[Sympathetic participation in the control of thyroid function (author's transl)]

Area of Science:

• Endocrinology
• Neuroscience
• Histology

Background:

• Sympathetic innervation is crucial for regulating various physiological processes.
• The thyroid gland's function is known to be influenced by the nervous system, but the specific role of sympathetic innervation requires further elucidation.

Purpose of the Study:

• To investigate the role of sympathetic innervation in thyroid gland function.
• To determine if sympathetic denervation affects thyroid morphology and response to cold stress.

Main Methods:

• Surgical sympathectomy of the left thyroid lobe was performed in guinea pigs by sectioning the inferior thyroid artery.
• Histological, caryometric, and folliculometric analyses were conducted on operated and control thyroid lobes.
• One group of animals was exposed to cold (2°C) prior to tissue collection.

Main Results:

• Operated thyroid lobes exhibited significantly larger cell nuclei and follicles compared to control lobes.
• Cold exposure induced significant increases in nuclei and follicle size in control thyroid lobes.
• The sympathectomized thyroid lobes showed no significant changes in response to cold stress.

Conclusions:

• Sympathetic innervation plays a significant role in maintaining normal thyroid gland function.
• The sympathetic nervous system is critical for the thyroid's adaptive response to cold stress.
• These findings support the hypothesis that sympathetic nerves modulate thyroid activity under both basal and stress conditions.