ABSTRACT
Administration of caffeine or theophylline, 0.2 mg/ml (an average of 20 mg/kg/d) of drinking water, to male CD rats, 2 months of age, over a 15 week period resulted in the elevation of liver RNA polymerase I activity by 2-3 fold as assayed in isolated nuclei. This increase in activity was already apparent by the fourth week of exposure. The changes in RNA polymerase I activity were accompanied by moderate liver hypertrophy.
Subject(s)
Caffeine/toxicity , DNA-Directed RNA Polymerases/analysis , Liver/enzymology , RNA Polymerase I/analysis , Theophylline/toxicity , Animals , Drinking/drug effects , Hypertrophy , Liver/drug effects , Liver/pathology , Male , Rats , Rats, Inbred StrainsABSTRACT
Elastase and lipid levels of the plasmas of subjects and of those who have suffered a stroke have been measured, and it has been shown that the normal age related fall in elastase content is mirrored more closely by the fall in high density lipoprotein cholesterol than by changes in total cholesterol. After a stroke a peak level of the elastase concentration is reached later than the peak of the total cholesterol, but before the peak for the HDL-cholesterol is attained. Highest levels of the ratio of these two (a major risk factor in vascular disease) appear to precede both the stroke and the elevation of the elastase level at ages below 76 whereas at higher ages than this the elevation of elastase precedes the lipid changes. It is therefore deduced that the whole question of elastolytic activity in the plasma is intimately bound up with the lipid content of the plasma and with the age of the subject as mirrored in the status of the elastic tissue in the vessel wall.
