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H Nishimatsu

Publications and source records attributed to H Nishimatsu.

31 records · Page 2Linked to original sources
PubMed2000

Effects of vasodilatory antihypertensive agents on endothelial dysfunction in rats with ischemic acute renal failure.

Ischemic acute renal failure is associated with vascular endothelial dysfunction. We examined whether vasodilatory antihypertensive agents would improve endothelial function in rats with ischemia/reperfusion renal injury. Rat kidneys were isolated and perfused after clipping of the bilateral renal arteries for 45 min and reperfusion for 24 h, and renal perfusion pressure and nitric oxide concentration in the venous effluent (chemiluminescence assay) were monitored. Preischemic administration of celiprolol (a beta-blocker; 100 mg/kg p.o.), benidipine (a calcium channel blocker; 1 mg/kg p.o.), or imidapril (an angiotensin converting-enzyme inhibitor; 3 mg/kg p.o.) restored endothelial function in rats subjected to acute renal ischemia (deltarenal perfusion pressure [10(-8) M acetylcholine]: sham -42+/-3%, ischemia -31+/-1%, ischemia +celiprolol -39+/-1%*, ischemia+benidipine -38+/-2%*, ischemia+imidapril -42+/-2%*; *p<0.05 vs. ischemia). Serum urea nitrogen and creatinine levels were also lower in the treated groups. Furthermore, ischemia-induced decreases in the response to acetylcholine and renal excretory function were smaller in SHR than in deoxycorticosterone-salt hypertensive rats, in which endothelial damage was marked. These results suggest that preischemic endothelial function may influence the degree of ischemic renal injury. Calcium channel blockers, converting-enzyme inhibitors, and endothelial NO synthase-activating beta-blockers had beneficial effects on renovascular endothelial dysfunction due to ischemia.

Acetylcholine↗
PubMed1999

Accelerated rejection of Fas ligand-expressing heart grafts.

The Fas/Fas ligand (FasL) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. Recently, there has been renewed interest in immune privilege, as it was shown that two privileged sites (the eye and testes) constitutively express FasL, which kills lymphoid cells that invade these areas. We have established murine FasL-transgenic mice (B6) under the control of the cardiac alpha-myosin heavy chain promotor, and transplanted FasL-expressing F1(B6 x C3H/HeJ) heart grafts into syngeneic (F1) and allogeneic (C3H/HeJ) recipients. FasL-expressing F1 heart allografts placed in C3H/HeJ recipients as well as FasL-expressing F1 isografts placed in nontransgenic and FasL-transgenic F1 were more rapidly rejected, and their survival was much shorter than that of nontransgenic control F1 allografts placed in C3H/HeJ. Native control and FasL-expressing hearts looked normal in mice up to 8 wk of age on hematoxylin-eosin staining. Control heart allografts undergoing ordinally acute rejection showed moderate focal lymphocyte infiltrates, while FasL-expressing F1 allografts and isografts showed massive hemorrhage, edema, and massive neutrophil infiltration as early as 1 day after transplantation. In conclusion, FasL expression and surgical procedure (ischemia/reperfusion) were synergistic in the induction of accelerated heart graft rejection, while allogenicity was not necessary. It may be necessary to find ways of controlling neutrophilic reaction/apoptosis in infiltrating lymphocytes to use FasL in clinical organ transplantation.

Animals↗
PubMed1999

CD95 ligand expression enhances growth of murine renal cell carcinoma in vivo.

The CD95/CD95 ligand (CD95L) system plays an important role in the induction of lymphoid apoptosis and has been implicated in the suppression of immune responses. In this system, two murine CD95L-transfected renca clones and a control renca clone transfected only with the vector were implanted into the subcapsule of the left kidney of Balb/c and Balb/c nude mice. Both CD95L-expressing and control renca clones formed macroscopic tumors in all of the Balb/c and Balb/c nude hosts 14 days after implantation. Growth of tumors of murine CD95L-transfected renca cells was significantly better than that of control renca cells in Balb/c mice, while the growth advantage of CD95L transfectants was not observed in Balb/c nude mice. Lymphocytes underwent apoptosis mainly in the periphery of the CD95L-expressing tumors but not in control tumors grown in Balb/c mice, while lymphocytes undergoing apoptosis were not observed in CD95L-expressing tumors or in control tumors grown in Balb/c nude mice. Neutrophilic recruitment was rarely observed in CD95L-expressing or control tumors. CD95L expressed on renca cells possibly suppressed immune responses against renca tumors by inducing apoptosis of the infiltrating lymphocytes. However, CD95L-expressing renca cells did not form tumors in the renal subcapsule of allogeneic C3H/HeJ mice.

Animals↗
PubMed1999

Age-related change of the role of alpha1L-adrenoceptor in canine urethral smooth muscle.

To examine age-related alteration of the role of alpha1L-adrenoceptor in the urethra, young non-parous and aged parous female dogs were used. In a functional study, we evaluated phenylephrine-induced contraction and antagonistic effects of JTH-601, a newly synthesized alpha1-adrenoceptor antagonist, and prazosin; in a localization survey using autoradiographic technique, we investigated specific [3H]JTH-601 and [3H]tamsulosin binding. Concentration-response curves were obtained for phenylephrine (pD2 = 5.0-5.3). JTH-601 and prazosin antagonized this contraction with pA2 values of 8.2-8.3 and 8.0-8.1, respectively. Specific binding of both [3H]JTH-601 and [3H]tamsulosin were observed in the bladder neck and proximal section of urethra. There were no significant differences of the pD2, pA2, and radio ligand binding between young non-parous and aged parous dogs.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed1999

Contractile responses to alpha1-adrenoceptor agonists in isolated human male and female urethra.

OBJECTIVE: To investigate the contractile responses mediated through alpha1-adrenoceptors in human urethra and to evaluate the effectiveness of NS-49 [(R)-(-)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethanesulphonanilide++ + hydrochloride], a novel alpha1-adrenoceptor agonist, against contraction of the human urethra. MATERIALS AND METHODS: The contractile responses were assessed in 10 male prostatic urethrae and six female urethrae. Antagonism was evaluated in the urethra using phenylephrine, a nonselective alpha1-adrenoceptor agonist, cumulatively applied > 20 min after applying 0.1 micromol/L prazosin or 0.1 micromol/L 5-methylurapidil, a selective alpha1A-adrenoceptor antagonist. Agonism was determined in both male and female urethrae to obtain the concentration-response curve for the agonist. RESULTS: Phenylephrine caused both male and female urethrae to contract, and showed high potency and efficacy. Prazosin antagonized these contractions with low affinity (apparent pKB of 8.30 in male urethrae). 5-Methylurapidil, also antagonized the contractions with low affinity (apparent pKB of 7.88 in male urethrae). Noradrenaline and phenylephrine caused both male and female urethrae to contract, with high potency and efficacy. A novel and selective alpha1A-and alpha1L-adrenoceptor agonist, NS-49, induced contractile responses with high potency and moderate efficacy, whereas methoxamine induced contractions with low potency and moderate efficacy. Norephedrine was a very weak contractile agonist. CONCLUSION: In the human urethra, phenylephrine-induced contractions were mediated through alpha1L-adrenoceptors and not through alpha1A-adrenoceptors. Contractions of the human urethra induced by NS-49 were also mediated mainly through alpha1L-adrenoceptors, with high potency and moderate efficacy. NS-49 may therefore be useful for the treatment of urinary stress incontinence, with minimal side-effects because it has subtype selectivity.

Adrenergic alpha-Agonists↗
PubMed1999

Effects of vasodilatory beta-adrenoceptor antagonists on endothelium-derived nitric oxide release in rat kidney.

The mechanisms for the vascular actions of vasodilatory beta-blockers remain undetermined. For some kinds of beta-blockers, the involvement of nitric oxide (NO) has been suggested. We studied the effects of vasodilatory beta-blockers on renal perfusion pressure (RPP) and NO release in the rat kidney. Infusion of bopindolol, celiprolol, and nebivolol caused a dose-dependent reduction in RPP and an increase in NO release (RPP: bopindolol 10(-6) mol/L, -23+/-2%; celiprolol 10(-4) mol/L, -27+/-2%; nebivolol 10(-5) mol/L, -35+/-3%; NO: bopindolol 10(-6) mol/L, +33+/-2; celiprolol 10(-4) mol/L, +41+/-2; nebivolol 10(-5) mol/L, +45+/-5 fmol. min-1. g kidney-1, mean+/-SEM). Metergoline (10(-6) mol/L), a 5-hydroxytryptamine (5-HT)1/2 antagonist, or NAN-190 (10(-6) mol/L), a 5-HT1A antagonist, almost completely abolished the vasorelaxation and NO release caused by bopindolol, celiprolol, and nebivolol. However, neither propranolol nor bisoprolol decreased RPP. Celiprolol and nebivolol caused vasodilation in the rat thoracic aorta, and it was markedly reduced by endothelial denudation, Nomega-nitro-L-arginine methyl ester (10(-4) mol/L), or NAN-190 (10(-6) mol/L). In deoxycorticosterone acetate-salt hypertensive rats, 4-week administration of celiprolol (50 mg. kg-1. d-1 IV) restored the responses regarding RPP and NO release to acetylcholine. These results suggest that several beta-blockers exert their vasodilatory action through the 5-HT1A receptor/NO pathway and that treatment with these beta-blockers may protect against endothelial injury in hypertension.

