Melatonin
What is the dominant function of melatonin in humans
- Communicate diurnal patterns to the hypothalamus - Reduce muscle activity thus reducing body temperature to induce sleep
The pineal gland regulates
Chronobiologic rhythms (also gonadal function and development in seasonal breeders)
Which structural class of hormone does melatonin belong
Amine
Pineal gland measures
Day length and adjusts melatonin secretion
Melatonin therapy for early riser
Give melatonin before bed
Melatonin therapy for a night owl
Give melatonin in early afternoon
Melatonin inhibits
Gonadotropic hormones LH/FSH via inhibition og GnRH
During spring (mating season)
Gonads become rejuvenated
During winter (non-breeding season)
High melatonin, gonads become inactive
Melatonin is stimulated by
Hypoglycemia and darkness. Duration of melatonin secretion each day is directly proportional to length of darkness
Highest density of melatonin receptors are found
Hypothalamus, Anterior Pituitary, and Retina
Why do patients with rheymatoid arthritis have worsening symptoms in the winter?
Melatonin specifically increases pro-inflammatory cytokines like TNF-alpha
Ia melatonin a major regulator of normal sleep
No, normal function is to help decrease skeletal muscle activity and body temperature to induce sleep
What secretes melatonin
Pineal gland
Animals without a pineal or lesion
Prevents pineal form receiving photoinformation and are unable to prep for breeding
Why do reast cancer patients have low serum melatonin
Studies show that melatonin inhibits growth of breast tissue