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T Noto

Publications and source records attributed to T Noto.

At least 19 recordsLinked to original sources
PubMed1992

The inhibitory action of cyclic AMP on responses to carbachol dependent on calcium stores in rat gastric smooth muscle.

1. The effects of cyclic AMP on contraction and Ca(2+)-activated K+ currents induced by carbachol (CCh), caffeine and inositol 1,4,5-trisphosphate (InsP3) were examined in intact and skinned smooth muscle fibres and in whole-cell voltage-clamped smooth muscle cells of the rat stomach. Intracellular Ca2+ level, [Ca2+]i, was monitored in intact muscle fibres loaded with Fura-2. 2. In intact muscle fibres, dibutyryl cyclic AMP, 8-bromo-cyclic AMP and forskolin inhibited a phasic contraction induced by CCh (100 microM) much more extensively than that induced by caffeine (30 mM) in Ca(2+)-free solution containing 2 mM-EGTA. A rise in [Ca2+]i evoked by CCh was also reduced by dibutyryl cyclic AMP. 3. In skinned muscle fibres, InsP3 (40 microM) produced a contraction of amplitude similar to that evoked by caffeine (30 mM) in Ca(2+)-free solution containing 0.05 mM-EGTA. Cyclic AMP suppressed the InsP3-induced contraction to a much greater extent than that induced by caffeine. 4. In cells voltage-clamped at 0 mV, CCh (100 microM) evoked a transient Ca(2+)-activated outward K+ current in 61% of cells tested. After wash-out of CCh, caffeine (10 mM) evoked a similar K+ current in all cells. In cells loaded with cyclic AMP (100 microM), the percentage of cells responding to CCh was reduced to 26% and the magnitude of current response tended to decrease. Cyclic AMP caused a small increase in the caffeine-induced K+ current. 5. An outward current was elicited immediately after the patch membrane was ruptured at a holding potential of 0 mV, using a patch pipette containing InsP3 (40 microM), in 76% of cells tested. In cells treated with dibutyryl cyclic AMP, the percentage of cells responding to InsP3 was reduced to 50% and the magnitude of current response tended to decrease. 6. In intact muscle fibres loaded with Fura-2, the relationship between [Ca2+]i and tension development shifted to the right in the presence of dibutyryl cyclic AMP. In skinned muscle fibres, cyclic AMP shifted the pCa-tension relation to the right, suggesting that cyclic AMP inhibits the contractile machinery directly. 7. These results suggest that the inhibitory effect of cyclic AMP on muscarinic receptors mediating both the contraction and the Ca(2+)-activated K+ current, is partly due to the inhibition of InsP3-induced Ca2+ release from intracellular stores in rat gastric smooth muscle cells.

Animals↗
PubMed1992

Effect of anoxic preperfusion on ischemic myocardial injury in isolated rat hearts.

Anoxic perfusion prior to sustained ischemia (anoxic preperfusion), reportedly improves postischemic functional recovery of the heart, but its mechanism has not been well understood. The present study aimed to characterize the cardioprotective effects of anoxic preperfusion and its relationship to extracellular Ca++ levels. Following 10 min of aerobic perfusion, isolated rat hearts were assigned to a 10 min aerobic perfusion or to a 10 min anoxic perfusion. The hearts were then subjected to 30 min of global ischemia and 30 min of aerobic reperfusion. When the perfusate-free Ca++ concentration was 2.0 mM, postischemic recovery of left ventricular developed pressure was significantly improved by anoxic preperfusion (91.9 +/- 2.9% of baseline value vs. 50.5 +/- 12.9% after 30 min reperfusion in the controls). However, the improvement of postischemic ventricular function by anoxic preperfusion was abolished when perfusate Ca++ was reduced to 1.0 mM and the contractile function was rather suppressed during early reperfusion by anoxic preperfusion when the Ca++ level was 0.7 mM (87.5 +/- 11.8% vs. 115.6 +/- 13.9% after 10 min of reperfusion). On the other hand, lactate accumulation during the global ischemia was significantly less in anoxic preperfused hearts compared with untreated hearts both when perfusate Ca++ was 0.7 mM (61.3 +/- 5.1 vs. 85.9 +/- 6.8 mumol/g dry) and when it was 2.0 mM (43.8 +/- 2.0 vs. 140.3 +/- 14.1 mumol/g dry). The amount of myoglobin released after global ischemia was not different between untreated and anoxic preperfused hearts regardless of the perfusate Ca++ level. The results suggest that anoxic preperfusion does not reduce ischemic myocardial necrosis, but it attenuates myocardial stunning. That effect of anoxic preperfusion on the stunning is dependent on the extracellular Ca++ level and is not totally explained by suppression of ischemia-induced lactate accumulation.

Adenosine Triphosphate↗
PubMed1992

Two cases of adenolipoma of the breast.

