In vivo visualization of bonghan ducts inside blood vessels of mice by using an Alcian blue staining method.

An in vivo method using Alcian blue (AB) was developed for visualizing floating threadlike tissues inside blood vessels of mice. These novel structures called intravascular Bonghan ducts (IBHDs) are considered as extension of acupuncture meridians. For in vivo imaging of IBHDs, AB solution (pH 7.4) that stains mucopolysaccharides like hyaluronic acid was used. After injecting AB solution into the femoral vein of a mouse, the threadlike structures, stained deep blue, inside the inferior vena cava. The histological results, such as hematoxylin, eosin, and AB staining, show the compositions of the cells and the extracellular matrix in the IBHD. Further studies are needed to investigate their physiological functions, especially in relation with those of other circulatory systems.

Estudo da reatividade vascular induzida pelo estresse mental na gravidez de mulheres portadoras de estenose mitral / Vascular reactivity response to mental stress in pregnant women with mitral stenosis

OBJETIVO: Estudar a reatividade vascular mediante a análise do fluxo sangüíneo e da resistência vascular periférica em repouso e estresse mental na gravidez de mulheres com estenose mitral. MÉTODOS: Foram estudadas 22 mulheres portadoras de estenose mitral, 13 grávidas (GE) e 9 não-grávidas (EM), e 9 gestantes saudáveis voluntárias (GN). Na gestação, 9 (GEB) das 13 do GE necessitaram de betabloqueador e 4 restantes (GESB) evoluíram sem medicação. A plestimografia em repouso e sob estresse mental analisou o fluxo sangüíneo muscular, resistência vascular periférica (RVP), pressão arterial média (PAM) e freqüência cardíaca (FC) na gestação e no puerpério. RESULTADOS: Na gestação do GESB, os valores do fluxo sangüíneo muscular e da FC foram maiores em 1,6 por cento e 20,5 por cento (p = 0,05), e os da RVP e da PAM foram menores em 19,3 por cento e 4,4 por cento, respectivamente, em comparação ao puerpério; no estresse mental, o fluxo sangüíneo muscular aumentou em 55,9 por cento, a FC reduziu em 30,2 por cento e houve semelhança da RVP e PAM. No GEB, os valores do fluxo e da FC foram maiores em 5,9 por cento e 14,9 por cento (p = 0,001) e os da PAM e da RVP menores em 10,3 por cento e 9,1 por cento, respectivamente, quando comparados ao puerpério; no estresse mental o fluxo e a PAM aumentaram em 69,8 por cento e 174,1 por cento, respectivamente, a FC foi semelhante e a RVP reduziu em 53,7 por cento. O estudo comparativo mostrou que no grupo GN o fluxo sangüíneo muscular foi maior, a RVP menor e houve semelhança na PAM e FC em relação ao grupo GE e que os grupos GE, GN, EM apresentaram semelhança na resposta ao estresse mental. CONCLUSÕES: A reatividade vascular na gestação de mulheres com estenose mitral foi preservada e a análise das medidas mostrou valores menores de fluxo sangüíneo muscular e maiores da RVP quando comparados às gestantes saudáveis.

Expression of leptin receptor (Ob-R) in human atherosclerotic lesions: potential role in intimal neovascularization

Neovascularization of the adventitial vasa vasorum with extension into the intima of atherosclerotic lesions is frequently observed, but its pathophysiological significance is still subject to debate. Recently, leptin, the product of the Ob gene, was identified. Leptin, via activation of the endothelial receptor (Ob-R), generates a growth signal involving a tyrosine kinase-dependent intracellular pathway and promotes angiogenic processes. We hypothesized that a high concentration of leptin within vasa vasorum and plaque itself, may influence inflammatory and vascular neovascularization coupling with functional upregulation of the vascular endothelial growth factor (VEGF). Microscopic computerized tomography was utilized for the spatial distribution of vasa vasorum and intimal neovascularization from atherosclerotic human coronary arteries. Atherosclerotic coronary arteries showed a dense plexus of microvessels in the adventitia and plaque itself. Microscopic analysis from human atherosclerotic aortas revealed an increase in the intimal thickness with neovascularization. The immunoreactivity for Ob-R, VEGF and matrix metalloproteinase (MMP) increased in atherosclerotic plaque, predominantly in the endothelial lining of the intimal neovessel and macrophages/foam cells. Our observation of a prominent colocalization between Ob-R, VEGF and MMP supports this hypothesis and these factors participate in the neovascularization of atherosclerotic lesions. The present study is the first report on vascular tissue and it opens a promising perspective concerning future investigations of leptin-dependent modulation of atherogenesis and vascular neovascularization under pathophysiolgical conditions.

Three dimensional structures of pulmonary elastin; airway vs vascular elastin

Elastin is known to occur in the lung parenchyma and pleura as well as in the pulmonary vessels, but no detailed studies of this elastin's linkage between them have been done in three dimensions. For many years we have known that there is abundant elastin in the mammalian lungs, which may be associated with etiology of causing emphysema. We have developed selective casting methods to allow us to determine the location where elastin is found morphologically. The method involves casting either the vasculature via the right ventricle, or the airways via the trachea in the air sacs. Studies of the vasculature were done with the lung inflated to 80% of the vital capacity. The casted lungs were then put in 0.1 N NaOH at 75 degrees C for 48 hours, turning them frequently. THis method removed all non-elastin tissues. The scanning electron microscopy (SEM) was used to reveal the three dimensional pictures of elastin structures from both lung parenchyma and pulmonary vessels. Elastin was seen as fenestrated sheets and some fibers in both the vessels and the airways. Elastin in the two different locations was often interconnected. Studies on 6 dogs, 8 rabbits, and 2 pigs showed no significant species difference at the level of resolution of the SEM, which was used to study the specimens after they had been freeze-dried.