders. Cells equilibrated in buffers with or without Na+ were treated with monensin and DMA to evaluate the effect of Na+ on the accumulation of the tracers. RESULTS: Despite the similarities in uptake kinetics, there was a higher level of retention of 99mTc-tetrofosmin inside the cells. Ouabain, bumetanide and tetrodotoxin did not show any inhibitory effect on the uptake of 99mTc-tetrofosmin and 99mTc-MIBI, whereas they produced various degrees of inhibition of 201TI uptake. DMA produced approximately 35% inhibition of 99mTc-tetrofosmin uptake and 50% inhibition of 99mTc-MIBI uptake. Nigericin increased the uptake of 99mTc-MIBI by the cells. The addition of CCCP produced the release of 38% of the accumulated 99mTc-tetrofosmin and 52%-70% of the accumulated 99mTc-MIBI, indicating that these percentages of accumulation were related to mitochondrial uptake. Neither Na+-free buffer nor monensin had any significant effect on 99mTc-tetrofosmin accumulation, but they both caused increased accumulation of 99mTc-MIBI. CONCLUSION: The uptake of both 99mTc-tetrofosmin and 99mTc-MIBI through the cell membrane is partly related to the Na+/H+ antiporter system. Only part of the accumulated 99mTc-tetrofosmin inside the cells enters into mitochondria; most of the accumulated 99mc-MIBI is related to mitochondrial uptake. This uptake may be related to Na+.
UNLABELLED: The mechanisms of uptake and intracellular distribution of 99mTc-tetrofosmin, 99mTc-MIBI and 201TI and the behaviors of 99mTc-tetrofosmin and 99mTc-MIBI in relation to Na+ were studied with primary cultures of myocardial cells. METHODS: Both the uptake and the washout of the tracers were sequentially measured. The cells were treated with ouabain, bumetanide, tetrodotoxin, dimethyl amiloride (DMA), nigericin and carbonyl cyanide m-chlorophenylhydrazone (CCCP) to observe the effects of the uptake and intracellular distribution of the traders. Cells equilibrated in buffers with or without Na+ were treated with monensin and DMA to evaluate the effect of Na+ on the accumulation of the tracers. RESULTS: Despite the similarities in uptake kinetics, there was a higher level of retention of 99mTc-tetrofosmin inside the cells. Ouabain, bumetanide and tetrodotoxin did not show any inhibitory effect on the uptake of 99mTc-tetrofosmin and 99mTc-MIBI, whereas they produced various degrees of inhibition of 201TI uptake. DMA produced approximately 35% inhibition of 99mTc-tetrofosmin uptake and 50% inhibition of 99mTc-MIBI uptake. Nigericin increased the uptake of 99mTc-MIBI by the cells. The addition of CCCP produced the release of 38% of the accumulated 99mTc-tetrofosmin and 52%-70% of the accumulated 99mTc-MIBI, indicating that these percentages of accumulation were related to mitochondrial uptake. Neither Na+-free buffer nor monensin had any significant effect on 99mTc-tetrofosmin accumulation, but they both caused increased accumulation of 99mTc-MIBI. CONCLUSION: The uptake of both 99mTc-tetrofosmin and 99mTc-MIBI through the cell membrane is partly related to the Na+/H+ antiporter system. Only part of the accumulated 99mTc-tetrofosmin inside the cells enters into mitochondria; most of the accumulated 99mc-MIBI is related to mitochondrial uptake. This uptake may be related to Na+.
Authors: Min Young Lee; Sang Hun Lee; Jae Hong Park; Jung Sun Heo; Yu Jin Lee; Han Na Suh; Jung Jun Min; Young Soon Seo; Ho Jae Han Journal: J Vet Sci Date: 2007-09 Impact factor: 1.672
Authors: Alexis Broisat; Mirta Ruiz; Norman C Goodman; Stephen M Hanrahan; Bryan W Reutter; Kathleen M Brennan; Mustafa Janabi; Saul Schaefer; Denny D Watson; George A Beller; Henry F VanBrocklin; David K Glover Journal: Circ Cardiovasc Imaging Date: 2011-09-14 Impact factor: 7.792
Authors: Sergey M Korotkov; Vladimir P Nesterov; Irina V Brailovskaya; Viktor V Furaev; Artemy V Novozhilov Journal: J Bioenerg Biomembr Date: 2013-09-22 Impact factor: 2.945