George Kotani

Effect of a parenteral nucleoside-nucleotide mixture on hepatic metabolism in partially hepatectomized cirrhotic rats

After hepatectomy, purine and pyrimidine metabolism is a key process in synthesis of DNA and RNA and in energy metabolism. To supply nucleosides for salvage synthesis, nucleoside-nucleotide mixture solutions have been developed, and they have been found to improve protein metabolism and hepatic regeneration after partial hepatectomy in normal rats. However, the effect of the solution in cirrhotic liver, common in patients with hepatocellular carcinoma, has not been reported. The aim of this study was to evaluate the metabolic effect of the nucleoside-nucleotide mixture on cirrhotic rats after partial hepatectomy. Seventy percent partial hepatectomy was performed in thioacetamide-administered cirrhotic rats. The fractional protein synthetic rate, nitrogen balance, hepatic content of nucleic acid, and blood chemistry after the administration of the nucleoside-nucleotide mixture solution (OG-VI) with total parenteral nutrition was evaluated at 7 d after partial hepatectomy. OG-VI increased hepatic RNA level and hepatic fractional protein synthetic rate (p < 0.05). It is concluded that the nucleoside-nucleotide mixture solution is an effective nutritional supplement to the metabolism of cirrhotic rats after partial hepatectomy.

The Effect of Dietary Nucleic Acid Deficiency and the Administration of a Nucleotide and Nucleosides Mixture Solution on Endotoxin Shock in Rats

The importance of dietary nucleic acid in modulation of immune function without disease has been reported in nutritional disorder except under surgical stress. Dietary nucleic acid deficiency decreases T lymphocytes function1 and dietary ribonucleic acid (RNA) enhances immune response2. However, it is not known whether dietary nucleic acid influences on macrophage function. Recently, monocytes/macrophages are considered as key factors in the pathogenesis of systemic inflammatory response leading to septic shock by producing humoral mediators under endotoxin stimulation3, 4. Therefore, the aim of this study is to evaluate the influence of dietary nucleic acid deficiency on endotoxin shock and macrophage functions stimulated with lipopolysaccharide (LPS), which is the major component of endotoxin. Then, the effect of intraperitoneal administration of a nucleotide and nucleosides mixture solution (OG-VI)5 was evaluated.

A Nucleotide and Nucleosides Mixture Solution Improves Recovery of Energy Metabolism after Hepatic Ischemia in Rats

Hepatic ischemia/reperfusion is a common problem encountered under many clinical conditions, and it occurs in a variety of surgical procedures. Possible consequences include liver failure and/or multi-organ system failure, both of which have high rates of morbidity and mortality.1,2 Efforts to minimize the extent of injury incurred during the ischemic period or to maximize reparative process following ischemia have importance for survival.3 In vivo 31P-nuclear magnetic resonance (NMR) spectroscopy has been used to follow the response of hepatic high-energy phosphates during hepatic ischemia/reperfusion.4 It measures the continuous changes of hepatic adenosine triphosphate (ATP) levels and their metabolites, and is an effective tool to evaluate the serial data in the individual following drug treatment.

Utilization of purine and pyrimidine in human gastric cancer cells (KATO III): effect of a nucleotide and nucleosides mixture (OG-VI) solution on proliferation with coadministration of 5-fluorouracil.

Purine and pyrimidine are essential for cellular proliferation1, 2, 3. But, purine and pyrimidine are synthesized from glutamine in de novo synthesis pathway and cultured cancer cells do not require them in the medium. This is the reason that utilization of nucleosides by human cancer cells and their changes with 5 fluorouracil (5FU), the fluorinated analogue of uracil which is used in chemotherapy for various tumors2, 3, has not been reported. In this study, as a source of purine and pyrimidine, a solution containing a mixture of nucleosides and a nucleotide (OG-VI), developed recently as a nutritional supplement4, was used in the medium. It consists of purines, guanosine 5’-mono-phosphate (5’-GMP) and inosine, and pyrimidines, cytidine, uridine, and thymidine (TdR). It is known to increases hepatic regeneration and improve protein metabolism after partial hepatectomy in rats5, 6, and increase DNA synthesis in primary cultured hepatocytes7.