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Biomedical subjects

K Momose

Publications and source records attributed to K Momose.

At least 145 records · Page 8Linked to original sources
PubMed1985

Stimulatory effect of calcitonin on fatty acid synthesis in the liver of fed rats.

The effect of calcitonin (CT) on free fatty acid concentration in the serum and liver of fed rats was investigated. A single subcutaneous administration of CT (synthetic [Asu1,7] eel CT;80 MRC mu/100 g body weight) produced a significant increase in serum free fatty acid concentration. An appreciable effect of CT was observed at a dose of 5 MRC mU/100 g body weight. The hormonal effect was also observed in thyroparathyroidectomized rats. The effect of CT on serum free fatty acid was diminished by fasting. Free fatty acid content in the hepatic cytosol of fed rats was markedly increased by CT administration. The hormonal effect was observed at a dose of 5 MRC mU/100 g body weight. Furthermore, stimulation of fatty acid synthesis caused by intraperitoneal injection of alanine (1.122 mmoles/100 g body weight) was markedly enhanced by administration of CT (5, 20 and 80 MRC mU/100 g body weight). This effect of CT on the liver may be the cause of increased level of fatty acid in the serum. The present results suggest that CT may stimulate synthesis of free fatty acid in the liver of fed rats.

Alanine↗
PubMed1984

The role of serotonin in mucociliary transport system in the ciliated epithelium of frog palatine mucosa.

The effects of serotonin (5-hydroxytryptamine, 5-HT) on mucociliary transport and mucus secretion were investigated pharmacologically. The presence of 5-HT in the ciliated epithelium of frog palatine mucosa was examined chromatographically. Mucociliary transport was accelerated by the application of 10(-6) M 5-HT. Mucus secretion was also stimulated significantly by 5-HT (30 mg/kg). 5-HT in the mucosa was detected by a chromatographic technique when a large amount of 5-HT precursor, 5-hydroxytryptophan (5-HTP), was given previously. Phenylhydrazine was used as MAO inhibitor. When phenylhydrazine (20 mg/kg) was given before 5-HTP, 5-HT was markedly concentrated in the mucosa. Radioactive 5-HT was also detected in the mucosa after incubation with [14C]5-HTP. One hour after systemic administration of [3H]5-HTP, a large number of silver grains appeared in the autoradiograms of some epithelial cells. These results suggest the possibility that epithelial cells with the ability to synthesize 5-HT from 5-HTP exist in ciliated epithelium. A possible functional relationship is proposed between the regulation of mucociliary transport with mucus secretion and 5-HT-containing cells.

5-Hydroxytryptophan↗
PubMed1984

Calcitonin increases alanine aminotransferase activity related to calcium in the hepatic mitochondria of rats.

The effect of calcitonin (CT) on alanine aminotransferase activity and calcium content in the hepatic mitochondria of intact rats was investigated. A single subcutaneous administration of CT (synthetic [Asu1,7] eel calcitonin; 80 MRC mU/100 g body weight) produced a significant increase in alanine aminotransferase activity and a corresponding elevation of calcium content. Those increases were also observed with the lowest dose of CT (20 MRC mU/100 g). The mitochondrial calcium depletion by 10 mM EGTA treatment produced a remarkable reduction in alanine aminotransferase activity increased by CT, although EGTA treatment did not alter basal enzyme activity. Addition of calcium ion (1-10(3) microM) into the EGTA-treated mitochondria, however, produced a significant increase in alanine aminotransferase activity. The enzyme activity increased by CT was not inhibited by the presence of calmodulin inhibitor, W-7 (1-10(3) microM). These results suggest that the mitochondrial calcium increased by CT administration directly activates alanine aminotransferase in the hepatic mitochondria of rats.

Alanine Transaminase↗
PubMed1984

Effect of calcitonin on fructose 1,6-diphosphatase activity in rat liver: role of cytosolic calcium concentration.

The effect of calcitonin (CT) on fructose 1,6-diphosphatase activity in the hepatic cytosol was investigated after a single subcutaneous administration of the hormone to rats. Administration of CT (synthetic [Asu1,7] eel CT; 80 MRC mU/100 g body weight) produced significant increase in fructose 1,6-diphosphatase activity and calcium content in the hepatic cytosol of intact and thyroparathyroidectomized rats. Those alterations were also observed with the dose of CT at physiological level. The binding of calcium by 10 microM EGTA in the hepatic cytosol caused a clear reduction of the increase in fructose 1,6-diphosphatase activity produced by CT administration. The enzyme activity of CT-treated rats was markedly reduced by W-7 (100 microM), calmodulin inhibitor, while that of control rats was not significantly altered by the drug. Meanwhile, fructose 1,6-diphosphatase activity in the hepatic cytosol obtained from normal rats was significantly enhanced by addition of calcium ion (0.1-5.0 microM). This increase was also clearly inhibited by W-7. These results suggest that CT increases fructose 1,6-diphosphatase activity in the hepatic cytosol of rats, and that this hormonal regulation may depend on calmodulin, mediated through calcium increased in the cytosol.

