Presentation Description

No description available.


By: vishapasuvaligam (33 month(s) ago)

pl send me a copy of ppt presentation on melatonin

By: vishapasuvaligam (33 month(s) ago)

very informative and good presentation giving a overall idea regarding melatonin

Presentation Transcript

A Seminar on melatonin hormone:

A Seminar on melatonin hormone Presented By- Kuldeep Kinja M Pharma 2 nd Yr Pharmacology

Slide 2:

Melatonin also known chemically as N -acetyl-5-methoxytryptamine . Is a naturally occurring compound found in animals, plants, and microbes. In animals,circulating levels of the hormone melatonin vary in a daily cycle. Allowing the entrainment of the circadian rhythms of several biological function . It produced in the pineal gland which is outside of the blood-brain barrier acts as an endocrine hormone since it is released into the blood melatonin produced by the retina and the gastrointestinal (GI) tract INTRODUCTION

Slide 3:

Many biological effects of melatonin are produced through activation of melatonin receptors powerful antioxidant, with a particular role in the protection of nuclear and mitochondrial DNA Known as the "hormone of darkness", it is secreted in darkness in both day-active (diurnal) and night-active (nocturnal) . It may also be produced by a variety of peripheral cells such as bone marrow cells, lymphocytes and epithelial cells.

Slide 4:


Melatonin receptors:

Melatonin receptors Found in central nervous system and peripheral tissues In brain MT1 AND MT2 receptors are found in membranes of neurons of (SCN). MTI AND MT2 are G-protien-couple receptors. MT3 receptor is also found which is poorly understood.

G-protein couple receptor:

G-protein couple receptor They also called the metabotropic receptor. Have three subunits 1-Alpha 2-beta 3-gamma Seven transmembrane receptors. Called Heptahelical receptor

Slide 8:

Working of G-protein Receptor

G-protein couple receptor effector system:

G-protein couple receptor effector system 1- Adenylate cyclase/C-AMP sytem 2- phospholipase C / inositol phosphate system

Mechenisum of MT1 receptor:

Mechenisum of MT1 receptor

Mechenisum of MT2 receptor:

Mechenisum of MT2 receptor

Agonist of melatonin receptor :

Agonist of melatonin receptor Very few have been discovered 1-Ramelteon selective for MT1 & MT2 is approved for treatment of insomnia. 2- luzindole 3- 4P-ADOT



Slide 14:

MELATONIN IN PLANTS In plants involve regulation of their response to photoperiod, defense against harsh environments, and the function of an antioxidant. Melatonin has been reported in foodstuffs including bananas and grapes, rice and cereals, herbs, olive oil, wine and beer. While no food has been found to elevate plasma melatonin levels in humans,when other animals consume melatonin-containing food, blood levels of melatonin do increase


MELATONIN IN ANIMALS Melatonin can suppress libido by inhibiting secretion of (LH) and (FSH) especially in mammals that have a breeding season when daylight hours are long. The reproduction of long-day breeders is repressed by melatonin and the reproduction of short-day breeders is stimulated by melatonin.

In Human:

In Human The melatonin signal forms part of the system that regulates the sleep-wake cycle. Infants melatonin levels become regular in about the third month after birth, with the highest levels measured between midnight and (8 AM). In humans, 90% of melatonin is cleared through the liver, a small amount is excreted in urine and a small amount is found in saliva.

Light dependence:

Light dependence Production of melatonin by the pineal gland is inhibited by light and permitted by darkness. SO called "the hormone of darkness“. Its onset called the Dim-Light Melatonin Onset (DLMO). Secretion in blood peaks in the middle of the night, and gradually falls during the second half of the night. When used several hours before sleep, the compound shifts the circadian clock earlier, thus promoting earlier sleep onset and morning awakening.

Slide 18:

Cont… It is principally blue light, around 460 to 480nm that suppresses melatonin. Kayumov showed that light containing only wavelengths greater than 530 nm does not suppress melatonin in bright-light conditions Use of blue-blocking goggles the last hours before bedtime advised for people who need to adjust to an earlier bedtime, as melatonin promotes sleepiness.

Melatonin as antioxidant:

Melatonin as antioxidant The discovery of melatonin as an antioxidant was made in 1993. Melatonin is a direct scavenger of OH, and NO. Melatonin once oxidized cannot be reduced to its former state because it forms several stable end-products upon reacting with free radicals. Called terminal or suicidal antioxidant.


MELATONIN IN IMMUNE SYSTEM immunological effect is thought to result from melatonin acting on high affinity receptors (MT1 and MT2). melatonin may enhance cytokine production melatonin might be useful fighting infectious disease including viral, such as HIV and bacterial infections, and cancer. Endogenous melatonin in human lymphocytes has been related to interleukin-2 (IL-2) production.


MELATONIN IN DREAM Increase in vivid dreaming. 2 to10 mg increase the propensity of falling seep . 80mg can induce sleep in adult man. Extremely high doses of melatonin (50 mg) increased REM sleep time . Many drugs such as cannabis increase melatonin synthesis.




REFERENCES RANG & DALES “PHARMACOLOGY” sixth edition , churchill livingstone Publishers,page-no-503 to 504. Katzung.g,trevor.j “basic and cilinical pharmacology” 11 th edition,Tata McGraw-Hill publishers,page-no-1023to1025. Gillman’s & Goodman’s “the pharmacological basics of therapeutics” Edition 10 th , McGraw-hill Medical publishing division,page no-270.

Slide 24: