Pulmonary abnormalities are common in patients with advanced chronic liver disease. Two distinct syndromes strictly related to the presence of portal hypertension, but clearly different from a pathophysiologic point of view, have been identified. Portopulmonary hypertension, characterized by an increased pulmonary arterial pressure, is due to a progressive arteriolar vasoconstriction induced by...

BACKGROUND Medullary blood flow is via vasa recta capillaries, which possess contractile pericytes. In vitro studies using isolated descending vasa recta show that pericytes can constrict/dilate descending vasa recta when vasoactive substances are present. We describe a live kidney slice model in which pericyte-mediated vasa recta constriction/dilation can be visualized in situ. METHODS Confo...

Carcinoid tumors are relatively rare neuroendocrine malignancies most commonly originating from enterochromaffin cells in the gastrointestinal tract. The incidence is 1 in 100 000 of the general population.1 They usually grow slowly over years, commonly causing no symptoms at all until they become large or have metastasized. Carcinoid tumors of midgut origin may secrete large amounts of vasoact...

The myocardial reperfusion following ischemia leads to the ischemic vasodilation by affecting the release of various vasoactive substances, such as free radicals, NO, and histamine. In addition, some evidences suggest that glucagon itself may alter the release of those substances. In this study, we investigated the ischemic vasodilation of the isolated rat heart, as well as the concentrations o...

We examined the association between severity of disease in mastocytosis and skeletal manifestation and bone markers in 16 patients varying in extent of mastocytosis as determined by the urine excretion of methylimidazoleacetic acid. Both osteoporosis and osteosclerosis were found. Bone density in the hip was significantly higher (p < 0.05) in both men and women with an enhanced histamine metabo...

The literature indicates that vasoactive substances released from platelets contribute to the pulmonary pressor response and hypoxemia during pulmonary microembolism. Hence, removal of the platelets or inhibition of their function should reduce these effects. The purpose of this study was, therefore, to investigate the pulmonary effects of experimental embolism with glass beads in dogs rendered...

Vascular endothelial cells play an important role in modulating cardiovascular function, by liberating several vasoactive substances, such as prostacyclin, endothelium-derived relaxing factor/nitric oxide, a hyperpolarizing substance, and vasoconstrictor substances. Their roles in the cardiovascular system include modulation of the contraction of the underlying vascular smooth muscle, interacti...

Endothelial cells synthesize and release vasoactive mediators in response to various neurohumoural substances (e.g. bradykinin or acetylcholine) and physical stimuli (e.g. cyclic stretch or fluid shear stress). The best-characterized endothelium-derived relaxing factors are nitric oxide and prostacyclin. However, an additional relaxant pathway associated with smooth muscle hyperpolarization als...

The corpus luteum (CL) undergoes drastic changes in its function and structure during the estrous cycle. To secrete a sufficient amount of progesterone (P4) to ensure the occurrence of pregnancy in a cow with a body weight greater than 500 kg, the bovine CL weighs 5-8 g which is 2-3 thousand times heavier than rat CL. If pregnancy does not occur successfully, rapid luteolysis is caused by prost...