[Effect of low temperatures on the functional state of the membranes of the hepatic endoplasmic reticulum].
Oxidation of fluorescent substrates--NADPH and 4-dimethylamine chalcone (DMC) by microsomes from liver endoplasmic reticulum was studied after freezing and thawing of these cells organelles. Slow freezing to -25 degrees or quick freezing to -196 degrees did not affect distinctly the rate of NADPH oxidation after thawing, but oxidation of DMC by microsomes was decreased in both cases. Freezing and subsequent thawing of microsomes impaired apparently the terminal sites of electron transfer and/or the systems of hydroxylation, including cytochrome P-450. Slow freezing to -25 degrees impaired microsomes more markedly than quick freezing to -196 degrees.
[Effect of low temperatures on the functional state of the membranes of the hepatic endoplasmic reticulum]. Oxidation of fluorescent substrates--NADPH and 4-dimethylamine chalcone (DMC) by microsomes from liver endoplasmic reticulum was studied after freezing and thawing of these cells organelles. Slow freezing to -25 degrees or quick freezing to -196 degrees did not affect distinctly the rate of NADPH oxidation after thawing, but oxidation of DMC by microsomes was decreased in both cases. Freezing and subsequent thawing of microsomes impaired apparently the terminal sites of electron transfer and/or the systems of hydroxylation, including cytochrome P-450. Slow freezing to -25 degrees impaired microsomes more markedly than quick freezing to -196 degrees.