The Role Of Melatonin In Alzheimer's Disease And In Lung Infection

Objective To investigate the role of melatonin level and circadian rhythm in Alzheimer's disease (AD) and in lung infection; the correlationship between salivary melatonin level and plasma C-reactive protein(CRP) level in COPD acute phase. Method Total of 12 time points of salivary samples of AD patients and aged controls were collected with salivetten during 24-hour sessions. 1AM and 4AM salivary samples of COPD patients were collected; ventricular postmortem CSF were obtained at autopsy, 1-12 hours after death were collected from 30 subjects (IScases with lung infection, IScontrols). Salivary melatonin levels of aged controls and AD and CSF melatonin levels were measured with fadio immunoassay (RZA) plasma CRP levels of COPD patients were measured with ELISA. The plasma CRP levels of COPD patients were measured with routine way in the detective department of the NO 1 hospital of Anhui Medical University. Results The salivary melatonin of 15 aged controls showed a significant periodic pattern over 24 hours using the BCF to fit the data. The rhythms were variable in each subject, melatonin levels were slowly increased after 19:00h and slowly decreased after 07:00. But the circadian rhythm of salivary melatonin was disappeared in AD patients and the Night time salivary melatonin levels were decreased in AD compared with aged controls (P<0.05). There was no significant difference of CSF melatonin level between subjects died with lung infection and controls (P>0.05). Salivary melatonin levels was negative correlated with plasma CRP levels of COPDpatients in acute phase (P<0.05). Conclusion Salivary melatonin measurement is areliable, sensitive and easy method to monitor the change of melatonin level andcircadion rhythm. AD changes melatonin level and cireadian rhythm melatonin mayplay a role to against infective factors in COPU.