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Biomedical subjects

K Momose

Publications and source records attributed to K Momose.

At least 127 records · Page 7Linked to original sources
PubMed1990

Minimal and mild endometriosis. Nd:YAG laser treatment and changes in prostaglandin concentrations in peritoneal fluid.

Among many patients, infertility originates with minimal and mild endometriosis. Recently, peritoneal fluid factors have come to be associated with infertility in minimal and mild endometriosis patients, and prostaglandin (PG) is suspected of being one of those factors. We use the Nd:YAG laser for treatment of endometriosis; a total of 52 cases of minimal and mild endometriosis have been treated so far with the laser under laparoscopy in our clinic. At the same time we measured the peritoneal fluid volume and PG concentration in peritoneal fluid. Peritoneal fluid volume and PGE2 concentrations were found to be significantly higher than those in the control group (tubal obstruction patients). Seven of 52 patients received second-look laparoscopy three months after Nd:YAG laser treatment; the PG concentration showed a tendency to decrease in many patients, and the PGE2 concentration turned out to be insignificant. Within one year, 30 patients achieved pregnancy. In minimal and mild endometriosis patients Nd:YAG laser treatment may alter the PG concentration in peritoneal fluid, thereby increasing the change of pregnancy.

Ascitic Fluid↗
PubMed1990

Phosphatidic acid-induced contraction in guinea-pig taenia coli.

Natural phosphatidic acid from egg yolk lecithin (PA) caused a sustained contraction in guinea-pig taenia coli. The contractile response to PA was concentration-dependent (10(-6)-10(-4) M) in the normal medium and the maximal response to PA was about 20% of the response to carbachol (CCh) at 10(-6) M. Phospholipase D mimicked PA-induced contraction. This result suggests that increase in endogenous PA can induce contraction. The PA-induced contraction was not inhibited by atropine (10(-6) M). The contraction was more dependent on concentration of extracellular Ca2+ than CCh-induced contraction. PA increased 45Ca2+ uptake into the tissue. These results suggest that the PA-induced contraction results from increase in Ca2+ influx across plasma membranes, but not release of Ca2+ from intracellular stores in guinea-pig taenia coli. The PA-induced contraction was inhibited to 42% of the control response by propyl gallate (0.2 mM), a combined inhibitor of cyclooxygenase and lipoxygenase. This result indicates that a portion of the contraction is related to release of arachidonic acid and its metabolites, and the other portions are based on direct action of PA. These results suggest a possibility that increased PA by agonist stimulation is related to the following extracellular Ca2(+)-dependent contraction.

Animals↗
PubMed1989

Identification of regulatory sites in the biosynthesis of ubiquinone in the perfused rat heart.

The biosynthesis of ubiquinone was studied in an isolated perfused beating heart preparation from adult male rats to determine rate-limiting steps in the biosynthetic pathway. The isolated heart could incorporate p-hydroxy[U-14C]benzoate into ubiquinones (ubiquinone-9 and -10) and two other lipids which were identified as 3-nonaprenyl 4-hydroxybenzoate and 3-decaprenyl 4-hydroxybenzoate. No other lipids could be detected. Addition of unlabeled mevalonolactone to the perfusate stimulated the rate of incorporation of p-hydroxy[U-14C]benzoate into 3-nonaprenyl 4-hydroxybenzoate and 3-decaprenyl 4-hydroxybenzoate. The level of radioactivity in these intermediates was much greater than that in ubiquinone-9 and -10. These results show that in the intact heart there is a large excess capacity to form postmevalonate isoprenoid precursors of ubiquinone and suggest a possible regulatory step at the premevalonate level. Moreover, the accumulation of prenylated derivatives of 4-hydroxybenzoic acid indicates further rate limitation at one or more of the subsequent steps in conversion of these intermediates to ubiquinone.

Animals↗
PubMed1989

Loading of fura-2/AM with an aid of DFP on single smooth muscle cells prepared from guinea pig taenia coli.

Procedures for loading fura 2 acetoxymethyl ester (fura 2/AM) into smooth muscle cells isolated from guinea pig taenia coli have been investigated. It was difficult to load these cells with fura 2 in the absence of diisopropylfluorophosphate (DFP). The presence of DFP, a potent cholinesterase (ChE) inhibitor during the loading, significantly enhanced the incorporation of the fura 2 into the cells. More than 80% of the single cells treated with DFP and fura 2/AM were viable. DFP did not affect the ability of the cell to shorten in response to either Ca2+ or carbachol (CCh). The single cells contracted transiently with caffeine and the intracellular Ca2+ concentration increased simultaneously. The results indicate that the amount of fura 2/AM incorporated into the single smooth muscle cells depends on the activity of ChE or various serine proteases located outside the cells and suppression of these enzymes induces more efficient incorporation, which permits shorter incorporation periods. Since the presence of DFP may shorten the incubation time significantly, the viability of these cells is improved. The procedure might be applicable for measuring simultaneously the contraction of cells and the behavior of intracellular Ca2+ in the same cells.

