Age-Related Changes in Calcitonin-Producing Thyroid C-Cells of Male Wistar Rats

Area of Science:

• Endocrinology
• Gerontology
• Histology

Background:

• Thyroid C-cells produce calcitonin (CT), a key inhibitor of bone resorption.
• Age-related changes in C-cell structure and function are not fully understood.
• Calcitonin's role in bone health may be affected by aging.

Purpose of the Study:

• To investigate age-related structural and functional changes in rat thyroid C-cells.
• To analyze alterations in calcitonin, testosterone, calcium, and phosphorus levels with age.
• To assess the incidence of C-cell hyperplasia and medullary thyroid carcinoma in aging rats.

Main Methods:

• Histomorphometric, ultrastructural, and biochemical analyses were performed on male rats aged 3, 16, and 24 months.
• Calcitonin localization used the peroxidase-antiperoxidase method.
• Stereological analysis with newCAST software and serum analysis for CT, testosterone, calcium, and phosphorus.

Main Results:

• C-cell volume density significantly increased with age.
• Smaller C-cells became more prevalent, larger ones decreased; secretory granules increased in older rats.
• Serum calcitonin rose, while testosterone and phosphorus decreased in older rats; calcium levels dropped in middle-aged rats.

Conclusions:

• Aging induces significant histomorphometric changes in thyroid C-cells.
• Age-related alterations in C-cells and associated hormone levels may impact bone metabolism.
• Increased incidence of C-cell hyperplasia and medullary thyroid carcinoma observed in older rats.