title: Increased Salivary Nitrite and Nitrate Excretion in Rats with Cirrhosis.
abstract: Increased nitric oxide (NO) formation is mechanistically linked to pathophysiology of the extrahepatic complications of cirrhosis. NO is formed by either enzymatic or non-enzymatic pathways. Enzymatic production is catalyzed by NO synthase (NOS) while entero-salivary circulation of nitrate and nitrite is linked to non-enzymatic formation of NO under acidic pH in the stomach. There is no data on salivary excretion of nitrate and nitrite in cirrhosis. This study was aimed to investigate salivary levels of nitrate and nitrite in a rat model of biliary cirrhosis. Cirrhosis was induced by bile duct ligation (BDL). Four weeks after the operation, submandibular ducts of anesthetized BDL and control rats were cannulated with polyethylene microtube for saliva collection. Assessment of pH, nitrite and nitrate levels was performed in our research. We also investigated NOS expression by real time RT-PCR to estimate eNOS, nNOS and iNOS mRNA levels in the submandibular glands. Salivary pH was significantly lower in BDL rats in comparison to control animals. We also observed a statistically significant increase in salivary levels of nitrite as well as nitrate in BDL rats while there was no elevation in the mRNA expression of nNOS, eNOS, and iNOS in submandibular glands of cirrhotic groups. This indicates that an increased salivary level of nitrite/nitrate is less likely to be linked to increased enzymatic production of NO in the salivary epithelium. It appears that nitrate/nitrite can be transported from the blood stream by submandibular glands and excreted into saliva as entero-salivary circulation, and this mechanism may have been exaggerated during cirrhosis.
authors.affiliation: Department of Medical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Mahmoodi
authors.affiliation: Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Rahmatollahi
authors.affiliation: Department of Oral and Maxillofacial Pathology Dental Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Shahsavari
authors.affiliation: Department of Pharmacology and Toxicology, Pharmaceutical Sciences Branch and Pharmaceutical Sciences Research Center, Islamic Azad University, Tehran, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Shafaroodi
authors.affiliation: Department of Medical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Siyavash
authors.initials: S
authors.lastname: Grayesh-Nejad
authors.affiliation: Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. AND Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad R
authors.initials: AR
authors.lastname: Dehpour
mesh_terms: D000818:Animals; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008297:Male; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase
keywords: Cirrhosis; Nitrate; Nitric oxide; Nitrite; Rat; Saliva