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C Oshio

Publications and source records attributed to C Oshio.

At least 37 records · Page 2Linked to original sources
PubMed1984

Taurocholate accelerates bile canalicular contractions in isolated rat hepatocytes.

The influence of sodium taurocholate on bile canalicular contractions was examined by time-lapse cinephotomicrography of isolated rat hepatocytes in primary monolayer cultures. Frame-by-frame analyses indicates that as the dose of taurocholate increased, the number of contractions increased in a dose-dependent manner up to 5 microM. Because bile canaliculi are the smallest biliary passages across which bile secretion occurs, and because it is known that taurocholic acid within the dose range used in these studies causes a linear increase in bile secretion, the results suggest that canalicular contractions may be a function of canalicular bile secretion.

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PubMed1983

Phalloidin alters bile canalicular contractility in primary monolayer cultures of rat liver.

We observed the motility of bile canaliculi in isolated rat hepatocytes obtained from animals that were pretreated with phalloidin (500 micrograms/kg body wt) for 1 and 3 days. Time-lapse cinephotomicrographs were taken in each experiment and in controls for 16.25 h. As we previously reported in normal hepatocytes, active contractions of bile canaliculi were observed. The number of contractions was 127.6 in controls, compared with 58.0 in 1-day phalloidin pretreated and 16.2 in 3-day phalloidin pretreated groups. The contraction process itself was not normal in the experimental groups, the contraction phase being slow and sustained. The altered canalicular motility depended on the dose of phalloidin administered. These results suggest that the integrity of actin filaments is necessary for normal bile canalicular motility. Further, dysfunction of actin microfilaments with altered canalicular motility may be involved in the pathogenesis of canalicular cholestasis.

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PubMed1983

Intrahepatic cholestasis as a canalicular motility disorder. Evidence using cytochalasin.

A rich network of actin-containing microfilaments are associated with the plasma membrane of the liver cells. These filaments are especially numerous in the pericanalicular region. Recently, active contractions of bile canaliculi have been observed in normal coupled isolated hepatocytes. In this report, we document that this motility behavior is abolished by cytochalasins B and D. Other cytoplasmic contractile movements are also reduced or lost after a brief initial period of enhanced surface activity with the formation of zeiotic blebs. The lack of contractile activity of bile canaliculi is accompanied by the gradual dilation of canalicular lumina. Since there is overwhelming evidence that the functional effects of the cytochalasins on cell motility are due to their effects on actin filaments, we propose that the altered canalicular contractility observed is due to the effects of cytochalasin on pericanalicular actin filaments. If bile canalicular contractility is a requirement for normal bile flow, then interference with this mechanism may be a factor in the pathogenesis of some types of intrahepatic cholestasis.

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PubMed1981

Contractility of bile canaliculi: implications for liver function.

Dynamic contractions of bile canaliculi were observed in groups of cultured hepatocytes by time-lapse cinephotomicrography during the early stages of monolayer formation. The contractions, which were forceful and appeared to have a pumping action, may facilitate the flow of bile in the liver's canalicular system.

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PubMed1979

Study on the fixation method of microcirculation system for electron microscopy.

1) Although glutaraldehyde solution was injected into the superior mesenteric artery, vessels and blood cells were not fixed immediately. 2) Glutaraldehyde was considered not to be suitable for the fixation of vessels and blood cells. 3) To observe the physiological and topographical correlation of vessels and blood contents, drop osmium fixation method was better to fix the microcirculatory units immediately. 4) The perfusion of glutaraldehyde was supposed to be necessary for the fixation of the solid tissue in which microcirculatory systems exist in deeper places like liver. However, the findings observed by the perfusion method might reflex microcirculatory disturbances occured by the perfusion of glutaraldehyde itself.

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PubMed1978

Budd-Chiari syndrome associated with protein-losing enteropathy.

Budd-Chiari syndrome associated with protein-losing enteropathy is reported. A 26-year-old male suffered from ascites, edema in the lower extremities, and engorgement of ascending veins on the abdominal wall. The diagnosis of Budd-Chiari syndrome was made by inferior vena cavography. The 131I-polyvinylpyrrolidone test showed the association of protein-losing enteropathy. The surgical operation was performed successfully, resulting in a marked improvement of signs and symptoms. To date, no similar case has yet been reported. There are, however, a number of reported cases of hypoproteinemia in Budd-Chiari syndrome, which might have been associated with a protein-losing enteropathy.

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PubMedDate not supplied

A study of bile canalicular contractions in isolated hepatocytes.

Living hepatocytes observed under standard methods of cell isolation and culture show frequent active contractions of bile canaliculi when viewed by time-lapse cinephotomicrography. This report gives details of the methods used to show the contractions. In addition, the characteristics of the contraction pattern are defined and analyzed. The contractions are regular, canalicular contraction time (systole) lasts 60 sec, and the most probably interval between contractions is 5 1/2 min. The finding of a regular pattern of contraction suggests an ordered, programmed, and integrated mechanism which entails a high degree of communication and functional coordination between neighboring hepatocytes.

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