title: Negative correlation of age and the levels of pineal melatonin, pineal N-acetylserotonin, and serum melatonin in male rats.
abstract: Pineal concentrations of N-acetylserotonin and melatonin and serum levels of melatonin were studied in 3-wk-old (prepubertal), 8-wk-old (adult), and 17-mo-old (senile) male rats. They were adapted to a photoperiod of 12 h light/12 h darkness for a minimum of 1 wk and killed at mid-light and mid-dark. Melatonin and N-acetylserotonin were determined by radioimmunoassay. The concentrations of pineal N-acetylserotonin and melatonin were high in the dark period and low in the light period. Statistical analysis indicated that pineal N-acetylserotonin and melatonin levels per 100 gm body weight declined with age. Similarly, serum melatonin demonstrated diurnal changes in all the age groups studied. In addition, there was a significant reduction in the levels of serum melatonin with age. The parallel patterns of decrease in pineal and serum melatonin levels with age suggest a decline in pineal secretion of melatonin in the older animals.
mesh_terms: D000367:Age Factors; D000375:Aging; D000704:Analysis of Variance; D000818:Animals; D002940:Circadian Rhythm; D008297:Male; D008550:Melatonin / Q000032:analysis* / Q000097:blood; D010870:Pineal Gland / Q000032:analysis* / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains / Q000097:blood / Q000378:metabolism*; D012701:Serotonin / Q000031:analogs & derivatives* / Q000032:analysis; D012741:Sexual Maturation
chemical_list: D012701:Serotonin; D008550:Melatonin; C006389:N-acetylserotonin