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Brain type carnosinase in dementia: a pilot study.

Balion CM, Benson C, Raina PS, Papaioannou A, Patterson C, Ismaila AS - BMC Neurol (2007)

Bottom Line: Carnosinase is a dipeptidase found almost exclusively in brain and serum.The effect of other medical conditions did not remove the significance between the AD and MD groups.Carnosinase activity was higher in patients who regularly exercised (n = 20) compared to those who did not exercise regularly (n = 17)(p = 0.006).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Laboratory Medicine, Hamilton Health Sciences, Hamilton, Ontario, Canada. balion@hhsc.ca

ABSTRACT

Background: The pathological processes underlying dementia are poorly understood and so are the markers which identify them. Carnosinase is a dipeptidase found almost exclusively in brain and serum. Carnosinase and its substrate carnosine have been linked to neuropathophysiological processes.

Methods: Carnosinase activity was measured by a flourometric method in 37 patients attending a Geriatric Outpatient Clinic. There were 17 patients without dementia, 13 had Alzheimer's disease (AD) and 7 had mixed dementia (MD).

Results: The range of serum carnosinase activity for patients without dementia was 14.5 - 78.5 micromol/ml/h. There was no difference in carnosinase activity between patients without dementia (40.3 +/- 15.2 micromol/ml/h) and patients with AD (44.4 +/- 12.4 micromol/ml/h) or MD (26.6 +/- 15 micromol/ml/h). However, levels in the MD group were significantly lower than the AD group (p = 0.01). This difference remained significant after adjusting for gender, MMSE score, exercise, but not age, one at a time and all combined. The effect of other medical conditions did not remove the significance between the AD and MD groups. The MD group, but not the AD group, demonstrated a significant trend with carnosinase activity decreasing with duration of disease (from first recorded date of diagnosis to date of blood collection) (r = -0.76, p = 0.049). There was no association with carnosinase activity and MMSE score in the AD or MD group. Both AD and MD patients on any dementia medication (donepezil, galantamine, memantine) had higher carnosinase activity compared to those not taking a dementia medication. Carnosinase activity was higher in patients who regularly exercised (n = 20) compared to those who did not exercise regularly (n = 17)(p = 0.006).

Conclusion: This exploratory study has shown altered activities of the enzyme carnosinase in patients with dementia.

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Related in: MedlinePlus

Relationship between MMSE score and carnosinase activity with MD (◆, n = 7) and AD (○, n = 13). MMSE score were not related to carnosinase activity for the MD (--, r = 0.55, p = 0.21) or the AD group (----, r = -0.19, p = 0.54).
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Figure 3: Relationship between MMSE score and carnosinase activity with MD (◆, n = 7) and AD (○, n = 13). MMSE score were not related to carnosinase activity for the MD (--, r = 0.55, p = 0.21) or the AD group (----, r = -0.19, p = 0.54).

Mentions: Further analysis of the MD group demonstrated a significant trend with carnosinase activity decreasing with duration of disease (from first recorded date of diagnosis to date of blood collection) (r = -0.76, p = 0.05) (Figure 2). There was a positive association with carnosinase activity and MMSE scores, although not significant (r = 0.55, p = 0.21) (Figure 3). There was no significant association in the AD group between carnosinase activity and duration of disease (r = -0.06, p = 0.86) or with MMSE score (r = -0.19, p = 0.54). Diet containing meat, a source of carnosine, or use of dementia medications (donepezil, galantamine, memantine) was not associated with a difference in carnosinase activity between patients with dementia (AD and MD) and those without dementia (p > 0.05). However, carnosinase values were higher in both AD and MD for the patients on dementia medications compared to those who were not on dementia medications. Significance between groups was reached for AD (p = 0.05), but not for MD (p = 0.59). Diet containing meat did not show a difference within the AD or MD groups. Exercise on the day of blood collection showed no difference between patients with dementia and those without dementia, but exercising three or more times a week was associated with an increase in carnosinase activity (n = 37, p = 0.006) (Figure 4).