Adenolipoma of the breast is a rare tumor. Two cases are described here and the literature is reviewed. Case 1 was a 52-year-old woman who had a 3-cm-long elastic hard tumor in the left breast. Case 2 was a 40-year-old woman who had a 3-cm-long elastic soft tumor in the left breast. In each case, mammography revealed well demarcated soft tissue density. Ultrasonography demonstrated well defined tumors composed of echogenic and sonolucent areas. These tumors were easily enucleated at surgery. Histologically, the tumors consisted of mammary ducts, fibrous stroma and adipose tissue, findings which are characteristic of mammary adenolipoma. An adenolipoma may still be misdiagnosed as a fibroadenoma or a fibrocystic disease. Characteristic findings of mammography and ultrasonography are emphasized.

Adenofibroma↗
PubMed1979

Effects of vasopressin and cyclic AMP on water transport at arachnoid villi of cats.

The effects of vasopressin and cyclic AMP on water transport at arachnoid villi into the superior sagittal sinus were examined using the isolated meninges preparations of cats. The meninges preparation, the superior sagittal sinus of which was opened at the midline of the outer surface, was held between two polyethylene tubes. The tubes were fixed vertically in the way that the opened surface of the sinus was directed downward and arachnoid surface upward. Water transport was determined by measuring the tritiated water dripping through the membrane preparation. Vasopressin from less than 50 to 500 muU/ml accelerated the water transport and this effect was dose-dependent. Cyclic AMP from 0.5 to 10 mM was proved to manifest the same effect as vasopressin. This effect of cyclic AMP appeared rapidly in comparison with that of vasopressin, suggesting that the effect of vasopressin may be manifested through cyclic AMP. From these findings a physiological role of vasopressin in cerebrospinal fluid was discussed regarding the regulation of intracranial pressure.

Animals↗
PubMed1978

Urinary metabolites of polyamines in rats.

Urinary metabolites of polyamines in rats were studied systematically by the intraperitoneal injection of radioactive polyamines. Urinary metabolites were fractionated into 4 fractions containing non-polar and acidic compounds, acidic and neutral ampholytes, basic ampholytes and polyamines. A large amount of radioactivity was detected in the fractions containing non-polar and acidic compounds and polyamines of urine of rats injected with radioactive putrescine, while in the case of the injection of radioactive spermidine or spermine a relatively large amount of radioactivity was found in the basic ampholyte fraction as well as in the polyamine fraction. Analysis of these fractions indicated that gamma-aminobutyric acid, N-monoacetylputrescine, 2(3)-hydroxyputrescine, putreanine, N-(3-aminopropyl)-4-aminobutyric acid (isoputreanine), spermic acid, N-(3-aminopropyl), N'-(2-carboxyethyl)-1,4-diaminobutane, and N-monoacetylspermidine A and B were excreted as urinary metabolites of the polyamines in addition to putrescine, spermidine and spermine.

Animals↗
PubMed1978

Effect of vasopressin on intracranial pressure of rabbit.

Effect of vasopressin on intracranial pressure (ICP) was examined by an intraventricular administration of the hormone to a rabbit. ICP was determined at the cisterna magna with a manometer and recorded automatically with a recorder. An injection of over 150 micro U of vasopressin lowered ICP, but there was no clear dose-response relationship of the effect of vasopressin on ICP. When vasopressin was injected intraventricularly after lowering ICP by an intravenous injection of acetazolamide which inhibits the production of cerebrospinal fluid (CSF), an additive effect of the hormone on ICP was observed. The effect of vasopressin on excretion of water in CSF was examined by the determination of drainage of tritiated water injected into the lateral ventricle of a rabbit. Drainage of radioactive water into vein was measured by collection of blood at the internal jugular vein and radioactivity of the plasma was counted. Vasopressin accelerated excretion of tritiated water into vein. These results indicate that vasopressin facilitated drainage of CSF into vein to lower ICP.

Acetazolamide↗
PubMed1978

A direct enzyme-linked immunosorbent assay (ELISA) for detection of antibodies for rubella virus in human sera.

A direct enzyme-linked immunoassay (ELISA), based on the "sandwich" principle on an antigen-coated plastic disc, was used for the rapid detection of rubella antibody. Results were obtained the same day, and the prior adsorption of sera to remove non-specific inhibitors was not necessary. The ELISA was compared to the hemagglutination-inhibition (HAI) test on 500 serum samples. There was general agreement between the two methods; most discrepancies occurred with low-titered HAI positive sera. There was excellent correlation between the tests with serum samples negative for rubella antibodies and those samples with HAI titers greater than or equal to 1:40.

Animals↗
PubMed1978

A totally automated system for enzyme immunoassay of theophylline in serum.

We describe a procedure for enzyme immunoassay of theophylline (1,3-dimethylxanthine) in which all phases of the assay are totally automated in a Kinetic Analyzer (KA-150). This system permits assay of 75 10-mul samples per hour, with results available at 30-s intervals after initial sample preparation and preincubation. We compared results for 138 clinical samples by an ultraviolet method (x) and the present method (y). The slope of the comparison curve was 0.902, the y-intercept 0.402, and the correlation coefficient 0.984. The coefficient of variation for samples run in duplicate on the same day was 4.9%; it was 8.1% for samples run on different days. Specificity, sensitivity, simplicity, speed, and small reagent requirement all make this an attractive alternative to chromatographic procedures.

Autoanalysis↗