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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: .
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Does adenoviral SERCA1a gene transfer to adult rat ventricular myocytes induce physiological changes in calcium handling? Context: We examined the functional consequences of expressing adult rabbit fast skeletal sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA1a) in isolated adult rat ventricular myocytes. Myocytes were infected with a recombinant adenovirus harboring SERCA1a. Then 2 days after myocyte infection, protein expression was estimated using Western blot and SDS-PAGE analysis. We also measured the ATP-dependent oxalate-facilitated Ca(2+) uptake of myocyte homogenates and monitored Ca(2+) transient in myocytes loaded with the Ca(2+) dye, indo-1. SERCA1a gene expression resulted in a 36% increase in the total SERCA protein level in infected myocytes compared to controls (P<0.01), while SERCA2 and phospholamban levels did not change. This increase was associated with a 42% rise in SR Ca(2+) uptake (P<0.01), while tau (the time constant of Ca(2+) transient decay), and the time to peak fell by 32% (P<0.01) and 38% (P<0.001), respectively. Increasing the frequency of stimulation from 0.2 to 2 Hz decreased tau in both cell types (P<0.01). However, the decrease was much smaller in infected (P<0.01) than in uninfected cells (P<0.001). Isoproterenol (1 microM) further decreased tau in infected myocytes by 23% (P<0.05). In these cells, the diastolic [Ca(2+)](i) decreased by 50% (P<0.05) while the systolic [Ca(2+)](i) increased by 19% (P<0.05). No difference was found in the speed of SR Ca(2+) reloading after caffeine washout between the two cell types.
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Adenovirus-mediated SERCA1a gene transfer to adult rat ventricular myocytes enhances SR Ca(2+) handling to a degree similar to that observed following physiological stimulation. Final Decision: yes