Aging is associated with increased collagen type IV accumulation in the basal lamina of human cerebral microvessels.
BACKGROUND
Microvascular alterations contribute to the development of stroke and vascular dementia. The goal of this study was to evaluate age and hypertension related changes of the basal lamina in cerebral microvessels of individuals, who died from non-cerebral causes.


RESULTS
We examined 27 human brains: 11 young and 16 old patients. Old patients were divided into two subgroups, those with hypertension (n = 8) and those without hypertension (n = 8). Basal lamina changes of the cerebral microvessels were determined in the putamen using antibodies against collagen type IV and by quantitative analysis of vessel number, total stained area of collagen, thickness of the vessel wall and lumen, and relative staining intensity using immunofluorescence. The total number of collagen positive vessels per microscopic field was reduced in old compared to young subjects (12.0+/-0.6 vs. 15.1+/-1.2, p = 0.02). The relative collagen content per vessel (1.01+/-0.06 vs. 0.76+/-0.05, p = 0.01) and the relative collagen intensity (233.1+/-4.5 vs. 167.8+/-10.6, p < 0.0001) shown by immunofluorescence were higher in the older compared to the younger patients with a consecutive reduction of the lumen / wall ratio (1.29+/-0.05 vs. 3.29+/-0.15, p < 0.0001). No differences were observed for these parameters between old hypertensive and non-hypertensive patients.


CONCLUSIONS
The present data show age-related changes of the cerebral microvessels in sections of human putamen for the first time. Due to the accumulation of collagen, microvessels thicken and show a reduction in their lumen. Besides this, the number of vessels decreases. These findings might represent a precondition for the development of vascular cognitive impairment. However, hypertension was not proven to modulate these changes.
Uspenskaia
Olga
O
Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-University, Munich, Germany. olga_uspenskaya@lenta.ru <olga_uspenskaya@lenta.ru>
Liebetrau
Martin
M
Herms
Jochen
J
Danek
Adrian
A
Hamann
Gerhard F
GF
D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001485:Basement Membrane / Q000378:metabolism; D003071:Cognition / Q000502:physiology; D024141:Collagen Type IV / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D006973:Hypertension / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008297:Male; D008833:Microcirculation / Q000378:metabolism; D018613:Microscopy, Confocal; D008875:Middle Aged; D011699:Putamen / Q000098:blood supply*
D024141:Collagen Type IV