Circadian rhythm in hepatic drug metabolizing activity in the rat

Effect of 17‐β‐estradiol and testosterone on aryl hydrocarbon hydroxylase activity in mouse tissues in vivo and in cell culture

“…These enzyme levels are known to vary widely in response to age, sex and species differences (Conney, 1967;Nebert and Gelboin, 1969;Cram et al, 1965), nutritional and hormonal variations (Conney, 1967;Wattenberg et al, 1962); insecticides (Conney, 1967;Fouts, 1963); and even to circadian rhythmicity (Radzialowski and Bousquet, 1967) and exposure to softwood bedding (Vesell, 1967). We attempted to control as many of these variables as possible; howevei, certain experimental difficulties persisted.…”

Annual Differences in Daily Variations in Hepatic Drug Metabolizing Enzyme Activity and Plasma Hormone Levels in the Rat

“…The underlying rea sons for the presence or absence of these rhythms have not yet been elucidated. Studies by Radzialowski and Bousquet (1968) and Lake et al (1976) have suggested a reciprocal relationship between circadian rhythms in hepatic drug metabolism and plasma corticoste rone levels in rats and hamsters. Studies by Jori et al (1971) have suggested that the two above-mentioned parameters are directly relat ed in female rats.…”

Aminopyrine Breath Test and Zonal Hepatic Damage in Rats

“…The rats were fasted overnight before administering l4C-AP. All experiments were started in the morning at 10.00 h to avoid the influence of the diurnal rhythmic variation in hepatic drugmetabolizing activity [14], Under light ether anesthesia, a polyethylene catheter PE-10 was introduced into the right femoral vein of each rat. I h after recovery from anesthesia, a rat was placed in an airtight restraining cage.…”