Monooxygenase activity of human liver in microsomal fractions of needle biopsy specimens.

Abstract

1 Methods are described for the determination of mixed function oxidase activity in microsomal fractions from percutaneous needle biopsies of human liver. 2 Activities of needle biopsy samples were comparable with those of wedge biopsy sample obtained at laparotomy from different subjects. 3 Although cytochrome P‐450 content of liver from rat and man was similar, human AHH activity was only 10% of that in the rat. 4 In biopsies with preserved hepatic architecture, AHH activity and cytochrome P‐450 content showed a significant positive correlation. 5 Cigarette smoking significantly increased both AHH activity and turnover number, but not cytochrome P‐450 content, of biopsies with normal architecture. 6 The presence of liver disease caused a significant decrease in AHH activity and cytochrome P‐450 content.

The effect of alcoholic cirrhosis on the activities of microsomal aldrin epoxidase, 7‐ethoxycoumarin O‐de‐ethylase and epoxide hydrolase, and on the concentrations of reduced glutathione in human liver.

“…Similarly, Boobis et al (1980) have shown that activity of microsomal NADPH cytochrome c-reductase is unaltered by the presence of severe.liver disease.…”

Coordination of Histamine H₃ Receptor Antagonists with Human Adrenal Cytochrome P450 Enzymes

“…Tissue preparation and performance of optical difference spectroscopy were based on methods described in Boobis et al [23], LaBella et al [14] and Whysner and Harding [16].…”

H3 receptor antagonist, thioperamide, inhibits adrenal steroidogenesis and histamine binding to adrenocortical microsomes and binds to cytochrome P450

“…The K, and Hill values are reported with their corresponding standard errors and standard deviations, respectively. Microsomes from bovine adrenal cortex were prepared in 250 mM KPO4, 150 mM KCI and 1 mM EDTA pH 7.25 and suspended in a 50 mM KPO4, pH 7.25 buffer at 0.5 to 1.0 mg protein ml-' in 1.3 or 3.0 ml quartz cuvettes for spectral determinations (Boobis et al, 1980). Substrates diluted in KPO4 buffer were added in 3 to 5 tl aliquots with equal volumes of buffer added to the reference.…”