Tatsuya Matsura

Acetaminophen-induced hepatic injury in mice: The role of lipid peroxidation and effects of pretreatment with coenzyme Q10 and α-tocopherol

This study was performed to determine whether oxidative stress contributed to the initiation or progression of hepatic injury produced by acetaminophen (APAP). Treatment of fasted mice with APAP (400 mg/kg, I.P.) led to hepatic injury as indicated by a marked elevation of plasma alanine aminotransferase (ALT). APAP caused an increased amount of thiobarbituric acid-reactive substance (TBARS), which was accompanied by a loss of reduced forms of coenzyme Q9 (CoQ9H2) and coenzyme Q10 (CoQ10H2) functioning as antioxidants. APAP also markedly decreased hepatic reduced glutathione (GSH) levels. Pretreatment with CoQ10 (5 mg/kg, I.V.) reduced hepatic TBARS levels to 30% and plasma ALT levels to 26% of placebo pretreatment levels without affecting hepatic GSH levels at 3 h of APAP treatment. alpha-Tocopherol (alpha-Toc) (20 mg/kg, I.V.) pretreatment also reduced hepatic TBARS levels to 13% and plasma ALT levels to 27% of placebo pretreatment levels without affecting hepatic GSH levels. These results suggest that oxidative stress followed by lipid peroxidation might play a role in the pathogenesis of APAP-induced hepatic injury, and pretreatment with lipid-soluble antioxidants such as CoQ10 and alpha-Toc can limit hepatic injury produced by APAP.

Changes in the content and intracellular distribution of coenzyme Q homologs in rabbit liver during growth

In order to determine whether coenzyme Q (CoQ) homologs which coexist in mammals play the same or different roles, the concentrations of coenzyme Q9 (CoQ9) and coenzyme Q10 (CoQ10) were analyzed in Japanese White (JW) rabbit tissues during growth, together with the intracellular distribution of these two CoQ homologs. In liver %CoQ9 (total [CoQ9] X 100/total [CoQ9] + total [CoQ10]) was approx. 40% until 3 weeks after birth, and then gradually decreased to 20%. In kidney, %CoQ9 decreased from 8% (1 week) to 1% (7 weeks). In heart, %CoQ9 was 3%, and in the brain, 2%, and these values did not change with growth. Most CoQ9 was present in the cytosolic fraction, whereas most CoQ10 was in the mitochondrial fraction. There was but minor change in the intracellular distribution of CoQ9 and CoQ10 in rabbit liver between 2 weeks and 7 weeks of age. These results suggest that CoQ9 and CoQ10 may play different roles in their physiological actions as antioxidant or component of the mitochondrial respiratory chain.

A Case of Gallbladder Perforation in Which the Developmental Pattern was Demonstrated by Laparoscopy

Abstract: A 58‐year‐old man with diabetes mellitus was referred to our clinic because of epigastric colicky pain of sudden onset with fever. An ultrasonography (US) and endoscopic ultrasonography (EUS) demonstrated marked thickening of the gallbladder wall and a pericholecystic echo‐free space. A laparoscopy showed tight adhesion between the greater omenturn and the parietal peritoneum, and pooling of bile on the liver surface, the greater omenturn, and in the perisplenic area. The gallbladder itself could not be seen. A surgical laparotomy revealed perforation of the gallbladder with a pericholecystic abscess. No laparoscopic observation of free bile has been reported in cases of gallbladder perforation.

Laparoscopic Observation of Hepatocellular Carcinoma with an Unusual Growth Pattern —Four Case Reports—

Abstract: Usually a laparoscopy is performed for many cases of hepatocellular carcinoma (HCC), but HCC with an unusual growth pattern is not encountered frequently. In this study we report on four cases of HCC which show an unusual growth pattern, who were found out of 96 cases of HCC examined by laparoscopy at our clinic. The first case of HCC considered occurred in a 72–year–old male with intraperitoneal dissemination; the second case, was discovered in a 71–year–old female, and had extrahepatic growth; the third case, in a 56–year–old male, ruptured spontaneously and produced an encapsulated hematoma; the fourth case, present in a 64–year–old male, also ruptured spontaneously. The clinico–pathological and laparoscopic features of HCC with an unusual growth pattern are discussed, placing emphasis on the value of laparoscopy in the diagnosis of HCC with an unusual growth pattern.