Melatonin research in mice: a review.

Area of Science:

• Endocrinology
• Animal Models
• Biomedical Research

Background:

• Melatonin's physiological roles and therapeutic potential are extensively studied, with a focus on human research.
• Animal models are vital for biological research, and mice are commonly used in biomedicine.
• However, melatonin research in mice presents unique challenges often overlooked by researchers from other fields.

Purpose of the Study:

• To review existing studies measuring melatonin levels in various mouse strains.
• To identify and address the problem of melatonin deficiency in commonly used laboratory mouse strains.
• To critique the methodologies leading to erroneous results in melatonin research using mice.

Main Methods:

• Comprehensive review of studies measuring melatonin in the pineal gland and blood of different mouse strains.
• Analysis of methodologies, including immunoassay validation and sample preparation techniques.
• Evaluation of the appropriateness of high-dose melatonin administration in experimental settings.

Main Results:

• The majority of laboratory mouse strains do not produce melatonin.
• CBA and C3H mouse strains are exceptions, producing significant melatonin during the dark phase.
• Published studies frequently report inaccurate high melatonin levels due to unvalidated assays and improper sample preparation.

Conclusions:

• Most laboratory mouse strains are melatonin-deficient, a fact often ignored in current research.
• Unreliable assays and inadequate sample preparation lead to erroneous melatonin level reporting.
• The use of melatonin-deficient mice in research, especially with high exogenous doses, requires critical re-evaluation to ensure scientific validity.