Maynard B. Chenoweth

Effects of Chloroform, Halothane and Methoxyflurane on Human Liver Cells in Vitro

Morphologic and certain functional effects of chloroform, halothane, and methoxyflurane on cultures of human hepatic cells (Chang) are reported. Phase-contrast photomicrography and time-lapse cinematography revealed varying degrees of toxic reactions characterized by intracytoplasmic vacuolization and changes in cytoplasmic activity. At clinically useful concentrations, chloroform caused minimal reversible damage in most cells while with halothane and methoxyflurane disturbing effects on cell morphology and cytoplasmic function were virtually absent. In excessive concentration, chloroform produced generalized permanent cell damage, while with halothane only a fraction of the cells underwent disintegration. Methoxyflurane could not adequately be assessed because of the limited solubility of the drug in the tissue culture medium.

The T Deflection of Isolated Mammalian Heart Muscle Electrogram

Both bipolar and unipolar electrograms recorded from well-oxygenated isolated papillary muscle preparations consist of R and T deflections in the same direction. The T is inverted by anoxia, rapid late, and injury. When cut linear strips of ventricular muscle are observed for many hours, during which time they presumably recover from the initial injury, the T deflection becomes upright in most cases, and then can be depressed and inverted by anoxia or rapid rates of stimulation. Since, in the absence of modifying factors, the T is in the same direction as the R deflection in a simple linear strip, it probably cannot be adequately explained on the basis of membrane repolarization. Since the nerve after-potentials are believed to represent processes involving oxidative metabolism, the T deflection may also be produced by metabolic processes, although the possibility cannot be excluded that it represents a combination of membrane repolarization and other processes.