Altered structure of small cerebral arteries in patients with essential hypertension.
OBJECTIVE
Structural alterations in the microcirculation may be considered an important mechanism of organ damage. An increased media-to-lumen ratio of subcutaneous small resistance arteries has been demonstrated to predict the development of cardiocerebrovascular events in hypertensive patients. Alterations in the structure of small cerebral arteries have been demonstrated in animal models of experimental or genetic hypertension. However, no evaluation with reliable techniques has ever been performed in humans.


METHODS
Twenty-eight participants were included in the present study: they were 13 hypertensive patients and 15 normotensive individuals. All participants underwent a neurosurgical intervention for benign or malign tumors. A small portion of morphologically normal cerebral tissue was excised from surgical samples and examined. Cerebral small resistance arteries (relaxed diameter around 200 mum) were dissected and mounted on an isometric and isobaric myograph, and the tunica media to internal lumen ratio was measured. In addition, cerebral cortical microvessel density (MVD) was also evaluated. The tissue was sectioned and stained for CD31, and MVD was measured with an automated image analyzer (percentage of area stained). Blood pressure values were evaluated, before surgical intervention, by standard sphygmomanometry.


RESULTS
M/L was significantly greater and MVD significantly lower in hypertensive patients than that in normotensive individuals. No difference between groups in collagen content or mechanical properties of cerebral small arteries was observed.


CONCLUSIONS
Our results indicate that structural alterations of small cerebral vessels are present in hypertensive patients compared with normotensive individuals, similar to those previously observed in subcutaneous small arteries.
Rizzoni
Damiano
D
Clinica Medica, Department of Medical and Surgical Sciences, University of Brescia, Brescia, Italy. rizzoni@med.unibs.it
De Ciuceis
Carolina
C
Porteri
Enzo
E
Paiardi
Silvia
S
Boari
Gianluca E M
GE
Mortini
Pietro
P
Cornali
Claudio
C
Cenzato
Marco
M
Rodella
Luigi F
LF
Borsani
Elisa
E
Rizzardi
Nicola
N
Platto
Caterina
C
Rezzani
Rita
R
Rosei
Enrico Agabiti
EA
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002536:Cerebral Arteries / Q000737:chemistry / Q000473:pathology* / Q000503:physiopathology; D003094:Collagen / Q000097:blood; D005260:Female; D006801:Humans; D006973:Hypertension / Q000473:pathology*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D017540:Tunica Media / Q000473:pathology; D014655:Vascular Resistance
D003094:Collagen