February 1, 1990AJP Cell Physiology
Temperature dependence of myofilament Ca sensitivity of rat, guinea pig, and frog ventricular muscle
Key result
Cooling rat and guinea pig ventricular muscle from 29 to 1 degrees C reduced Ca sensitivity by 0.65 and 0.55 pCa units and reduced Cmax to 3.3% and 7.8% of baseline, respectively.
Population
Skinned ventricular muscle preparations from rat, guinea pig, and frog
Comparison
Cooling from 29°C (22°C for frog) to 8°C and 1°C vs Baseline temperature
Design
Preclinical
Authors
Discussion
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Member takes
Implication
May impair contractility during therapeutic hypothermia; leaves open whether myofilament effects occur in human myocardium.
Structured PICO
P
Population
Skinned ventricular muscle preparations from rat, guinea pig, and frog
I
Intervention
Cooling from 29°C (22°C for frog) to 8°C and 1°C
C
Comparator
Baseline temperature (29°C for rat and guinea pig, 22°C for frog)
O
Outcome
Myofilament Ca sensitivity (pCa vs. tension relationship) and maximum Ca-activated force (Cmax)surrogate
Cooling significantly reduces myofilament calcium sensitivity and maximum calcium-activated force across multiple species' ventricular muscle preparations.
Cite This Study
Harrison et al. (1990) studied this question. Cooling vs. 29 degrees C (22 degrees C for frog) was evaluated on Ca sensitivity and maximum Ca-activated force (Cmax). Cooling rat and guinea pig ventricular muscle from 29 to 1 degrees C reduced Ca sensitivity by 0.65 and 0.55 pCa units and reduced Cmax to 3.3% and 7.8% of baseline, respectively.