Measurements of rat plasma coagulation proteins during prolonged exposure to diethylstilbesterol

The effects of diethylstilbesterol (DES) on concentration of selected plasma coagulation proteins in male rats was studied sequentially over a 28-day period. At the outset of the study, male rats underwent orchiectomy and implantation of a pellet containing DES 5.0 mg or a placebo pellet. At intervals of 7 days, 3 of the animals from each treatment group were sacrificed and blood samples were withdrawn for assay. Plasma concentrations of Factor II (prothrombin) and Factor VII, two vitamin K-dependent coagulation proteins, were significantly decreased in DES-treated animals (approximately 70% normal activity for both Factors) compared to placebo-treated animals. In contrast, Factor VIII activity was higher with DES treatment than with placebo. Plasma concentrations of both antithrombin III (AT III) and plasminogen were decreased in DES-treated animals compared to placebo by immunologic as well as activity assays. Albumin concentrations were not different between the two groups at any point of study, although both were increased at day 21 compared to beginning values. Fibronectin concentrations were slightly decreased in DES-treated animals compared to those which received placebo. The combination of orchiectomy and treatment with DES had profound metabolic effects on the animals; the DES treated animals had a mean body weight loss of 100 g after 28 days, while the placebo group gained an average of 78 g compared to a control group (no surgery) which had average weight gain of 85 g during the 28 day period of study.