Adrenergic beta-Antagonists↗
PubMed1999

Role of nitric oxide-cGMP pathway in adrenomedullin-induced vasodilation in the rat.

We previously reported that adrenomedullin (AM), a potent vasodilator peptide discovered in pheochromocytoma cells, stimulates nitric oxide (NO) release in the rat kidney. To further investigate whether the NO-cGMP pathway is involved in the mechanisms of AM-induced vasodilation, we examined the effects of E-4021, a cGMP-specific phosphodiesterase inhibitor, on AM-induced vasorelaxation in aortic rings and perfused kidneys isolated from Wistar rats. We also measured NO release from the kidneys using a chemiluminescence assay. AM (10(-10) to 10(-7) mol/L) relaxed the aorta precontracted with phenylephrine in a dose-dependent manner. Denudation of endothelium (E) attenuated the vasodilatory action of AM (10(-7) mol/L AM: intact (E+) -25.7+/-5.2% versus denuded (E-) -7. 8+/-0.6%, P<0.05). On the other hand, pretreatment with 10(-8) mol/L E-4021 augmented AM-induced vasorelaxation in the intact aorta (-49. 0+/-7.9%, P<0.05) but not in the denuded one. E-4021 also enhanced acetylcholine (ACh)-induced vasorelaxation in the rat intact aorta (10(-7) mol/L ACh -36.6+/-8.4% versus 10(-8) mol/L E-4021+10(-7) mol/L ACh -62.7+/-3.1%, P<0.05). In perfused kidneys, AM-induced vasorelaxation was also augmented by preincubation with E-4021 (10(-9) mol/L AM -15.4+/-0.6% versus 10(-8) mol/L E-4021+10(-9) mol/L AM -23.6+/-1.2%, P<0.01). AM significantly increased NO release from rat kidneys (DeltaNO: +11.3+/-0.8 fmol. min-1. g-1 kidney at 10(-9) mol/L AM), which was not affected by E-4021. E-4021 enhanced ACh-induced vasorelaxation (10(-9) mol/L ACh -9.7+/-1.7% versus 10(-8) mol/L E-4021+10(-9) mol/L ACh -18.8+/-2.9%, P<0.01) but did not affect ACh-induced NO release from the kidneys. In the aorta and the kidney, 10(-4) mol/L of NG-nitro-L-arginine methyl ester, an NO synthase inhibitor, and 10(-5) mol/L of methylene blue, a guanylate cyclase inhibitor, reduced the vasodilatory effect of AM. These results suggest that the NO-cGMP pathway is involved in the mechanism of AM-induced vasorelaxation, at least in the rat aorta and kidney.

Adrenomedullin↗
PubMed1998

A-W glass ceramic as a bone substitute in cemented hip arthroplasty: 15 hips followed 2-10 years.

We retrospectively reviewed hip arthroplasties in 13 patients (15 hips), in whom we had used apatite-wollastonite (A-W) glass ceramic together with auto- or allograft for augmentation of severe bone deficiency. 11 cemented sockets and 4 stem revisions were included and followed for 2-9.6 years. There were no radiolucent lines between A-W glass ceramic and surrounding bone, and remodeling of the bone graft containing A-W glass ceramic was observed. No migration of cemented sockets was seen except in 1 case, which was revised. In this case, direct bonding between bone and A-W glass ceramic granules was present histologically. In 4 stem revisions, 5 mm subsidence occurred in 1 case. However, the stem became stable and remodeling of the grafted bone occurred. An artificial bone material, such as A-W glass ceramic, can be used under high-load conditions, because of its good mechanical properties.

