الفهرس | Only 14 pages are availabe for public view |
Abstract Nitric oxide is produced from Larginine by NOS enzymes. It performs a wide range of physiological functions as smooth muscle relaxation, apoptosis, memory and regulation of blood flow. Liver cirrhosis is a pathological condition characterized by a hyperdynamic circulation in which there is decreased vascular resistance and increased cardiac output. Systemic vasodilatation causes a decreased effective circulating blood volume which stimulates arterial baroreceptors leading to increased secretion of AVP, aldosterone and stimulation of sympathetic NS causing salt and water retention and ascites. NO is the stimulus for vasodilatation in cirrhosis. This study was carried out on 90 albino rats which were divided into 2 groups :normal rats (10 rats ) and cirrhotic rats (80 rats ). 60 cirrhotic rats were given Larginine or LNAME before, during or after induction of cirrhosis,while 10rats wre used as a control. At the end of the study ,24 hour urine was collected for determination of urine vilume, urine osmolarity and concentrations of Na, K and creatinine. Also, blood samples were collected to measure the concentrations of Na, K, creatinine, bilirubin, AST, ALT, albumin, aldosterone, AVP, renin, norepinephrine and osmolarity. It was found that Larginine has a marked protective effect on the liver in cirrhosis particularly if administered early in the disease. LNAME increases salt and water excretion but it also increases hepatic resistance and worsens liver pathophysiology , so caution is raised about its use in cirrhosis. |