Thyroid Pathological Consequences Induced by Caffeine in Female Rats

Abstract

Objective: this study was designed to investigate the histopathological changes induced by caffeine on
thyroid, liver and kidneys in female rats. Caffeine is a central nervous stimulant of methyl xanthine class of
drugs, it has many hormonal and metabolic effects.
Method: twenty-four adult female rats was split in to four equal categories of 6 rats in each group as the
following: Group1,control group received distilled water only by oral gavage. Group2, received 35mg\kg of
caffeine solution. Group3, received 75mg\kg of caffeine and Group4, received 150mg\kg of caffeine. The
experiment continued for 40 days. After 24 hours of the end of experiment, the animals were sacrificed and
blood has been withdrawn from vena cava to prepare serum for hormonal analysis, whereas liver, kidneys
and thyroid were excised and fixed in formalin solution for histopathological processing.
Results: caffeine ingestion cause significant reduction in thyroid function (reduction in T3, T4 and TSH)
in all treated groups compared to control group in addition histopathological study show enlargement of
thyroid follicle with thinning of lining epithelium of acini, vacuolation of both renal tubules, hepatocytes
and vascular congestion of these organs.
Conclusion: Caffeine consumption in high doses causes many histologic and hormonal effects in the studied
organs.