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Biomedical subjects

M Minato

Publications and source records attributed to M Minato.

47 records · Page 3Linked to original sources
PubMed1986

Effects of intravenous administration of a calcium antagonist on prostaglandins and thromboxane in plasma and urine in humans.

The effects of a calcium antagonist [Nicardipine hydrochloride (NH)] on the prostaglandin [prostaglandin E2 (PGE2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha)] and thromboxane B2 levels in the blood and urine were examined in 6 patients with essential hypertension following intravenous infusion of NH for 120 minutes. At the same time, the plasma renin activity (PRA), plasma aldosterone concentration (PAC), and plasma and urinary electrolyte levels were also determined. During NH administration, the blood pressure was significantly decreased (p less than 0.05) with an increased pulse rate (p less than 0.05). PRA was significantly increased after NH loading (p less than 0.05) but PAC showed no change. The plasma PGE2 and 6-keto-PGF1 alpha levels tended to increase slightly, while the blood thromboxane B2 level showed a decreasing tendency. The 6-keto-PGF1 alpha to thromboxane B2 ratio was significantly increased after NH loading as compared to the preloading ratio (p less than 0.05), and then returned to the preloading value at about 30 minutes after discontinuation of NH loading. The urinary excretions of PGE2, 6-keto-PGF1 alpha and thromboxane B2, PGE2 and 6-keto-PGF1 alpha tended to decrease after NH loading. In particular, the decrease in PGE2 was statistically significant (p less than 0.05). No change occurred in the urinary excretion of thromboxane B2. The above findings indicate that NH increased the plasma 6-keto-PGF1 alpha to thromboxane B2 ratio but decreased the urinary excretion of prostaglandins. In addition, the possible involvement of an enhanced 6-keto-PGF1 alpha/thromboxane B2 ratio in part of the hypotensive mechanism of NH is suggested.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Therapeutic efficacy of the transplantation of isolated hepatocytes in rats with surgically induced acute hepatic failure: a study of the mechanism.

In this study, the beneficial effect of intrasplenic transplantation of hepatocytes or splenocytes was shown in animals with 75% hepatectomy and portacaval shunt but not in animals with total dehepatization by hepatic vascular exclusion. No enhancement of the phagocytic activity was observed in the animals with 75% hepatectomy and portacaval shunt after injection of hepatocytes or splenocytes. This study confirms the efficacy of hepatocytes for the treatment of experimental liver failure but shows that nonhepatic cells may be equally as effective. Metabolic activity of the transplanted cells and stimulation of the phagocytic activity of the reticuloendothelial system probably do not explain the therapeutic effect of the transplanted cells.

Animals↗
PubMed1986

An in situ experimental model in rabbits for the study of rectal absorption.

An in situ experimental model of rectal absorption was studied in rabbits compared with in vivo determination of drug concentration in the plasma of postcaval vein using indomethacin as drug. Pharmacokinetic parameters were similar between in vivo and in situ. When results from both studies were compared, 60% of the drug administered to the rectum was absorbed from the superior hemorrhoidal vein and the remaining 40% was absorbed from the inferior hemorrhoidal vein. When an aspirin suppository was used in this model, the amount of unaltered aspirin absorbed in the rectal mucosa or space was greater than the absorbed salicylic acid which was metabolized or degradated from aspirin. In the case of insulin, these differences were not seen in the insulin concentration of venous plasma between insulin physiological saline and surfactant suspension. However, using the in situ model, the surfactant effect on rectal absorption of insulin was observed. From the above results, it was concluded that this in situ experimental model of rectal absorption has advantages in that it can be used directly to measure the rectal absorption rate and to determine ratios of easily metabolized and poorly absorbed drugs. Therefore, this model appears to be useful in evaluation of rectal absorption.

Animals↗
PubMed1984

Transplantation of hepatocytes for treatment of surgically induced acute hepatic failure in the rat.

Efficacy of transplanted hepatocytes was evaluated in rats with a surgically induced acute hepatic failure. After 75% liver resection and portacaval shunt, the intrasplenic or intraperitoneal injection of 20 million isolated fresh hepatocytes was shown to significantly reduce the mortality rate. These results confirm that the transplantation of isolated hepatocytes may prevent death in rats with acute hepatic failure, and suggest that hepatocyte transplantation acts by a mechanism of hepatic support.

Acute Disease↗
PubMed1982

Surgically induced acute hepatic failure in the rat.

Several surgical procedures were tested in the rat in order to create a spontaneously lethal but potentially reversible acute hepatic failure. Two combined surgical procedures fulfill these conditions: '75% hepatectomy' plus portacaval shunt and '85% hepatectomy' plus 30-min clamping of the celiac and superior mesenteric arteries. These two procedures should constitute useful tools for the evaluation of new methods of hepatic support.

Animals↗
PubMed1981

Maintenance of rat liver viability enhanced by cold flushing with oxygenated perfluorochemicals.

The possible benefit of oxygenation during initial cold flushing was investigated as means of improving the quality of live preservation in rats. In five group of animals (total 61 experiments), the lives were flushed with different perfusates. Non-oxygenated groups included controls, Collins' solution alone and Collins' solution containing perfluorotributylamine (FC-43). In the oxygenated groups, Collins' solution alone and collins' solution containing FC-43 were oxygenated by bubbling. The hepatic ATP level and histopathological changes were used to assess the quality of liver preservation. Oxygenation during the initial cooling process proved to be effective in maintaining energy metabolism and preventing the characteristic microscopic changes of ischemic damage. Oxygenated Collins' solution containing FC-43 showed a much longer lasting effect compared with oxygenated Collins' solution alone. Without FC-43. Under light microscopy, in integrity of the liver appeared to be well preserved up to eight hours with the former solution. It is concluded that enhanced oxygenation with FC-43 in the initial cold flushing period can improve the quality of liver preservation.

Adenosine Triphosphate↗
PubMedDate not supplied

Trace elements and mineral requirements for very low birth weight infants in rickets of prematurity.

To establish mineral and trace element requirements for very low birth it is important to prevent bone mineral disorder. Those infants fed mother's milk only are thought to be at higher risk of this disorder. Both calcium and phosphorus supplementation were thought to be needed to prevent it. Copper and zinc are important as cofactors of major enzymes involved in the synthesis of collagen. These trace elements especially zinc may not be enough for very low birth weight infants fed mother's milk. At present however the relationship between these trace elements and minerals, and bone metabolic disease in preterm infants is not completely clear.

Humans↗