Uptake of glucose analogs reflects the rate of contraction of cultured myocytes

The present study demonstrates that: a) adenosine and R-N⁶-(2-phenylisopropyl)-adenosine (R-PIA, A₁and A₃adenosine receptor agonist) inhibited [₃H]deoxyglucose uptake or [₃H]3-0-methyl-D-glucose uptake; b) sugar uptake reflects the rate of contraction in cardiac cultures; c) [₃H]deoxyglucose uptake or [³H]3-0-methyl-D-glucose uptake are useful quantitative probes for beating rate evaluation. A 25-40% decrease in [³H]deoxyglucose uptake (p<0.01) was obtained following 13-21 min treatment with 100 ?M adenosine together with 1 ?M dipyridamole or with 10 R-PIA, which inhibited spontaneous contractions. Adenosine (10 ?M) attenuated spontaneous beating rate and inhibited approximately 55% of the [³H]deoxyglucose uptake following 22 h treatment (p<0.01). 1 R-PIA also attenuated beating rate following either a short (1 min) or long (24 h) application and decreased [³H]deoxyglucose uptake by 2030% (p<0.01) during 0.5-24 h of treatment. A 157 9% and 205 11% increase (p<0.01) in [³H]deoxyglucose uptake was obtained at 27 and 37, respectively, compared with the uptake at 17C, which.