Brain type carnosinase in dementia: a pilot study.

Balion CM, Benson C, Raina PS, Papaioannou A, Patterson C, Ismaila AS - BMC Neurol (2007)

Relationship between MMSE score and carnosinase activity with MD (◆, n = 7) and AD (○, n = 13). MMSE score were not related to carnosinase activity for the MD (--, r = 0.55, p = 0.21) or the AD group (----, r = -0.19, p = 0.54).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2200655&req=5

Figure 3: Relationship between MMSE score and carnosinase activity with MD (◆, n = 7) and AD (○, n = 13). MMSE score were not related to carnosinase activity for the MD (--, r = 0.55, p = 0.21) or the AD group (----, r = -0.19, p = 0.54).
Mentions: Further analysis of the MD group demonstrated a significant trend with carnosinase activity decreasing with duration of disease (from first recorded date of diagnosis to date of blood collection) (r = -0.76, p = 0.05) (Figure 2). There was a positive association with carnosinase activity and MMSE scores, although not significant (r = 0.55, p = 0.21) (Figure 3). There was no significant association in the AD group between carnosinase activity and duration of disease (r = -0.06, p = 0.86) or with MMSE score (r = -0.19, p = 0.54). Diet containing meat, a source of carnosine, or use of dementia medications (donepezil, galantamine, memantine) was not associated with a difference in carnosinase activity between patients with dementia (AD and MD) and those without dementia (p > 0.05). However, carnosinase values were higher in both AD and MD for the patients on dementia medications compared to those who were not on dementia medications. Significance between groups was reached for AD (p = 0.05), but not for MD (p = 0.59). Diet containing meat did not show a difference within the AD or MD groups. Exercise on the day of blood collection showed no difference between patients with dementia and those without dementia, but exercising three or more times a week was associated with an increase in carnosinase activity (n = 37, p = 0.006) (Figure 4).

Bottom Line: Carnosinase is a dipeptidase found almost exclusively in brain and serum.The effect of other medical conditions did not remove the significance between the AD and MD groups.Carnosinase activity was higher in patients who regularly exercised (n = 20) compared to those who did not exercise regularly (n = 17)(p = 0.006).

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Laboratory Medicine, Hamilton Health Sciences, Hamilton, Ontario, Canada. balion@hhsc.ca

ABSTRACT

Background: The pathological processes underlying dementia are poorly understood and so are the markers which identify them. Carnosinase is a dipeptidase found almost exclusively in brain and serum. Carnosinase and its substrate carnosine have been linked to neuropathophysiological processes.

Methods: Carnosinase activity was measured by a flourometric method in 37 patients attending a Geriatric Outpatient Clinic. There were 17 patients without dementia, 13 had Alzheimer's disease (AD) and 7 had mixed dementia (MD).

Results: The range of serum carnosinase activity for patients without dementia was 14.5 - 78.5 micromol/ml/h. There was no difference in carnosinase activity between patients without dementia (40.3 +/- 15.2 micromol/ml/h) and patients with AD (44.4 +/- 12.4 micromol/ml/h) or MD (26.6 +/- 15 micromol/ml/h). However, levels in the MD group were significantly lower than the AD group (p = 0.01). This difference remained significant after adjusting for gender, MMSE score, exercise, but not age, one at a time and all combined. The effect of other medical conditions did not remove the significance between the AD and MD groups. The MD group, but not the AD group, demonstrated a significant trend with carnosinase activity decreasing with duration of disease (from first recorded date of diagnosis to date of blood collection) (r = -0.76, p = 0.049). There was no association with carnosinase activity and MMSE score in the AD or MD group. Both AD and MD patients on any dementia medication (donepezil, galantamine, memantine) had higher carnosinase activity compared to those not taking a dementia medication. Carnosinase activity was higher in patients who regularly exercised (n = 20) compared to those who did not exercise regularly (n = 17)(p = 0.006).

Conclusion: This exploratory study has shown altered activities of the enzyme carnosinase in patients with dementia.

Show MeSH
Related in: MedlinePlus