Adult↗
PubMed1997

Quantification and distribution of alpha 1-adrenoceptor subtype mRNAs in human vas deferens: comparison with those of epididymal and pelvic portions.

1. This study was intended to quantify the amounts of the alpha 1-adrenoceptor subtype mRNAs in human vas deferens, and demonstrate the receptor subtype responsible for the vas contraction. 2. The RNase protection assay showed that the mean total amount of alpha 1a mRNA was 7.4 +/- 2.2 pg/5 micrograms of poly (A)+ RNA (97.0% of the total alpha 1 mRNA) in the epididymal portion (E-vas) and 4.9 +/- 0.8 pg/5 micrograms of poly (A)+ RNA (96.3% of the total) in the pelvic portion (P-vas). The E-vas showed a tendency to have a greater alpha 1a mRNA abundance than the P-vas (P = 0.11). The alpha 1b and alpha 1d mRNAs were absent or of extremely low abundance. 3. By an in situ hybridization, the alpha 1a and alpha 1d mRNAs were recognized in the smooth muscle cells of the E-vas and the P-vas, and the distribution pattern the same in both tissue. The alpha 1b mRNA positive site was scarcely detectable in both vas portions. 4. In a functional study, l-phenylephrine produced concentration-dependent contraction in the E-vas (Emax = 2.24 +/- 0.70 g; pD2 = 5.32 +/- 0.09) and the P-vas (Emax = 2.46 +/- 0.46 g; pD2 = 5.07 +/- 0.12). KMD-3213, a novel alpha 1A-adrenoceptor-selective antagonist, caused parallel rightward shifts of the concentration-response curves for l-phenylephrine. Apparent pKB values were 9.90 +/- 0.16 for the E-vas and 9.71 +/- 0.17 for the P-vas. There was no significant difference in Emax, pD2 or pKB estimates between the two portions. 5. We have found that alpha 1a mRNA is predominant in the human vas deferens, and confirmed that contraction of this organ is mediated by the alpha 1A-adrenoceptor.

Aged↗
PubMed1997

Fatal pulmonary embolism after total hip arthroplasty. Three Japanese cases.

It has been reported that the incidence of postoperative pulmonary embolism is significantly lower in Asians than in Westerners, however, several recent reports have cited an increase in the incidence in Asia. We have experienced three cases of fatal pulmonary embolism after total hip replacement in Japanese patients. Our three patients had received no preoperative prophylaxis, even though they had risk factors for pulmonary embolism. Prophylaxis for pulmonary embolism seems necessary in Asian patients who are at risk.

Adult↗
PubMed1994

The effects of intraoperative radiotherapy on bone-healing ability in relation to different doses and postradiotherapy intervals.

PURPOSE: Alterations in bone-healing ability after intraoperative radiotherapy were investigated in relation to different doses and postradiotherapy intervals in an experimental model. METHODS AND MATERIALS: Bilateral osteotomy of the fibulae of 56 rabbits was carried out either immediately, 13 weeks or 39 weeks after unilateral intraoperative radiotherapy with 10-MV X ray using one of three doses, 25, 50, or 100 Gy. The healing of the fibulae was evaluated radiographically and histologically 13 weeks after the osteotomy. RESULTS: Bone-healing ability was irreversibly reduced in all irradiated fibulae and these damages occurred in a dose-dependent manner. The severity of the damage also tended to increase with the time interval between irradiation and osteotomy. This interval-related aggravation was characterized by augmented bone loss at the osteotomy ends and atrophy of the neighboring areas. CONCLUSION: These results serve as useful information concerning the surgical intervention of irradiated bone during and after intraoperative radiotherapy, and also after conventional radiotherapy.

Animals↗
PubMed1992

[Malignant lymphoma with subdural effusion].

A 64-year-old woman was admitted for treatment of malignant lymphoma involving the pharynx and abdomen. Lymphoma disappeared after chemotherapy and radiotherapy, but she had central nervous system symptoms; euphorism, left facial nerve palsy, right hemiplesia, and disturbance of micturition. Magnetic resonance imaging (MRI) revealed a diffuse dural thickening and a subdural fluid retention. The subdural fluid was determined to be an exudate, and a biopsy of the dura mater revealed a normal dura and a fibrin clot containing lymphoma cells and neutrophils. MRI can be very useful to detect the meningeal involvement of malignant lymphoma.

Female↗