title: Melatonin and tryptophan affect the activity-rest rhythm, core and peripheral temperatures, and interleukin levels in the ringdove: changes with age.
abstract: Aging is known to alter the circadian rhythms of melatonin, serotonin, thermoregulatory responses, cytokine production, and sleep/wakefulness which affect sleep quality. We tested the possible palliative effects of a 3-day administration of melatonin (0.25 or 2.5 mg/kg of body weight [b.w.] to young and old ringdoves, respectively) or tryptophan (300 mg/kg of b.w. to old ringdoves) on these rhythms. Doves are a monophasic, diurnal species; these characteristics are similar in humans. Old animals presented lower melatonin and serotonin levels; higher interleukin (IL)-1beta, IL-6, and tumor necrosis factor alpha values; and reductions in the Midline-Estimating Statistic of Rhythm and amplitude of activity-rest rhythm and in the amplitude of the core temperature rhythm. Melatonin raised serum melatonin levels; tryptophan increased both melatonin and serotonin levels. Melatonin and tryptophan lowered nocturnal activity, core temperature, and cytokine levels and increased peripheral temperature in both groups. Melatonin or tryptophan may limit or reverse some of the changes that occur in sleep-wake rhythms and temperature due to age.
authors.affiliation: Department of Physiology, Faculty of Science, University of Extremadura, Avda. de Elvas, s/n, 06071, Badajoz, Spain. sparedes@unex.es
authors.forename: Sergio D
authors.initials: SD
authors.lastname: Paredes
authors.forename: Ana María
authors.initials: AM
authors.lastname: Marchena
authors.forename: Ignacio
authors.initials: I
authors.lastname: Bejarano
authors.forename: Javier
authors.initials: J
authors.lastname: Espino
authors.forename: Carmen
authors.initials: C
authors.lastname: Barriga
authors.forename: Rubén V
authors.initials: RV
authors.lastname: Rial
authors.forename: Russel J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: Ana B
authors.initials: AB
authors.lastname: Rodríguez
mesh_terms: D000284:Administration, Oral; D000375:Aging / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D010856:Columbidae; D005260:Female; D007378:Interleukins / Q000097:blood*; D008297:Male; D008550:Melatonin / Q000008:administration & dosage* / Q000097:blood; D023421:Models, Animal; D009043:Motor Activity / Q000187:drug effects; D015999:Multivariate Analysis; D011336:Probability; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D012894:Sleep Stages / Q000187:drug effects; D014364:Tryptophan / Q000008:administration & dosage* / Q000097:blood; D014851:Wakefulness / Q000187:drug effects
chemical_list: D007378:Interleukins; D014364:Tryptophan; D008550:Melatonin