Garlic prevents ultrastructural alterations caused by dehydration in mousecerebral microvessels

Dehydration is known to significantly reduce both the time required for the first platelet aggregate and the time to full occlusion in photochemically -induced thrombosis, in vivo. Ultrastructural changes that contribute to su ch events remain unknown. Therefore, the effect of water deprivation for 24 hr, las a model for dehydration) on the ultrastructure of mouse pial micro vessels was investigated. The possible beneficial effect of garlic in preve nting such ultrastructural changes was also investigated. Four groups of TO strain: control, control-garlic treated, dehydrated, and dehydrated-garlic treated male mice, 10/group, were used. Dehydration was induced by water d eprivation for 24 hr. Garlic solution was i.p. injected at 0.1 ml/10g body weight. In urethane-anesthetized (2 mg/g, i.p.) mice, topical and transvess el bimodal fixation of pial microvessels was done with a phosphate buffered mixture of glutaraldehyde and paraformaldehyde, followed by a conventional electron microscopy procedure. Examination of control cerebral pial microv essels showed no evidence of cellular damage. Membranes of endothelial cell s were intact. Within pial microvessels there was no evidence of platelet a ggregation. Garlic treatments did not cause any ultrastructure abnormalitie s in control mice. Compared with control, dehydration caused the appearance of thrombi that consisted of platelet aggregates. Discoid platelets contai ning granules, spheroid degranulated platelets, and those with large pseudo podia were present in 80% of dehydrated mice. The venular endothelial surfa ce of dehydrated mice revealed dilated profiles of endoplasmic reticulum an d variously shaped vacuoles, Swelling of nuclear envelopes and mitochondria l distension were also present in dehydrated mice. Concomitant garlic treat ment prevented most of these ultrastructural changes. These findings demons trated the extent of damage to the pial microvessels in response to water d eprivation and demonstrated the beneficial effect of garlic as a possible m ean of protection against oncoming vascular pathology. Anat Rec 263:85-90, 2001. (C) 2001 Wiley-Liss, Inc.