Effect of substrates on the mechanical performance of rhesus monkey papillary muscle

Summary This study examines the effect of different substrates on mechanical performance of excised papillary muscles from rhesus monkeys which had been divided into a control group and an experimental group fed a high fat diet for 5 months prior to sacrifice. The results show that performance is affected by available substrate for both groups. The performance of the experimental group was depressed relative to control with the short chain fatty acid, butyrate (C4), producing a monotonically decreasing force-frequency response. Relative to other mammals, isolated rhesus papillary muscles exhibited a protracted treppe which was sensitive to -adrenergic blockade with propranolol.Acknowledgments. I would like to thank Dr R.M. Larson, Dr R.L. McCann and Dr O.F. Hagan for making available the papillary muscles used in this study. Support for this work was provided in part by a grant from the Walker P. Inman Fund and grants from the NIH HL 17391 and HL 15448.