Biomedical subjects

N Ohkohchi

Publications and source records attributed to N Ohkohchi.

At least 109 records · Page 6Linked to original sources

PubMed1985

[Application of a potential difference to evaluate the absorptive faculty in the small intestine. The changes in potential differences, uptake of sugars and amino acid and electrical transmural resistance in injured intestine].

Since there was no effective method for evaluating the absorptive capacity in the small intestine, we devised a test for evaluating the absorptive capacity with potential difference. Potential difference is provided by electrical resistance of intestine and flux of substances. Previously, we reported that the electrical resistance of the small intestine in the guinea pigs had changed very slightly throughout the entire life, and that sugars and neutral amino acids have been transported completely activity from the birth. In addition, potential difference of glycyl-glycine reflected the uptake of the intestine after the period of weanling. We experimentally studied the electrical transmural resistance and absorptive capacity of the small intestine with various damages to the small intestine by 5-Fu, ischemia and long fasting. Histologically, swelling of nucleus, intracellular edema, dilatation of capillary vein, dropping of epithelial cells, etc., were seen in these models. But the electrical resistance was slightly changed in 10% of the cases. Potential differences by sugars or neutral amino acid ingestion accurately reflected their real flux. These facts suggest that the potential differences deficiently reflect the uptake of sugars and amino acids in the small intestine under conditions with malabsorption.

Amino Acids↗

PubMed1984

Species difference in mechanisms of D-xylose absorption by the small intestine.

Comparisons were made for the ability of D-xylose to evoke changes in the transepithelial potential difference upon its addition to the mucosal solution between guinea pig and rat small intestines. Also, Na+-dependence of D-xylose influx from the mucosal solution into epithelial cells, and the phlorizin-sensitivity of the influx, were compared between these animals. In guinea pig intestine, the sugar caused an immediate and sustained increase in the transmural potential difference, and this potential increment was completely abolished by phlorizin. In contrast, the sugar did not cause any electrical changes in the rat small intestine. The influx of D-xylose across the mucosal border was Na+-dependent and phlorizin-sensitive in guinea pigs, while it was Na+-independent and phlorizin-insensitive in rats. The results indicate that there is a qualitative difference in the mode of transport of D-xylose between guinea pigs and rats.

Absorption↗

PubMedDate not supplied

Excessive portal flow causes graft nonfunction in small size liver transplantation: an experimental study in pigs.

We investigated the effects of portocaval shunt (PCS) on excessive portal flow in producing sinusoidal microcirculatory injury in small-for-size liver transplants in pigs. The posterior segment of a whole liver (25%) was transplanted orthotopically. The pigs were divided two groups: group A, graft with PCS (n = 11), and group B, graft without PCS (n = 11). The PCS was a side-to-side anastomosis of the portal vein and the inferior vena cava. In group A, eight pigs survived for more than 4 days; all pigs except for one died of graft nonfunction within 24 hours in group B. The portal flow after reperfusion decreased in group A, but increased about three times greater in group B than that before the operation (P < .01). In group B, destruction of the sinusoidal lining and bleeding in the periportal areas were observed after reperfusion, findings that were not recognized in group A. These results suggest that graft nonfunction after small-for-size liver transplantation may be attributable to excessive portal flow producing sinusoidal microcirculatory injury.

Animals↗

PubMedDate not supplied

Backtransplantation for survival of the graft.

To assess survival of grafts after uncontrollable rejection, one performs backtransplantation from the recipient to the donor. This study investigated backtransplantation in an animal model. Hearts were transplanted heterotopically in rats. After a few days, the transplanted heart grafts were harvested from the recipients and backtransplanted to the donor strain heterotopically and a drug was administered. Cardiac grafts survived 6.2 days in the first recipients. After backtransplantation on day 5 or 6, all backtransplanted grafts survived well in the second recipients. After backtransplantation on day 7, when 4 of 5 grafts had no beat, 2 of 5 grafts recovered beating on day 3 after backtransplantation without any drug treatment. After backtransplantation on day 7, when 4 of 5 grafts had no beat, all (5 of 5 grafts) recovered beating well with the administration of FTY720 on day 3 after backtransplantation. CsA or FK506 had no effect on survival after backtransplantation. Pathological findings revealed mild cellular infiltration in the cases of FTY720 and severe necrosis in the cases of no drug, CsA, or FK506. After backtransplantation on day 8, no grafts (0 of 5 grafts in each drug) recovered beating with any drugs. These data document the possibility of backtransplantation.

Animals↗

PubMedDate not supplied