X-Message-Number: 29830
Date: Thu, 13 Sep 2007 11:15:22 -0700 (PDT)
From: 
Subject: centenarians enjoy a melatonin advantage

[The antiaging effect of melatonin found in rodents may also be operative
in humans.]

Exp Gerontol. 2007 Jul 4; [Epub ahead of print]
Neuroendocrine features in extreme longevity.
  Ferrari E, Cravello L, Falvo F, Barili L, Solerte SB, Fioravanti M,
Magri F; the Italian Multicenter Study on Centenarians (IMUSCE).
Department of Internal Medicine and Medical Therapy, Geriatrics Unit,
University of Pavia, Via Emilia 12, 27100 Pavia, Italy.
  In order to evaluate the effects of some neuro-endocrine changes
during aging we have studied adrenal, thyroid and pineal secretion in
young, healthy old and centenarians. The number of subjects in each
hormone group varied.The following parameters were evaluated: serum
levels of cortisol, dehydroepiandrosterone-sulfate (DHEAS), free
triiodothyronine (FT3), thyroxine (FT4), reverse triiodothyronine
(rT3) and thyroid-stimulating hormone (TSH). Urinary 6-
hydroxymelatonin sulfate (aMT6s) and free cortisol were measured twice
daily.Centenarians exhibited significantly lower TSH levels together
with slightly higher rT3 levels than old controls. These changes could
be due to reduced 5'-deiodinase activity occurring also in absence of
substantial changes of the nutritional pattern.Morning serum cortisol
levels were found to be similar in the 3 age groups, whereas the
decline of serum DHEAS levels was well evident also after the ninth
decade of life. The cortisol/DHEAS molar ratio, which usually
increases with age and considered to be an expression of a neurotoxic
pattern of the steroidal milieu in the central nervous system, did not
shown any further increase in centenarians. The urinary free cortisol
and aMT6s excretion declined with age; however only in centenarians
and in young controls aMT6s excretion was significantly higher at
night than during the day. These findings suggest that the circadian
rhythm of melatonin secretion is maintained in centenarians and, based
on the limitations of this study, could be considered one factor in
successful aging.
PMID: 17764865

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