For Research Use Only – Not for Human Consumption

Abstract

The melatonin receptor type 1 (MT1) is a G protein–coupled receptor (GPCR) that mediates many of the biological effects of melatonin, including circadian rhythm regulation, sleep-wake cycles, and endocrine signaling. This receptor is expressed widely in the brain and peripheral tissues, with key roles in photoperiodic regulation and neuroendocrine processes. Research on MT1 continues to expand due to its implications in sleep disorders, mood regulation, and potential therapeutic targets.

Introduction

Melatonin is a pineal hormone primarily responsible for synchronizing circadian rhythms with the environmental light-dark cycle. MT1, along with MT2, is one of the two high-affinity melatonin receptors identified in mammals. MT1’s primary function is to mediate melatonin’s inhibitory action on neuronal firing and its role in circadian entrainment.

Studying MT1 receptors offers researchers insight into the mechanisms by which melatonin influences neuroendocrine and metabolic functions. MT1 is of particular interest in laboratory studies involving circadian biology, sleep regulation, and metabolic homeostasis.

Chemical Identification

• Primary Ligand: Melatonin
• Melatonin CAS Number: 73-31-4
• MT1 Gene Name: MTNR1A
• Protein Classification: G protein-coupled receptor (GPCR)

Mechanism of Action in Research

MT1 receptors are coupled to inhibitory G proteins (Gi/o), leading to reduced cyclic AMP (cAMP) production when activated by melatonin. This cascade affects neuronal excitability, hormone secretion, and circadian regulation.

Key functions under study:

• Inhibition of adenylate cyclase activity.
• Suppression of neuronal firing in the suprachiasmatic nucleus (SCN).
• Regulation of gonadotropin-releasing hormone (GnRH) secretion in photoperiodic animals.

Applications in Scientific Research

1. Circadian Rhythm Research – Investigating how MT1 modulates the biological clock.
2. Sleep Studies – Examining melatonin’s effects on insomnia and sleep quality.
3. Mood Disorders – Exploring the role of MT1 in depression and seasonal affective disorder (SAD).
4. Metabolic Regulation – Assessing MT1’s contribution to energy balance and glucose metabolism.
5. Neuroprotection – Studying MT1-mediated signaling in oxidative stress and neurodegenerative models.

Safety & Compliance

All materials used for MT1 receptor research, including melatonin and analogs, are not FDA-approved for medical treatment or dietary supplementation within the scope of this paper. These compounds are supplied strictly for laboratory research use only.

References (PubMed/NCBI Examples)

1. Reppert SM, Weaver DR, Godson C. “Melatonin receptors step into the light: cloning and classification of subtypes.” Trends Pharmacol Sci. 1996. [PubMed PMID: 8821845]
2. Dubocovich ML, et al. “International Union of Basic and Clinical Pharmacology. LXXV. Nomenclature, classification, and pharmacology of G protein-coupled melatonin receptors.” Pharmacol Rev. 2010. [PubMed PMID: 20123979]
3. Hardeland R. “Melatonin and its role in circadian rhythmicity.” J Biol Rhythms. 2005. [PubMed PMID: 15851529]

Disclaimer

This material is intended for laboratory research purposes only. It is not for human use, veterinary use, diagnostic, or therapeutic application. All handling should be performed by trained professionals under controlled laboratory conditions.

Frequently Asked Questions (FAQ)

1. What is MT1?
MT1 is a melatonin receptor subtype that regulates circadian rhythms and neuroendocrine signaling.

2. What is the CAS number for melatonin, the primary ligand?
The CAS number is 73-31-4.

3. How does MT1 differ from MT2 receptors?
MT1 primarily mediates neuronal inhibition and circadian entrainment, while MT2 influences phase-shifting and vascular tone.

4. Where are MT1 receptors expressed?
They are found in the brain (especially the suprachiasmatic nucleus), retina, pituitary gland, and peripheral tissues.

5. What signaling pathway does MT1 use?
MT1 activation inhibits adenylate cyclase, decreasing cAMP levels.

6. What research applications involve MT1?
Circadian biology, sleep disorders, depression, neuroprotection, and metabolic regulation.

7. Are MT1-targeted compounds FDA-approved for clinical use?
No. Research compounds targeting MT1 are not approved for human use.

8. Can MT1 modulation affect sleep quality?
Yes, MT1 research suggests it plays a key role in sleep onset and maintenance.

9. Is MT1 involved in metabolic regulation?
Emerging research suggests MT1 signaling influences glucose and energy metabolism.

10. Where can MT1 receptor studies be found?
Published studies are available in PubMed, NCBI, and peer-reviewed pharmacology journals.