Abstract:
Background: Numerous studies have reported a relationship between oral contraceptives use
and cardiovascular disease, altered levels of coagulation factors and thrombosis. The goal of
this study was to examine the effect of Combined oral contraceptive (COC, Duofem) on some
physiological parameters and elucidate possible mechanism of action in female wistar rats.
Methods: Forty (40) female wistar rats aged 10-12 weeks weighing 180-250 g were used for
the study. They were divided into four groups (A-D) of 10 rats each comprising 5 treated and 5
control rats. The treated rats received (by intragastric administration), 0.6mg/kg body weight
of COC for 36, 48, 60 and 72 days in five-day cycles (four-days treatment with one-day
break). The COC was given in 5-day cycles (4-day treatment with 1-day break). An
autoanalyzer was used to perform a complete blood count (CBC or FBC). Enzyme-linked
immunosorbent assay (ELISA) was used for the quantitative determination of Protein C and S
Antigen in citrated rat plasma. Antithrombin (AT) was determined by Chromogenic Assays.
Prothrombin time (PT), Activated partial thromboplastin time (APTT) were performed using
Sysmex CA-6000 Coagulation Analyzer. Serum electrolytes were determined using Audicom
AC99000 and liver function tests by ELISA method. Erythropoietin was determined using rat
EPO ELISA kit. Fibrinogen was estimated by Clauss Assay. Results: There were significant
decreases in haemoglobin (Hb), packed cell volume (PCV), Red blood cell (RBC) count, white
blood cell (WBC) counts, lymphocytes (L), prothrombin time (PT) concentration, fibrinogen
(Fib) concentration, antithrombin (AT) concentration , protein C (PC), protein S (PS),
interleukin-6 (IL-6) and interleukin-11 (IL-11) in all treated groups compared to controls (P<
0.05, respectively); in contrast, activities of alkaline phosphate (ALP), aspartate
aminotransferase (AST), and alanine aminotransferase (ALT) as well as sodium and potassium
were increased. There were no significant changes in APTT, mean platelet volume (MPV),
EPO concentration, MCH, MCV, MCHC, Neutrophil, Eosinophil, Basophil, Bicarbonate and
Chloride in all treated groups compared to controls. Most of the changes in the Physiological
parameters were observed in long term exposure group C and group D. Conclusion: Long
term used of combined oral contraceptives may lead to more complications than short time
use. COC users should be monitored for some physiological parameters.
