Serum lipoproteins and major apoproteins in Cystic Fibrosis(CF) - effect of short term Cimetidine (C) application

Abstract

H2 receptors are blocked by C. This increases low pH values in gastric and duodenal fluid. In CF the pH in duodenal fluid is in a suboptimal range, resulting in a lowered pancreatic intestinal fat absorption. As a pilot study we administered C (600 mg/m2) daily during 7 days under controlled clinical and dietary observation and studied the plasma lipoprotein and major apoprotein alterations. In addition stool analysis, based on 24 hour excretion of fat and nitrogen, was performed.As compared to controls (triglycerides, TG:62 ± 20,2 mg/100 ml) CF showed increased levels of total- (120 ± 6,1 mg/100 ml) and VLDL-TG, whereas total cholesterol (CH) and LDL-CH were decreased. The finding of low LDL was confirmed by low apoprotein-B (apo-B) levels in CF. HDL-CH as well as the major apoproteins of the HDL-fraction Al + A2 were both decreased in CF. After C administration total TG and VLDL-TG showed a further increase. On the other hand total-and LDL-CH as well as apo-B were slightly decreased by drug treatment. Stool fat and nitrogen excretion were diminished in parallel, suggesting a better absorption of nutrient fat under C treatment. Pulmonary side effects under short time C application were not seen but must be considered in a long term application trial.