Animals↗
PubMed1984

[Nutritional support in surgery: with special reference to fat emulsion and carnitine].

Energy metabolism of fat emulsion has been studied in rats with various conditions including postoperative catabolism, chronic and acute hepatic dysfunction, diabetes and sepsis. The results indicate that fat emulsion is rapidly eliminated from the blood stream and metabolized readily even in such conditions. Based on these findings, we have actively employed fat emulsion clinically as energy source. In septic rats, it was demonstrated that levels of carnitine decreased and that this decrease was based upon a decrease of synthesis. When carnitine was administrated together with fat emulsion, the energy metabolism returned to approximately normal level. This report also describes the tissue concentrations of carnitine in diabetic rats and the blood and urine concentrations of carnitine in postoperative patients.

Animals↗
PubMed1984

[A case of highly atypical hyperplasia--difficult to differentiate from carcinoma].

We present a 51-year-old nulliparous woman with highly atypical hyperplasia of the uterus induced by the prolonged use of exogenous estrogen. The patient was given nearly 1,415 mg of estradiol dipropionate intramuscularly for over 23 years after operation for bilateral ovarian cysts. She complained of vaginal bleeding and diagnostic endometrial curettage revealed highly atypical hyperplasia which was difficult to differentiate from well differentiated adenocarcinoma. On hysterectomy, atypical tissues were limited to the upper part of the posterior wall of the uterus with no muscle invasion.

Adenocarcinoma↗
PubMed1983

Studies on isolated smooth muscle cells. VIII. 45Ca-efflux from single smooth muscle cells isolated from taenia coli of guinea pig.

45Ca-loaded single smooth muscle cells were prepared from taenia coli of guinea pig. The cells were perfused continuously with physiological salt solution on membrane filter with pore size of 12 microns and radioactivity in the effluent was determined. The 45Ca-efflux curves consisted of two straight lines in semilogarithmic figure representing loosely and tightly bound calcium compartments with half time of 1.87 +/- 0.27 and 6.78 +/- 0.43 min, respectively. The loosely bound calcium was supposed to be localized on plasma membrane. Size of the tightly bound 45Ca was dependent on period for calcium-depletion of the preparation prior to 45Ca-loading. The efflux was stimulated by acetylcholine and the stimulated efflux returned to the spontaneous efflux level instantly after removal of acetylcholine. This stimulation was abolished by atropine. Repetitive stimulation failed to increase 45Ca-efflux while the rate of the spontaneous 45Ca-efflux did not change significantly. These results suggested that, in taenia coli of guinea pig, at least three calcium compartments existed, loosely bound calcium, tightly bound calcium and more tightly bound calcium which can be released by acetylcholine, in addition to calcium in extracellular fluid. Advantages and disadvantages of using single smooth muscle cells for investigation of calcium movement and some technical improvement for determination of 45Ca-efflux from single cells were described.

Acetylcholine↗
PubMed1983

Calcitonin increases calcium content and glucose-6-phosphatase activity in hepatic microsomes of rats.

The effect of calcitonin (CT) on calcium content and glucose-6-phosphatase activity in the hepatic microsomes of rats was investigated. A single sc administration of CT (80 MRC mU/100 g body weight) produced a significant increase in microsomal calcium content and a corresponding elevation of microsomal glucose-6-phosphatase activity. An appreciable effect of CT was observed at a dose of 20 MRC mU/100 g body weight. On the other hand, the removal of calcium by 10 mM EGTA washing of the microsomes caused a marked reduction of glucose-6-phosphatase activity raised by CT administration. The addition of calcium ion at the amount of 10(-2)-10(3) nmoles Ca2+ per mg protein in the microsomes produced a significant increase in glucose-6-phosphatase activity. The present results suggest that microsomal calcium increased by CT administration activates glucose-6-phosphatase in the hepatic microsomes of rats.

Animals↗
PubMed1983

Calmodulin dependency of calcitonin action on glucose-6-phosphatase and phosphorylase alpha activities in the liver of rats.