Animals↗
PubMed1989

Effects of pluronic F-127 on loading of fura 2/AM into single smooth muscle cells isolated from guinea pig taenia coli.

The effect of Pluronic F-127 (PF-127), a surfactant polyol, on the loading of fura 2/AM into smooth muscle cells isolated from guinea pig taenia coli was investigated. The presence of PF-127 during the loading of fura 2 acetoxymethyl ester (fura 2/AM), an intracellular Ca indicator, occasionally increased the incorporation of the dye into the cells. However, long time loading (over approximately 60 min) in the presence of PF-127 decreased the incorporation of fura 2. When the extracellular medium obtained from cells treated with DFP, then incubated with fura 2/AM in the presence of PF-127 was analyzed with excitation spectra, the fluorescence peaks shifted to longer wave lengths by addition of EGTA. However, the peak of the extracellular medium obtained from cells treated with DFP, then incubated without PF-127, did not shift. These results show that PF-127 affects the membranous permeability of the dye in single smooth muscle cells, permitting fura 2 hydrolyzed in the cytoplasm to leak out through the membrane.

Animals↗
PubMed1988

Improvement of a procedure for preparing single smooth muscle cells from guinea pig tenia coli by purified collagenase and papain.

Procedures for isolating single smooth muscle cells from tenia coli of guinea pigs have been developed. The cells were isolated with a combination of highly purified collagenase and a small amount of strong peptidase, papain, in the presence of Ca. This combination resulted in approximately a 100-fold yield of the single cells as compared with the ordinary method in which only collagenase preparations contaminated with various peptidases were used. More than 95% of the single cells were viable when examined by the trypan blue exclusion technique. In addition, this combination greatly increased the responsiveness to agonists such as carbachol (CCh). A concentration of CCh for the half maximum response for this preparation was about one five-hundredth that of cells prepared by the ordinary method. This value was approximately one-quarter that of intact tissue. This preparation can be used to investigate the physiology, pharmacology, and biochemistry of smooth muscle.

Animals↗
PubMed1988

The mode of inotropic action of ciguatoxin on guinea-pig cardiac muscle.

1. Ciguatoxin (CTX) caused a dose-dependent increase in the contractile force of the guinea-pig isolated left atria at concentrations ranging from 0.1 to 10 ng ml-1 with the ED50 value of 0.5 ng ml-1. 2. In the atria, tetrodotoxin (5 x 10(-7) M) inhibited markedly the inotropic action of CTX. The inotropic effect of CTX at low concentrations was abolished by practolol (10(-5) M) and reserpine (2 mg kg-1 daily, for 3 days), whereas that of CTX at high concentrations was partially inhibited by both drugs. 3. In single atrial cells, CTX (3 ng ml-1) produced a marked increase in the amplitude of longitudinal contractions. 4. CTX (3 ng ml-1) caused marked prolongation in the falling phase of action potentials of atrial strips without affecting the maximum rate of rise of action potentials and membrane resting potentials. The effect of CTX on action potentials was abolished by tetrodotoxin (10(-6) M). 5. The whole-cell patch-clamp experiments on myocytes revealed that CTX (20 ng ml-1) shifted the current-voltage curve of Na inward currents by 40 mV in the negative direction. CTX caused a small sustained Na inward current even at resting membrane potentials. 6. These results suggest that the inotropic action of lower concentrations of CTX is primarily due to an indirect action via noradrenaline release, whereas that of higher concentrations is caused not only by an indirect action but also by a direct action on voltage-dependent Na channels of cardiac muscle. It is also suggested that CTX activates cardiac muscle Na channels by modifying the voltage-dependence of channel activation to increase Na inward currents, thus producing cardiotonic actions.

Action Potentials↗
PubMed1988

Inositol 1,4,5-trisphosphate-induced contraction in skinned single smooth muscle cells from guinea-pig taenia coli.

Inositol 1,4,5-trisphosphate (IP3) caused a contraction in skinned single smooth muscle cells from the guinea-pig taenia coli. The contractile response to IP3 was rapid (half time less than 5 s), concentration-dependent (0.01-10 microM, EC50; 0.1 microM) and also depended on the concentration of Ca2+ during preloading. IP3 induced a rapid 45Ca2+ release from the skinned single cells which were preloaded with 10(-6) M Ca2+. The contractile response caused by IP3 was not enhanced by simultaneous application of caffeine (25 mM). The inhibitory effect of procaine on IP3-induced contraction was less than that on caffeine-induced contraction. These results suggest that IP3 also plays an important role in the contractile response in smooth muscle cells from guinea-pig taenia coli and that the mechanism of Ca2+ release from intracellular storage sites by IP3 is different from that by caffeine.

