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.
Animal ; Blood Vessels/metabolism/ultrastructure ; Corrosion Casting ; Dogs ; Elastin/*ultrastructure ; Lung/blood supply/*metabolism ; Microscopy, Electron, Scanning ; Pulmonary Alveoli/metabolism/ultrastructure ; Rabbits ; Swine

OBJECTIVETo study the effects of enhanced external counterpulsation (EECP) on the vascular morphology, and endothelial function using experimentally induced hypercholesterolemic pigs.

METHODSThirty five male pigs were randomly divided into three groups: 7 normal control animals, 11 hypercholesterolemic animals, and 17 hypercholesterolemic animals receiving EECP. Serum cholesterol was measured. The coronary arteries and aortas were sampled for histopathologic and ultrastructural examination. The NF-kappaB protein expression of porcine coronary arteries was investigated by immunofluorescence.

RESULTSCompared with the normal controls, serum cholesterol levels were significantly higher in the hypercholesterolemic animals with or without EECP. The plaque/intimal area ratio of the aorta decreased significantly in animals receiving EECP [(3.33 +/- 2.40)%, versus (12.03 +/- 7.12)% in those without EECP, P < 0.05]. Lipid deposition, endothelial damage and proliferation of smooth muscle cells were less severe in animals receiving EECP than those not. Moreover, activation and expression of NF-kappaB also decreased significantly (P < 0.05) in animals receiving EECP.

CONCLUSIONSEECP improves the morphology and function of vascular endothelium, and retards the development and progression of atherosclerosis, likely through the inhibition of NF-kappaB signaling pathway.

Animals ; Aorta, Abdominal ; metabolism ; pathology ; ultrastructure ; Atherosclerosis ; blood ; metabolism ; pathology ; Cholesterol ; blood ; Coronary Vessels ; metabolism ; pathology ; ultrastructure ; Counterpulsation ; methods ; Endothelial Cells ; metabolism ; pathology ; Hypercholesterolemia ; blood ; metabolism ; pathology ; Lipoproteins, LDL ; blood ; Male ; Microscopy, Confocal ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Muscle, Smooth, Vascular ; metabolism ; pathology ; NF-kappa B ; metabolism ; Random Allocation ; Swine

OBJECTIVE: To investigate the structural characteristics of the cerebral small vessels with an unknown type of pathological lesion (UTPL). METHODS: Contents of beta-amyloid, alpha-actin and collagen IV in cerebral small vessels with UTPL were studied by Congo red staining, immunohistochemical staining and computer image analysis. RESULTS: The low expression levels of alpha-actin and collagen IV (P<0.05) were observed in tunica media of the vessels with UTPL, and no positive expression of beta-amyloid (P>0.05) was observed in these vessel walls. The expressions of proteins mentioned above in UTPL were different from those of cerebral amyloid angiopathy(CAA) and hyaline arteriolosclerosis. CONCLUSION UTPL was different from CAA or hyaline arteriolosclerosis in pathologic feature.
Actins/metabolism* ; Amyloid beta-Peptides/metabolism* ; Autopsy ; Blood Vessels/ultrastructure* ; Brain/pathology* ; Cerebral Amyloid Angiopathy/pathology* ; Collagen Type IV/metabolism* ; Humans ; Image Processing, Computer-Assisted ; Immunohistochemistry ; Staining and Labeling ; Subarachnoid Hemorrhage/pathology*

The integrity of blood vessels controls vascular permeability and extravasation of blood cells, across the endothelium. Thus, the impairment of endothelial integrity leads to hemorrhage, edema, and inflammatory infiltration. However, the molecular mechanism underlying vascular integrity has not been fully understood. Here, we demonstrate an essential role for A-kinase anchoring protein 12 (AKAP12) in the maintenance of endothelial integrity during vascular development. Zebrafish embryos depleted of akap12 (akap12 morphants) exhibited severe hemorrhages. In vivo time-lapse analyses suggested that disorganized interendothelial cell-cell adhesions in akap12 morphants might be the cause of hemorrhage. To clarify the molecular mechanism by which the cell-cell adhesions are impaired, we examined the cell-cell adhesion molecules and their regulators using cultured endothelial cells. The expression of PAK2, an actin cytoskeletal regulator, and AF6, a connector of intercellular adhesion molecules and actin cytoskeleton, was reduced in AKAP12-depleted cells. Depletion of either PAK2 or AF6 phenocopied AKAP12-depleted cells, suggesting the reduction of PAK2 and AF6 results in the loosening of intercellular junctions. Consistent with this, overexpression of PAK2 and AF6 rescued the abnormal hemorrhage in akap12 morphants. We conclude that AKAP12 is essential for integrity of endothelium by maintaining the expression of PAK2 and AF6 during vascular development.
A Kinase Anchor Proteins/*genetics/metabolism ; Animals ; Blood Vessels/abnormalities/*embryology/metabolism ; Cell Cycle Proteins/genetics/metabolism ; Down-Regulation ; Embryo, Nonmammalian/abnormalities/*blood supply/embryology/metabolism ; Gene Deletion ; *Gene Expression Regulation, Developmental ; Hemorrhage/*embryology/genetics/metabolism ; Human Umbilical Vein Endothelial Cells ; Humans ; Intercellular Junctions/genetics/metabolism/ultrastructure ; Kinesin/genetics/metabolism ; Myosins/genetics/metabolism ; Zebrafish/*embryology/genetics ; p21-Activated Kinases/genetics/metabolism