抄録
Changes in rat livers after treatment with phenobarbital (PB), β-naphtoflavone (βNF) or 3-methylcholanthrene (MC) was stopped were investigated by biochemical, immunochemical and electron microscopic methods. Repeated injections of each drug led to increases in the relative liver weights, in the microsomal proteins per gram of liver, in the microsomal contents of the total cytochrome P-450, and in the corresponding molecular species of P-450; P-450(PB), when treated with PB and P-450(MC) when treated with either βNF or MC. After cessation of treatment with PB or βNF, decreases in all these contents to what were essentially the control values took place approximately in parallel within 7 days. The apparent half lives of cyto-chrome P-450(PB) and P-450(MC) were calculated from the regression lines of cytochrome P-450 as approximately 15 hours. After treatment with MC, however, all the increases were maintained at approximately the maximal values even after 9 days.
Electron microscopy revealed that the smooth ER, which markedly proli-ferated on PB or βNF treatment, decreased rapidly after the drug treatment stopped, and was accompanied by an increase in the number of autophagosom-es. After treatment with MC, however, the proliferated smooth ER remained even after 9 days.
