Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

The sarcoplasmic reticulum Ca-ATPase of rabbit skeletal muscle can convert the energy derived from the Ca gradient into heat. This conversion varies depending on the temperature and on whether rabbit (endotherm)or trout (poikiloterm) sarcoplasmci reticulum versicles are used. The gradient doubled the yield of heat produced during ATP hydrolysis and the calorimetric enthalpy of ATP hydrolysis values found with both rabbit and trout varied between -10 and -12 kcal/mol in leaky vesicles (no gradient) and between -20 and -22 kcal/mol with intact vesicles (gradient). For the rabbit, the difference of enthalpy measured with and without gradient was detected in the range of 30 to 35 degree C and disappeared when the temperature was decreased below 30 degree. For the trout, the difference was detected between 20 and 25 degree C and disappeared below 20 degree. The effect of the gradient on the enthalpy for ATP hydrolysis was modified by dimethil sulfoxide, trifluoperazine and heparin.

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Presentation Number SAde meis0488
Keywords: heat, Ca-ATPase, SERCA