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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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Box-and-whisker plot showing carnosinase activity in without dementia (n = 17), AD (n = 13), and MD (n = 7) groups. Comparisons were not significant between without dementia and AD or MD groups, however the difference between the AD and MD groups was significant (p = 0.01).
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Figure 1: Box-and-whisker plot showing carnosinase activity in without dementia (n = 17), AD (n = 13), and MD (n = 7) groups. Comparisons were not significant between without dementia and AD or MD groups, however the difference between the AD and MD groups was significant (p = 0.01).

Mentions: Carnosinase activity for patients without dementia was 14.5 – 78.5 μmol/ml/h, comparable to the adult range determined by Lenney et al. (18 – 72 μmol/ml/h) using the same method [31]. The results of the analysis of variance showed a significant difference in means across groups (p = 0.04). Further analysis showed there was no difference in carnosinase activity between patients without dementia (40.3 ± 15.2 μmol/ml/h) and patients with AD (44.4 ± 12.4 μmol/ml/h) or MD (26.6 ± 15 μmol/ml/h) (Figure 1). However, the difference between the AD and MD groups was significant (mean difference = 17.8 μmol/ml/h, p = 0.01).


Brain type carnosinase in dementia: a pilot study.

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

Box-and-whisker plot showing carnosinase activity in without dementia (n = 17), AD (n = 13), and MD (n = 7) groups. Comparisons were not significant between without dementia and AD or MD groups, however the difference between the AD and MD groups was significant (p = 0.01).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Box-and-whisker plot showing carnosinase activity in without dementia (n = 17), AD (n = 13), and MD (n = 7) groups. Comparisons were not significant between without dementia and AD or MD groups, however the difference between the AD and MD groups was significant (p = 0.01).
Mentions: Carnosinase activity for patients without dementia was 14.5 – 78.5 μmol/ml/h, comparable to the adult range determined by Lenney et al. (18 – 72 μmol/ml/h) using the same method [31]. The results of the analysis of variance showed a significant difference in means across groups (p = 0.04). Further analysis showed there was no difference in carnosinase activity between patients without dementia (40.3 ± 15.2 μmol/ml/h) and patients with AD (44.4 ± 12.4 μmol/ml/h) or MD (26.6 ± 15 μmol/ml/h) (Figure 1). However, the difference between the AD and MD groups was significant (mean difference = 17.8 μmol/ml/h, p = 0.01).

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