Left ventricular free wall and intraventricular pressure-sarcomere length distributions.
Sarcomere lengths were measured after pentobarbital anesthesia at five sites through the wall of the formaldehyde solution-fixed cadmium-arrested closed-chest rat left ventricle. Sections (250 micron) were cut from endocardium to epicardium with a freezing microtome. Selected sections were sonified, mixed with a gelatin-water solution, and placed on a glass slide. Sarcomere lengths were measured with an optical microscope at five sites through the wall. Sarcomere lengths progressively increased from section I (endocardium site) to section III (middle site) and IV. Sarcomere lengths were again shorter in section V (epicardium site). There was a progressive increase in sarcomere lengths with increasing intraventricular pressures. Sarcomere lengths did not significantly exceed optimum length.
D000818:Animals; D001794:Blood Pressure; D002105:Cadmium Poisoning / Q000503:physiopathology*; D006352:Heart Ventricles; D008297:Male; D008854:Microscopy, Electron; D009206:Myocardium / Q000648:ultrastructure*; D051381:Rats