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NAD+ AND NADH CONCENTRATIONS IN YOUNGER AND OLDER HUMAN ADULTS
Author(s) -
Singhal Ram P,
Zhang Junqian Junqian
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1357
Subject(s) - nad+ kinase , chemistry , biochemistry , enzyme
NADH and NAD + are the most important coenzymes in the biological system. We have studied the concentration of these coenzymes in human serum from different age groups (20 years to 80 years old). Two analytical methods (HPLC and an enzymatic) were developed for this purpose. NADH was found to be very unstable in serum samples even when analyzed immediately after their collection. Serum NADH undergoes oxidation in vitro irrespective of the storage conditions employed. Antioxidants were found to preserve NADH in the reduced state in vitro . Several antioxidants to prevent oxidation of NADH in the serum were thoroughly examined. Vitamin C and coenzyme Q were found to equally stabilize NADH in serum. Recovery of NADH ranged from 90% to 92%. Recovery of NAD + was about 99%. Serum samples from numerous healthy volunteers of various age groups and one from a colon cancer patient were studied. The human serum NADH concentration was found to very small (50 nM to 1.2 μM). The NADH contents and the ratio of NADH to NAD + increased as a function of age. This general trend was common in both healthy male and healthy female individuals (46 yr. to 78 yr.). However, male individuals had slightly higher NADH contents and also a greater ratio of NADH to NAD + . A male colon patient also had higher NADH content and an increased ratio of NADH to NAD + than those of the healthy adults. The higher amount of NADH in the male individuals than the female ones suggests that the metabolic rates is different the two cases. Elevated NADH to NAD + ratio further suggests that older individuals of both sexes are unable to utilize NADH as effectively as the younger adults. This observation has direct bearing on the mitochondrial oxidation. NADH is perhaps not oxidized efficiently in the older and female adults than the younger individuals, i.e. less of the energy pool (ATP) in the older adults. (Research sponsored by Center for Improvement of Human Functionality)