The calmodulin dependency of calcitonin (CT) action on glucose-6-phosphatase and phosphyorylase alpha activities in the liver of rats was investigated. A single sc administration of CT (synthetic [A1,7] eel CT; 80 MRC mU/100 g body weight) produced significant increases in calcium content and glucose-6-phosphatase activity in the hepatic microsomes of intact and thyroparathyroidectomized rats. These increases in enzyme activity were significantly inhibited by W-7 (100 microM), with a concentration which showed maximal effect. However, this inhibition was less than 50% of the enzyme activity increased by CT administration. Meanwhile, CT produced significant increases in calcium content and phosphorylase alpha activity in the hepatic glycogen particles from intact rats. However, this increase in enzyme activity was not influenced significantly by W-7 (100 microM), suggesting that the calcium ion may directly activate the enzyme. These results suggest that the increase in microsomal glucose-6-phosphatase activity of rat liver mediated by cellular calcium following CT administration may partly depend on calmodulin.

Animals↗
PubMed1982

Calcitonin increases calcium content and phosphorylase a activity in the hepatic particulate glycogen of rats.

The effect of calcitonin (CT) on hepatic glycogenolysis was investigated after a single subcutaneous administration of the hormone to intact rats. Administration of CT (porcine CT; 80 MRC mU/100 g BW) produced a significant decrease in glycogen content of the liver, and corresponding increases in phosphorylase a activity and calcium content of the particulate glycogen fraction in the liver. These alterations were observed with the dose of CT at physiological level. The removal of calcium by 1 mM EGTA treatment of the hepatic particulate glycogen caused a clear reduction in the increase in phosphorylase a activity produced by CT administration. Meanwhile, the enzyme activity in 1 mM EGTA-treated particulate glycogen of the liver in both control and CT (80 MRC mU/100 g BW)-treated rats was significantly enhanced by the addition of calcium ion (10 microM). Furthermore, a single intraperitoneal administration of calcium chloride (2.0 mg Ca/100 g BW) to intact rats produced a remarkable increase in phosphorylase a activity and calcium content of the hepatic glycogen particulate fraction. These results suggest that the promotion of hepatic glycogenolysis by CT administration may result from the increase in phosphorylase a activity mediated by cellular calcium.

Animals↗
PubMed1981

Studies on isolated smooth muscle cells. VII. Response to agonists and the contraction velocity of taenia coli of guinea pig and the single smooth muscle cells.

Single smooth muscle cells were isolated from taenia coli of guinea pigs and degrees of responses of acetylcholine, histamine and prostaglandin E2, and velocity of acetylcholine-contraction were compared with those of whole tissue. The contraction of single cells by these agonists were dose-dependent and ED50 of acetylcholine, histamine and prostaglandin E2 were 0.3 - 1.1 x 10(-6), 5-11 x 10(-7) and 1-3 x 10(-9) M, respectively. These values were quite similar to those obtained with whole tissue. It took 2.0 +/- 0.2 s for the single cells to be contracted completely by 10(-4) M acetylcholine while it took 6.9 +/- 0.2 s for the isotonic contraction of whole tissue. Times for a half maximum contraction, assuming that the whole tissue and the single cells were contracted at the maximum velocity, were 1.43 +/- 0.05 and 0.92 +/- 0.12 s, respectively when 10(-4) M acetylcholine was applied. These results revealed the response of muscle cells in the tissue to agonists was reflected on magnitude of the contraction of whole tissue and suggested that pharmacological properties of smooth muscle cells of taenia coli were not changed during the isolation procedure, whereas velocity of contraction of single cells was faster than that of whole tissue. Reasons for the difference in velocity were discussed.

Acetylcholine↗
PubMed1980

[Studies on isolated smooth muscle cells. VI. Dispersion procedures for acetylcholine-sensitive smooth muscle cells of guinea pig (author's transl)].

Dispersion procedure of smooth muscle cells from collagenase-treated minces of guinea pig taenia coli and their response to acetylcholine were examined in order to apply the single smooth muscle cells to investigation of contraction mechanisms of smooth muscle. Pipetting the mince suspension was convenient procedure for the dispersion of single cells. For good yield of acetylcholine-sensitive cells, very mild pipetting was required although yield of single cells was lower. Under the condition, 10(3)-10(4) cells were obtained from 3-4 cm of taenia coli strip and about a half of the cells were responsive to acetylcholine. The cells became 40% of the original length by administration of 10 mM acetylcholine. Once the cells were dispersed and suspended in the physiological salt solution the cells lost the sensitivity to acetylcholine within 90 minutes while very mild pipetting of the mince suspension provided acetylcholine-sensitive cells over 3 hours. These single cells were applicable to investigation of contraction mechanisms of smooth muscle in addition to whole tissue as used so far. It was also suggested in the experiment that acetylcholine-sensitive site of cells might be damaged by exposure to physiological salt solution while it was well preserved in the tissue even though the tissue was digested by collagenase.

Acetylcholine↗