The effect of age on the enzyme activities of tryptophan metabolism along the kynurenine pathway in rats

Comai, Stefano; Costa, Carlo Virgilio Luigi; Ragazzi, Eugenio; Bertazzo, Antonella; Allegri, Graziella

doi:10.1016/j.cccn.2005.04.013

Cited by 40 publications

(41 citation statements)

References 69 publications

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“…In a population without detectable neurological disease Kepplinger et al54 and Heyes et al9 observed that CSF KYNA levels significantly increased with advancing age. Consistent with our observation, the activity of the PIC producing enzyme ACMSD has been shown to increase with age in studies of rat kidney, liver and small intestine 55. Unfortunately, an investigation of age-associated changes in ACMSD activity in human tissue is yet to be reported.…”

Section: Biological Factors Influencing Pic Levels In the Cnssupporting

confidence: 89%

The Physiological Action of Picolinic Acid in the Human Brain

Grant

Coggan

Smythe

2009

Int J�Tryptophan�Res

149

116

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Picolinic Acid is an endogenous metabolite of L-tryptophan (TRP) that has been reported to possess a wide range of neuroprotective, immunological, and anti-proliferative affects within the body. However the salient physiological function of this molecule is yet to be established. The synthesis of picolinic acid as a product of the kynurenine pathway (KP) suggests that, similar to other KP metabolites, picolinic acid may play a role in the pathogenesis of infl ammatory disorders within the CNS and possibly other organs.In this paper we review the limited body of literature dealing with the physiological actions of picolinic acid in the CNS and its associated synthesis via the kynurenine pathway in health and disease. Discrepancies and gaps in our current knowledge of picolinic acid are identifi ed highlighting areas of research to promote a more complete understanding of its endogenous function in the brain.

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Section: Biological Factors Influencing Pic Levels In the Cnssupporting

confidence: 89%

The Physiological Action of Picolinic Acid in the Human Brain

Grant

Coggan

Smythe

2009

Int J�Tryptophan�Res

149

116

View full text Add to dashboard Cite

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“…Thus, elevated TDO2 level in one year old rats might anticipate pathological changes. Although Comai et al found a decline in the enzyme activities involved in tryptophan metabolism in old Sprague-Dawley rats compared to 2-3 month old ones [13], it may be explained with methodological differences.…”

Section: Discussionmentioning

confidence: 92%

Increase in Alzheimer's related markers preceeds memory disturbances: Studies in vasopressin-deficient Brattleboro rat

Várga

Klausz

Domokos

et al. 2014

Brain Research Bulletin

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Alzheimer's disease (AD) is the most common form of dementia in the elderly. For more effective therapy early diagnostic markers could be beneficial. Therefore we compared one year old rats with adults and examined if changes in possible brain markers of AD preceeded memory decline. We also tested if vasopressin-deficient animals were useful model of AD as vasopressin has well known positive effect on memory and AD patient has decreased vasopressin production.We compared adult (3 month) and old (12 month), normal and vasopressin-deficient Brattleboro rats. To receive a comprehensive picture about their memory we examined their social discrimination, object discrimination and conditioned learning abilities (shuttle box).Amyloid precursor protein (APP), mitogen-activated protein kinase 1 (MAPK1), β-actin and tryptophan 2,3-dioxygenase 2 (TDO2) mRNA levels was measured by quantitative PCR.There was no difference between the memory of adult and aged groups. The vasopressin-deficient rats at both ages showed a weaker performance in the course of social and object discrimination tests and a higher escape failure during the shuttle box experiment. The brain marker mRNAs of the elder animals were higher than the levels of the adults, but the absence of vasopressin had no influence on them.Thus, the one year old rats showed elevated levels of AD-related markers, but memory deficits were observable only in vasopressin deficient animals. Vasopressin does not seem to have pathogenic role in AD. Changes in the studied markers might predict later symptoms, although further studies are required for confirmation.

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“…The enzyme activities involved in this pathway of tryptophan degradation in rats have been found to decline with age, except for aminocarboxymuconate-semialdehyde decarboxylase. The decrease in the metabolism with age can lead to a lowered biosynthesis of nicotinic acid and NAD, which takes part in almost all biosynthetic pathways in the body [77]. In contrast, Moroni and coworkers found that the levels of kynurenic acid (KYNA) increase with age [78].…”

Section: The Kynurenine Systemmentioning

confidence: 97%