[ULTRA STRUCTURAL CHARACTERISTIC OF THYROID GLAND IN RATS EXPOSED TO EXOGENOUS CHRONIC HYPERTHERMIA OF MEDIUM DEGREE]

Area of Science:

• Endocrinology
• Environmental Physiology
• Cell Biology

Background:

• High temperatures, from climate and occupational settings, induce detrimental physiological changes.
• Overheating causes lasting structural and functional alterations in the body, potentially leading to destructive processes.

Purpose of the Study:

• To investigate the ultrastructural characteristics of the thyroid gland under prolonged heat exposure (exogenous hyperthermia).

Main Methods:

• Sixty Wistar rats were subjected to chronic hyperthermia (42.0-43.1°C for 5 hours daily over 60 days).
• Control rats were maintained at 21°C.
• Ultrastructural analysis of thyroid glands was performed on days 1, 7, and 15 post-exposure.

Main Results:

• Observed changes included "openwork" thyrocytes, dark nuclei, and reduced apical microvilli.
• Other findings included lack of basal membrane folding, dilated granular endoplasmic reticulum, and deformed organelles.
• Presence of interstitial vesicles with erythrocytes and interfollicular endotheliocytes indicated tissue damage.

Conclusions:

• Prolonged hyperthermia induces significant ultrastructural changes in rat thyroid glands.
• These alterations suggest a functional decrease in thyrocytes, impacting thyroid hormone regulation.