Animals↗
PubMed1987

Effect of DFP on loading of fura 2/AM and quin 2/AM into single smooth muscle cells prepared from guinea pig taenia coli.

The effect of diisopropyl fluorophosphate (DFP), a potent cholinesterase (ChE) inhibitor, on loading quin 2 acetoxymethyl ester (quin 2/AM) and fura 2/AM into smooth muscle cells isolated from guinea pig taenia coli was investigated spectrofluorometrically. The presence of DFP during the loading permitted the incorporation of quin 2 into the cells, so that it became possible to measure intracellular Ca2+ concentrations using the ester of this dye. Also, DFP significantly enhanced the incorporation of fura 2 into the cells. These results indicate that loading of quin 2/AM and fura 2/AM into the smooth muscle cells may depend on the suppression of ChE or various serine protease activities outside cells.

Aminoquinolines↗
PubMed1987

Preparation of single smooth muscle cells from guinea pig taenia coli by combinations of purified collagenase and papain.

Procedures for isolation of single smooth muscle cells from taenia coli of guinea pigs have been developed. The preparation was performed with a combination of highly purified collagenase prepared by Amano Pharmaceutical Co. (Japan) and papain obtained from Sigma Chemical Co. (Type III). This combination resulted in very high yield of the single cells (39.2 +/- 4.5 X 10(3) cells/mg tissue wet wt) and less cell debris. In the ordinary procedure, commercially available collagenase preparations contaminated with various peptidases have been used. With these enzyme preparations, however, the yield of single cells was dependent on the batch of the preparations, and a large amount of cell debris was contaminated. Combination of the highly purified collagenase and papain resulted in higher yields constantly. Cells, isolated with these enzymes in a medium consisting of 140 mM KCl, 1.0 mM MgCl2, 4.2 mM Hepes, and 5.6 mM glucose (pH 7.4), were spindle shaped. The length of the cells was 185.9 +/- 5.2 micron (n = 90) and the diameter was approximately 12.6 micron. The diameter was not dependent on the cell length. More than 80% of the single cells were viable when examined by trypan blue exclusion technique. Under the depolarized condition, cells remained viable longer because of lower energy consumption, and these cells were contracted by Ca dose dependently. The dose-response relationship was similar to that obtained with intact tissue. Because the cells are constantly available with higher yield, the preparation might be applicable for biochemical research such as ion flux. Details of cell properties under the physiological conditions are under investigation.

Animals↗
PubMed1987

Ultrastructure of single smooth muscle cells contracted by carbachol and calcium ion.

The ultrastructural changes of single smooth muscle cells of guinea pig taenia coli during contraction evoked by Ca2+ (Ca) and carbachol (CCh) were investigated by transmission and scanning electron microscopy. Cells, prepared in the presence of a high concentration (140 mM) of KCl, without addition of Ca, exhibited smooth surfaced contour. The contraction of these cells were dose dependent upon Ca. With the increase in Ca concentration, the contraction was accompanied with formation of processes (0.15 micron thick and 1 micron long), membrane evaginations of various sizes and shapes and cores densely packed with filaments at the bottoms of all evaginations. Cells, prepared in the presence of 0.18 mM Ca and at a physiological concentration (2.7 mM) of KCl, had two populations: One had shallow invaginations of the cell membrane and the other had spinous processes. Cells of both types were responsive to CCh and the spinous processes disappeared during contraction but evagination did not appear. Differences in ultrastructural changes during contractions between single smooth muscle cells and intact tissues may be due to the fact that single cells are mechanically free from adjacent cells and connective tissues. It is also possible that membrane properties change during isolation, particularly when cells are isolated in Ca free medium.

Animals↗
PubMed1987

Studies on isolated smooth muscle cells. IX. Application of papain for isolation of single smooth muscle cells from guinea-pig taenia coli.

To prepare single smooth muscle cells from the taenia coli of guinea pig, the application of papain to the enzymatic solution was examined under two conditions: 1) the isolation in a modified Tyrode solution (containing 0.18 mM Ca2+: 0.18 mM Ca2+-Tyrode solution) and 2) the isolation in a high-K+ Tyrode solution (Na+ was replaced by K+, and Ca2+ was not added: high-K+ Tyrode solution). The presence of papain during collagenase digestion reduced contamination of broken cells and cell debris. In the case of the high-K+ Tyrode solution, papain increased the yield of single cells significantly. The cells were contracted in a dose-dependent manner by Ca2+ in the high-K+ Tyrode solution and by carbachol in 0.18 mM Ca2+-Tyrode solution; furthermore, the contractions were antagonized by verapamil and atropine, respectively. Treatment with papain did not affect cell sensitivity to the stimulants. Therefore, our results suggest that the addition of papain is useful for the isolation of single cells to investigate the physiological and pharmacological characteristics of smooth muscle.

