Fig. 7. Age-related differences in the effect of volatile anesthetics on sarcoplasmic reticulum (SR) Ca²⁺release and reuptake. The SR was functionally isolated by inhibiting Ca²⁺influx (see Methods). To examine SR Ca²⁺release, reuptake was reversibly inhibited using cyclopiazonic acid (CPA), and cells were exposed to caffeine. The caffeine and CPA were washed, and the protocol was repeated in the presence of anesthetic. The increase time of the intracellular Ca²⁺concentration ([Ca²⁺]^I) response to caffeine (A ) represented the rate of SR Ca²⁺release and the amplitude (B ) SR Ca²⁺content. To examine reuptake, the SR was isolated but CPA was not added. The decrease time of the [Ca²⁺]ⁱresponse represented the rate of SR Ca²⁺reuptake. Overall, volatile anesthetic effects were more pronounced in adults, rather than in neonates. Brackets indicate significant differences. Values are mean ± SD.