Biomedical subjects

K Uezu

Publications and source records attributed to K Uezu.

23 records · Page 2Linked to original sources

PubMed1993

Ex vivo effect of insulin on normal and diabetic rat hearts hypoperfused with norepinephrine.

The effect of ex vivo insulin on contractile and energy metabolism dysfunctions was examined during hypoperfusion (0.6 ml/min per g heart weight) with 10(-6) M norepinephrine in isolated non-diabetic and streptozotocin-diabetic rats hearts. Insulin (2 mU/min per g heart weight) was infused for 15 min before as well as during 60-min hypoperfusion. Insulin significantly reduced the elevated diastolic tension in diabetic hearts (from 3.8 to 0.7 delta g), but not in non-diabetic hearts (from 1.4 to 1.2 delta g). Insulin partly improved the ATP decrease in the subendocardium of the left ventricle of the diabetic hearts (from 3.5 to 10.2 mumol/g dry weight) but did not affect non-diabetic hearts (from 6.9 to 6.8 mumol/g dry weight). Insulin also partly improved the creatine phosphate decrease and the inorganic phosphate increase in diabetic hearts only. Lactate accumulation was greater in non-diabetic than in diabetic hearts, even in the presence of insulin (77 vs. 45 mumol/g dry weight). The results indicate that acute intracoronary application of insulin in diabetic hearts improves hypoperfusion with norepinephrine injury to a level above that of non-diabetic hearts, but does not improve a less severe injury in non-diabetic hearts.

Animals↗

PubMed1992

Possibilities of the tolerance development to nipradilol and of the measurement of vascular glutathione content in isolated rat aorta.

1. Nipradilol produced concentration-dependent relaxations of isolated rat aorta ring preparations under the contracture induced by norepinephrine or KCl, which were not significantly influenced by the previous incubation with nipradilol but significantly depressed by methylene blue. 2. The previous incubation with nipradilol did not influence the relaxant responses to nitroglycerin. 3. Five different methods for measurement of vascular glutathione content did not give the satisfiable results on the detected value of glutathione content in isolated rat aorta tissues. 4. Results indicate that nipradilol will not develop the tolerance to nipradilol itself and nitroglycerin.

Animals↗

PubMed1992

Effects of denopamine with or without diltiazem on the ischemic heart of anesthetized dogs.

Effects of denopamine with or without diltiazem on the ischemic heart were investigated in anesthetized open-chest dogs. Partial occlusion of the left circumflex coronary artery (LCX) produced significant decreases in LCX flow and regional myocardial segment shortening rate (%SS) in the LCX-perfused area, and a significant increase in left ventricular enddiastolic pressure (LVEDP). Heart rate (HR) and mean aortic pressure (mAoP) were not altered, but aortic flow (AoF), positive first derivative of left ventricular pressure ((+)LVdP/dt), stroke volume (SV), stroke work index (SWI) and double product showed a tendency to decrease. Total peripheral vascular resistance (TPR) tended to increase. During coronary stenosis, saline infusion (vehicle group) did not change any parameter, but diltiazem infusion (diltiazem group) decreased HR, mAoP, TPR and double product and increased SV and SWI. Under these conditions, denopamine infusion produced increases in HR, mAoP, AoF, (+)LVdP/dt and double product and decreases in LVEDP and TPR in both groups. %SS in the left anterior descending coronary artery-perfused area was increased, but %SS in the LCX-perfused area was slightly decreased in both groups. SV and SWI were decreased by denopamine infusion in the vehicle group, while they were increased in the diltiazem group. Differences in changes in SV and SWI between the groups were statistically significant. Results suggest that combined treatment of denopamine and diltiazem may exert an advantage in alleviation of heart failure due to coronary stenosis.

Adrenergic beta-Agonists↗

PubMed1992

Effects of the new thromboxane A2 antagonist vapiprost on isolated canine blood vessels.

Effects of the new thromboxane A2 antagonist vapiprost (SN-309, GR-32191B, CAS 85505-64-2) on isolated canine blood vessels were investigated. U46619 ((15S)-hydroxy-11a, 9a-(epoxymethano) prosta-5Z, 13E-dienoic acid) 10(-10)-10(-6) mol/l, a thromboxane A2 analogue, produced concentration-dependent contractions of oblong or ring preparations isolated from basilar, coronary, mesenteric and femoral arteries. Vapiprost 10(-8) and 10(-7) mol/l significantly and concentration-dependently shifted the concentration-contraction curves for U46619 of these arteries to the right. The pA2 values were 8.80 +/- 0.09 in basilar arteries, 8.67 +/- 0.12 in coronary arteries, 8.86 +/- 0.05 in mesenteric arteries and 9.01 +/- 0.07 in femoral arteries. On the other hand, oblong or ring preparations of basilar, coronary, mesenteric and femoral arteries showed sustained contractile responses to KCl 3 x 10(-2) mol/l, U46619 10(-7) mol/l or prostaglandin (PG) F2 alpha 10(-5) mol/l. Norepinephrine (NE) 3 x 10(-5) mol/l also produced sustained contractions in mesenteric and femoral arterial preparations, but not in basilar and coronary arterial preparations. Vapiprost 10(-10)-3 x 10(-6) mol/l relaxed these four arterial preparations constricted with U46619 10(-7) mol/l and PGF 2 alpha 10(-5) mol/l in a concentration-dependent fashion, but hardly affected them constricted with KCl 3 x 10(-2) mol/l. NE 3 x 10(-5) mol/l-induced contractures of mesenteric and femoral arterial preparations were not influenced by any concentrations of vapiprost. Results indicate that vapiprost has an antagonistic action on a so-called TP-receptor and/or a vasoconstrictive prostaglandin(s)-receptor and thus produces vasorelaxation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed1986

[Clinical study of spinal cord compression due to metastatic epidural tumors].

Eleven patients with spinal cord compression due to metastatic epidural tumors were analyzed. Primary tumors were Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma (two patients each), cervical cancer, malignant melanoma, gastric cancer, lung cancer, and neuroblastoma (one patient each). It was felt that myelography is the most important diagnostic test, although CT scan and bone scan may give further diagnostic information in some patients. Six patients were treated with decompressive laminectomy and postoperative radiotherapy, and five with radiotherapy alone. Regardless of the pretreatment neurological status and the type of treatment given, the functional prognosis in our small series of patients appeared to be favorable for radiosensitive tumors such as malignant lymphoma and multiple myeloma.

Adult↗