Effect of progestin on thyroid function in female Wistar rats

Area of Science:

• Endocrinology
• Reproductive Biology
• Thyroid Research

Background:

• Female hormones, particularly progestins in oral contraceptives, can influence thyroid function.
• Understanding these effects is crucial for women's health and managing potential thyroid dysfunction.

Purpose of the Study:

• To investigate how extra progestin from oral contraceptives affects thyroid function in female rats.
• To characterize the influence of specific progestins (levonorgestrel and desogestrel) on thyroid hormone levels and thyroid tissue.

Main Methods:

• Sixty female Wistar rats were divided into six groups, receiving varying doses of levonorgestrel or desogestrel via gavage for one month.
• Statistical analysis included one-way ANOVA and the Kruskal-Wallis test to compare experimental groups with controls.

Main Results:

• Progestin administration significantly lowered serum free thyroxine (T4) and thyroid-stimulating hormone (TSH) levels.
• Serum free triiodothyronine (T3) levels also decreased after desogestrel exposure.
• Progestin exposure upregulated thyroid-stimulating hormone receptor and sodium iodide symporter expression, and reduced thyroid hormone antibody concentrations.

Conclusions:

• Progestin stimulation can lead to thyroid dysfunction by altering thyroid hormone levels and receptor expression.
• These hormonal changes induce pathomorphological alterations in rat thyroid tissues, highlighting potential risks associated with progestin-containing contraceptives.