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Light-Induced Functional Pinealectomy: Expression of MT2 Receptors in Liver Cells of C57BL/6 Mice after Melatonin
S V Michurina1, S I Kolesnikov2,3, I Yu Ishchenko4
1Research Institute of Clinical and Experimental Lymphology - Affiliated Branch of Federal Research Center Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia. michurinasv3000@gmail.com.
Abstract:
We performed an immunohistochemical study of MT2 melatonin receptor expression in the liver of C57BL/6 mice with modeled light-induced functional pinealectomy and after melatonin administration by the indirect avidin-biotin peroxidase ABC method. The animals were kept for 14 days under constant lighting. Intragastric administration of melatonin in physiological doses (1 mg/kg body weight for 14 days) to mice with light-induced functional pinealectomy resulted in a 2-fold increase in the relative expression area of MT2 receptors in liver cells in comparison with that in animals kept under standard lighting conditions, 24-h lighting for 14 days, or 24-h lighting receiving placebo (intragastric administration of 200 ml distilled water). Melatonin treatment had practically no effect on MT2 staining intensity. Our results attest to the important role of MT2 receptors in melatonin synthesis disorders and can serve as the basis for the development of therapeutic strategies aimed at melatonin receptors.
Insights
Melatonin administration significantly increased MT2 receptor expression in mouse liver following light-induced pinealectomy. This finding highlights the role of MT2 receptors in melatonin synthesis disorders.
Area of Science:
- Immunology
- Endocrinology
- Pharmacology
Background:
- Disruptions in melatonin synthesis, often due to altered light exposure, can impact physiological processes.
- The MT2 melatonin receptor plays a role in mediating melatonin's effects.
- Understanding receptor expression is crucial for addressing melatonin-related disorders.
Purpose of the Study:
- To investigate the effect of melatonin administration on MT2 melatonin receptor expression in the liver of mice with light-induced functional pinealectomy.
- To assess the impact of constant light exposure on MT2 receptor levels.
Main Methods:
- Immunohistochemical analysis using the avidin-biotin peroxidase ABC method.
- C57BL/6 mice were subjected to 14 days of constant lighting to model functional pinealectomy.
- Melatonin (1 mg/kg) or placebo was administered intragastrically for 14 days.
Main Results:
- Light-induced functional pinealectomy and constant light exposure altered MT2 receptor expression.
- Intragastric melatonin administration led to a 2-fold increase in the relative expression area of MT2 receptors in liver cells of pinealectomized mice.
- Melatonin treatment did not significantly affect the intensity of MT2 receptor staining.
Conclusions:
- MT2 melatonin receptors are significantly upregulated in the liver under conditions of disrupted melatonin synthesis.
- Melatonin administration can modulate MT2 receptor expression, suggesting a therapeutic target.
- These findings support the development of therapeutic strategies targeting melatonin receptors for melatonin synthesis disorders.
