EXPERIMENTAL MYOCARDIAL ISCHEMIC-INJURY .1. COMPARISON OF STADIE-RIGGS AND FREE-HAND SLICING TECHNIQUES ON TISSUE ULTRASTRUCTURE, WATER AND ELECTROLYTES DURING INVITRO INCUBATION

Slices were prepared from dog myocardium using either a Stadie-Riggs mechanical tissue slicer or a free-hand slicing technique. Slice function and intactness was assessed by measuring the ability of the slices to maintain cell volume and extracellular spaces, and to maintain cell fine structure. Stadie-Riggs slices were capable of many functions during 60 min of in vitro incubation but evaluation of all parameters indicated that they were damaged significantly by the slicing technique. Free-hand slices had smaller insulin and mannitol spaces than Stadie-Riggs slices, were able to regulate cell volume and to establish high intracellular concentrations of K. In addition, direct electron microscopic observations of free hand slices showed most cells retained a normal or near normal ultrastructure, even after 60 min of incubation. Slices cut with the free hand technique are only slightly damaged during preparation and are suitable for in vitro studies of myocardial function.