Animals↗
PubMed1987

Urinalysis for detection of chemically induced renal damage (1)--Changes in urinary excretions of enzymes and various components caused by mercuric chloride and gentamicin.

In order to establish sensitive methods of detecting minor renal damage, changes of enzymes, tubular cell counts, and creatinine in the urine were investigated in rats that had been given nephrotoxic chemicals. Daily administration of mercuric chloride (HgCl2) dose-dependently increased urinary excretions of lactate dehydrogenase (LDH), aspartate aminotransferase (GOT), alkaline phosphatase (ALP), leucine aminopeptidase (LAP), lysozyme (LZM), N-acetyl-beta-D-glucosaminidase (NAG), and acid protease together with increased counts of tubular cells in the urine. The increase in tubular cell counts and the change in urinary LDH isoenzyme profile preceded the changes in the other enzymes. Daily administration of gentamicin (GM) increased urinary excretions of LDH, GOT, LZM, NAG, acid protease and tubular cell counts in a dose-dependent manner, but did not increase gamma-glutamyl transpeptidase (gamma-GTP) and ALP excretions. The urinary isoenzyme profiles of LDH in rats treated with GM were different from those with HgCl2. The increase in acid protease excretion outlasted those in LDH and GOT in the high dose group. It was concluded that the severity of renal damage can be readily detected by periodic determinations of the following urinary parameters: tubular cell counts, LDH isoenzyme, acid protease, LZM and NAG, in addition to either LDH or GOT and one of the enzymes ALP, LAP or gamma-GTP. Furthermore, the site of renal damage can be presumed from these results.

Animals↗
PubMed1987

Urinalysis for detection of chemically induced renal damage (2)--Changes in urinary excretions of enzymes and various components caused by p-aminophenol, puromycin aminonucleoside and hexadimethrine.

In order to establish sensitive methods of detecting minor renal damage, changes of enzymes, protein, tubular cell counts, and creatinine in the urine were investigated in rats to which nephrotoxic chemicals had been administered. Daily administration of p-aminophenol (PAP) dose-dependently increased urinary excretions of lactate dehydrogenase (LDH) and its isoenzymes (LDH5 = LDH4 greater than LDH3 greater than LDH2 = LDH1), aspartate aminotransferase (GOT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (gamma-GTP), leucine aminopeptidase (LAP), lysozyme (LZM), N-acetyl-beta-D-glucosaminidase (NAG) and acid protease together with increased counts of tubular cells in the urine. Tubular cell counts, LDH and GOT were more sensitive indicators in the PAP tubulonephritis. Single i.v. injection of puromycin aminonucleoside (PM) dose-dependently increased urinary excretions of LDH and its isoenzymes (LDH1 = LDH5 greater than LDH2 = LDH4 greater than LDH3), GOT, NAG, acid protease and protein but degree of the increases in these enzymes was lower than those in the rats treated with PAP. PM increased excretions of high molecular weight proteins but did not increase ALP, gamma-GTP, LAP, LZM and tubular cells excretions. Single i.v. injection of hexadimethrine increased urinary excretion of LDH and its isoenzymes (LDH1 = LDH5 greater than LDH2 greater than LDH3 = LDH4), GOT, LZM, NAG and acid protease together with increased counts of tubular cells in the urine but did not increase ALP, gamma-GTP and LAP excretions. It is concluded that tubular cell counts, LDH isoenzymes and battery of these enzymes in urine are useful markers for detecting the severity and the site of renal damage in addition that urinary protein is a useful marker for detecting glomerular damage.

Aminophenols↗
PubMed1986

Calcitonin action on ATP citrate lyase activity in the hepatic cytosol of fed rats and its calcium-calmodulin dependency.

The effect of calcitonin (CT) on ATP citrate lyase activity in the hepatic cytosol was investigated after a single subcutaneous administration of the hormone to fed rats. Administration of CT (synthetic [Asu107] eel CT; 80 MRC mU/100 g body weight) produced significant increases in ATP citrate lyase 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 increased cytosolic ATP citrate lyase activity resulting from CT administration was prevented by treatment with 10 microM EGTA. This enzyme activity was restored by addition of calcium ion (2.5-10 microM). The rise in enzyme activity of CT-treated rats was markedly reduced by the presence of W-7 (10 and 100 microM), a calmodulin inhibitor, in the enzyme assay system, while that of control rats was not significantly altered by the drug. These results suggest that CT increases ATP citrate lyase activity in the hepatic cytosol of fed rats, and that this hormonal regulation may depend on calmodulin, and be mediated through raised calcium in the cytosol.

ATP Citrate (pro-S)-Lyase↗