Navegando por Palavras-chave "LIVER"

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    Is there a role for pericytic cells in the vascular bed of infantile hemangioendothelioma of the liver?
    (Editrice Compositori Bologna, 1991-01-01) Zerbini, Maria Cláudia Nogueira; Vianna, M. R.; Ribeiro, D.; Ayoub, AAR; Porta, Gilda; Sesso, Antonio; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Electron microscopic examination of an infantile hemangioendothelioma (IHE) type I of the liver, appearing in a five month old child, showed a high density of pericytes in the walls of the neoplastic vessels. These vessels, in part of the IHE patients, establish an important arteriovenous shunt leading to high output, congestive cardiac failure. It is unclear whether functions ascribed to pericytes, such as participation in microvascular contractility or as suppressors of endothelial cell proliferation are involved in two noteworthy aspects of the present case. The child exhibited no congestive heart failure and the multiple nodular lesions underwent spontaneous regression.
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    PLASMA KALLIKREIN and THROMBIN ARE CLEARED THROUGH UNRELATED HEPATIC PATHWAYS
    (Rapid Science Publishers, 1993-08-01) Loureirosilva, M. R.; Kouyoumdjian, M.; Borges, D. R.; Universidade Federal de São Paulo (UNIFESP)
    Plasma kallikrein (PK) and thrombin (TH), serine proteinases formed from inactive precursors, participate in important body defence mechanisms. the isolated hepatocyte recognizes TH, and the liver clears PK by calcium-independent receptors through mechanisms that are not yet clearly understood. It is known that heparin impairs the binding of TH to isolated liver cells through the inhibition of high affinity receptors. Using an isolated, exsanguinated and perfused rat liver preparation we confirmed that the TH hepatic clearance is calcium-independent and affected by heparin; PK clearance rates both in the presence (t1/2 10 +/- 2 min) or the absence (t1/2 10 +/- 1 min) of heparin were similar; the presence of beta-galactosides does not impair the TH clearance but adversely affects the PK clearance and a large excess of TH does not impair the PK clearance rate (t1/2 6 +/- 1 min). These results indicate that PK and TH are cleared by calcium-independent but otherwise unrelated hepatic pathways and suggest that TH may indeed facilitate the PK clearance by the liver.
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    PLASMA KALLIKREIN CLEARANCE BY the LIVER of CHRONIC CARBON TETRACHLORIDE-TREATED RATS
    (Blackwell Science Publ Austr, 1995-03-01) Toledo, C. F.; Kouyoumdjian, M.; Lanzoni, V. P.; Borges, D. R.; Universidade Federal de São Paulo (UNIFESP)
    We have previously reported that the endocytosis of rat plasma kallikrein (RPK) by hepatocytes is a calcium-independent and beta-galactoside-dependent mechanism. We now report the clearance of RPK by the liver of four groups of rats: normal, inflamed (48 h ex-turpentine) and two groups chronically treated with CCl4 (52 mg/kg per week, intragastrically, for 9-12 weeks). Each liver was isolated, exsanguinated and perfused at 37 degrees C with 30 mL of BSA-Krebs-Henseleit-bicarbonate medium containing 10 nmol/L RPK. Although all rats received the same mild CCl4 treatment, the liver histology showed that they evolved either to severe hepatitis (serum alanine aminotransferase [ALT] 4852 +/- 885 U/L, parenchymatous necrosis in the perivenous region) or to compensated cirrhosis (serum ALT 209 +/- 42 U/L, vigorous fibrous encircling regeneration nodules); neither jaundice nor ascites was noted. the results show that serum albumin was not altered among the groups and that: the acute-phase response by itself (inflamed group) increased RPK clearance rate (3.01 +/- 0.59 mL/min) as compared with the normal group (1.85 +/- 0.14 mL/min); the CCl4 treatment, although induced an acute-phase response, decreased (P < 0.01) RPK clearance rates (0.80 +/- 0.11 mL/min hepatitis group and 0.98 +/- 0.10 mL/min cirrhosis group). These findings suggest that the hepatic clearance rate of plasma kallikrein is an early indicator of liver injury.
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    PLASMA, KALLIKREIN CLEARANCE BY THE LIVER - A REVIEW
    (Assoc Bras Divulg Cientifica, 1994-08-01) Borges, Durval Rosa [UNIFESP]; Kouyoumdjian, Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    1. The liver is the main organ clearing both plasma and tissue kallikreins from the circulation. Hepatocytes are responsible for the internalization of rat plasma kallikrein (RPK) and the clearance of plasma kallikrein by the liver is Ca2+-independent. The binding site of RPK to the liver cell is located on its heavy chain which is not exposed on prokallikrein. An S-type lectin accounts for the receptor-mediated endocytosis of RPK.2. These properties of the liver are affected by pathological situations, particularly the acute-phase response to inflammation, in which the kallikrein-kinin system plays a major role. The hepatic clearance of the alpha(2)-macroglobulin-plasma kallikrein complex is less efficient than the clearance of the free enzyme.