ENDOCRINE DISTURBANCES INDUCED BY LOW-DOSE ORGANOPHOSPHATE EXPOSURE IN MALE WISTAR RATS

Area of Science:

• Endocrinology
• Toxicology
• Neuroscience

Background:

• Organophosphate (OP) exposure is known to induce various endocrine dysfunctions.
• Understanding the acute hormonal effects of OPs is crucial for assessing their toxicological impact.

Purpose of the Study:

• To investigate the acute effects of cholinesterase inhibition via organophosphate exposure on key hormonal axes in weanling rats.
• To assess changes in cortisol, thyroid hormones (free triiodothyronine, thyroxine), thyroid-stimulating hormone (TSH), and prolactin levels.

Main Methods:

• Thirteen weanling Wistar rats were used.
• Baseline levels of butyrylcholinesterase (BChE), cortisol, free T3, T4, TSH, and prolactin were measured.
• Chlorpyrifos was administered, and hormonal parameters were re-assessed post-exposure.

Main Results:

• Organophosphate exposure significantly decreased BChE activity (p<0.001).
• Cortisol levels significantly increased post-exposure (p<0.01).
• Free triiodothyronine, thyroxine, and TSH levels showed significant increases (p<0.001 for TSH), suggesting central thyroid axis stimulation.
• Thyroxine levels were inversely correlated with cortisol (p=0.01).

Conclusions:

• Acute cholinesterase inhibition by organophosphates can lead to significant hormonal disturbances, including elevated cortisol and thyroid axis activation.
• These findings suggest that acute OP exposure in young animals may mimic hormonal changes seen in shock patients.
• This study provides novel insights into the acute endocrine effects of low-dose OP exposure in weanling animals.