Ventricular performance, coronary flow, and MVo 2  in hamster cardiomyopathy with failure

Kumar, Amit; Plenge, Robert M.; Gamble, W. J.; Fj, Manasek; Monroe, RG

doi:10.1152/ajplegacy.1971.221.3.684

Cited by 2 publications

(1 citation statement)

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“…In more severe forms of heart disease, as in the cardiomyopathic Syrian hamster in congestive failure, oxygen consumption per gram of heart tissue was observed to double (Kumar et al, 1971). A similar finding was made in isolated papillary muscles from cats with right ventricular pressure overload hypertrophy and failure Cooper et al, 1973).…”

Section: Comparison With Other Studies On Energetics Of Hypertrophysupporting

confidence: 59%

Increased myothermal economy of isometric force generation in compensated cardiac hypertrophy induced by pulmonary artery constriction in the rabbit. A characterization of heat liberation in normal and hypertrophied right ventricular papillary muscles.

Alpert¹,

Mulieri²

1982

Circulation Research

246

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SUMMARY. Initial, recovery, and resting heat were measured in normal and hypertrophied papillary muscles in order to monitor the energetic consequences of the subcellular changes accompanying hypertrophy. The pulmonary artery was constricted in rabbits 4 weeks prior to measurements. Right ventricular papillary muscles were stimulated at 0.2 Hz and 21 °C in Krebs-Ringer solution under isometric conditions at optimum length. Peak twitch tension was 5.90 ± 0.25 g/mm 2 (SEM) in normal muscle (N) and 5.11 ± 0.47 g/mm 2 (NS) in pressure overload muscle (P). The maximal rate of tension generation decreased 26% (P < 0.02) from 15.9 ± 0.85 g/mm 2 sec (N) to 11.7 ± 1.37 g/mm 2 sec (P). Time-to-peak tension increased 30% (P < 0.001) from 627 ± 20 msec (N) to 816 ± 21 msec (P). The total activity related heat production per beat decreased 36% (P < 0.001) from 3.92 ± 0.26 mcal/g (N) to 2.51 ± 0.29 mcal/g (P). Initial heat was reduced 37% (P < 0.001) from 1.66 ± 0.10 mcal/g (N) to 1.04 ± 0.12 mcal/g (P). The isometric heat coefficient increased 43% (P < 0.005) from 8.76 ± 0.54 (N) to 12.5 ± 1 (P) showing increased economy in hypertrophy. There was an early fast phase (1.29 ± 0.12 mcal/g per sec) of initial heat lasting 396 ± 25 msec which was related to tension build-up. A slow phase (1.05 ± 0.07 mcal/g per sec) accompanied relaxation. In hypertrophy, the fast phase was 32% (P < 0.05) slower than normal and lasted 27% (P < 0.02) longer; the slow phase was 48% (P < 0.001) slower than normal. The ratio of recovery to initial heat (1.37 ± 0.09) was not different in N and P muscles. Resting heat was 2.08 ± 0.35 mcal/g per beat in N and 1.35 ± 0.23 mcal/g per beat in P muscles. Our present results and previous enzymatic and mechanical studies suggest that the relation between the compensated pressure overload hypertrophied and normal hearts is similar to the relation between slow and fast skeletal muscle. The changes in the heart that undergoes hypertrophy secondary to pressure overload are beneficial, since they meet the new hemodynamic demands with increased economy of force production. (Circ Res 50: 491-500, 1982)THIS investigation was undertaken to provide in vivo monitoring of subcellular changes induced by pressure overload hypertrophy in rabbit heart. The deposited film thermopile that we recently developed (Mulieri et al., 1977) is ideally suited to this study, since its low thermal capacitance, high time resolution, and sensitivity allow temperature changes accompanying an individual twitch to be correlated with the simultaneously recorded myogram. This offers the possibility of monitoring the time course of initial and recovery heat in an individual twitch response and correlating these with the intracellular mechanical and enzymatic processes known to accompany different portions of the twitch myogram.In addition, it is also of interest to compare myothermically derived values of total isometric energy liberation with values derived from oxygen consumption determinations, since the latter measurements are not in agreeme...

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Section: Comparison With Other Studies On Energetics Of Hypertrophysupporting

confidence: 59%

Increased myothermal economy of isometric force generation in compensated cardiac hypertrophy induced by pulmonary artery constriction in the rabbit. A characterization of heat liberation in normal and hypertrophied right ventricular papillary muscles.

Alpert¹,

Mulieri²

1982

Circulation Research

246

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show abstract

Ventricular performance, coronary flow, and myocardial oxygen consumption in rats with advanced thiamin deficiency

Phornphutkul¹,

Gamble²,

Monroe³

1974

The American Journal of Clinical Nutrition

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Ventricular performance, coronary flow, and MVo 2 in hamster cardiomyopathy with failure

Cited by 2 publications

References 0 publications

Increased myothermal economy of isometric force generation in compensated cardiac hypertrophy induced by pulmonary artery constriction in the rabbit. A characterization of heat liberation in normal and hypertrophied right ventricular papillary muscles.

Increased myothermal economy of isometric force generation in compensated cardiac hypertrophy induced by pulmonary artery constriction in the rabbit. A characterization of heat liberation in normal and hypertrophied right ventricular papillary muscles.

Ventricular performance, coronary flow, and myocardial oxygen consumption in rats with advanced thiamin deficiency

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