We describe a unique work-loop calorimeter with which we can measure, simultaneously, the rate of heat production and force-length work output of isolated cardiac trabeculae. The mechanics of the force-length work-loop contraction mimic those of the pressure-volume work-loops experienced by the heart. Within the measurement chamber of a flow-through microcalorimeter, a trabecula is electrically...

The membrane potential of the electrically quiescent circular muscle fibre is higher than that of the spontaneously active longitudinal muscle fibre. The length constant of circular muscle fibres is longer than that of the longitudinal muscle. The electrical activity of the longitudinal muscle membrane is enhanced by caffeine and PGE1 is suppressed for the circular muscle. Isotonic K Krebssolut...

The crude extract of Carthamus oxycantha (Co.Cr) was studied in vitro for its possible spasmogenic and spasmolytic activities. Segments of isolated rabbit jejunum 2-3 cm long were mounted in Tyrode’s solution and aerated with 95% oxygen in carbon dioxide. Isotonic responses were measured on Bioscience oscillograph. Isotonic responses were measured on Bioscience oscillograph. Co.Cr caused dose-d...

When the mode of contraction of the cat papillary muscle is changed abruptly from isotonic to isometric, the tension of the first isometric contraction is as much as 22% greater and lasts substantially longer than the subsequent stable isometric contractions attained after a few beats. This previously undescribed phenomenon is largely independent of preload or inotropic influences, but is great...

The objective was to study Dupuytren's myofibroblast cells in constrained collagen matrices in order to more closely emulate their in vivo environment and, to correlate their contractility with alpha-smooth muscle actin (alpha-SMA) expression and determine if dermal fibroblasts regulate Dupuytren's myofibroblast phenotype. Isotonic and isometric force contraction by cells isolated from Dupuytre...

abstract   extract prepared from aerial part of pycnocycla spinosa is a relaxant of rat ileum contractions. the objective of this research was to study the spasmolytic activity of p. spinosa root extract for comparison with the aerial part extract. hydroalcoholic extracts were prepared by percolation method. a portion of rat ileum was removed and suspended under 1 g tension in tyrode’s solution...