Biomedical subjects

S Satoh

Publications and source records attributed to S Satoh.

At least 19 recordsLinked to original sources

PubMed1992

Cell surface accessibility of GLUT4 glucose transporters in insulin-stimulated rat adipose cells. Modulation by isoprenaline and adenosine.

Insulin-stimulated glucose transport activity in rat adipocytes is inhibited by isoprenaline and enhanced by adenosine. Both of these effects occur without corresponding changes in the subcellular distribution of the GLUT4 glucose transporter isoform. In this paper, we have utilized the impermeant, exofacial bis-mannose glucose transporter-specific photolabel, 2-N-4-(1-azi-2,2,2-trifluoroethyl)benzoyl-1,3-bis-(D-mannos- 4-yloxy)-2-propylamine (ATB-BMPA) [Clark & Holman (1990) Biochem. J. 269, 615-622], to examine the cell surface accessibility of GLUT4 glucose transporters under these conditions. Compared with cells treated with insulin alone, adenosine in the presence of insulin increased the accessibility of GLUT4 to the extracellular photolabel by approximately 25%, consistent with its enhancement of insulin-stimulated glucose transport activity; the plasma membrane concentration of GLUT4 as assessed by Western blotting was unchanged. Conversely, isoprenaline, in the absence of adenosine, promoted a time-dependent (t1/2 approximately 2 min) decrease in the accessibility of insulin-stimulated cell surface GLUT4 of > 50%, which directly correlated with the observed inhibition of transport activity; the plasma membrane concentration of GLUT4 decreased by 0-15%. Photolabelling the corresponding plasma membranes revealed that these alterations in the ability of the photolabel to bind to GLUT4 are transient, as the levels of both photolabel incorporation and plasma membrane glucose transport activity were consistent with the observed GLUT4 concentration. These data suggest that insulin-stimulated GLUT4 glucose transporters can exist in two distinct states within the adipocyte plasma membrane, one which is functional and accessible to extracellular substrate, and one which is non-functional and unable to bind extracellular substrate. These effects are only observed in the intact adipocyte and are not retained in plasma membranes isolated from these cells when analysed for their ability to transport glucose or bind photolabel.

Adenosine↗

PubMed1992

Atrial natriuretic peptide suppresses renal vasoconstriction induced by angiotensin II and norepinephrine in dogs.

Atrial natriuretic peptide (ANP, 10 and 50 ng/kg per min), infused into the renal artery, suppressed decreases in renal blood flow induced by intrarenal arterial injection of angiotensin II (Ang II, 25-100 ng) and norepinephrine (NE, 0.25-1 microgram) in anesthetized dogs. Sodium nitroprusside (SNP, 0.1-5.0 micrograms/kg per min) slightly attenuated the blood flow response to Ang II but not the response to NE. 8-Bromo cyclic GMP (8bcGMP, 0.5-25 micrograms/kg per min) did not suppress the blood flow response to Ang II. Although at a high dose ANP attenuated the blood flow response to Bay K 8644 (1-4 micrograms), nifedipine pretreatment (20 micrograms/kg plus 1 microgram/kg per min i.v.) did not affect the inhibitory effect of ANP on the NE-induced response. The vaso-inhibitory effects of ANP therefore could not be related exclusively to stimulation of cGMP production or inhibition of voltage-dependent Ca2+ channels.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1992

Role of acetylcholinesterase in airway epithelium-mediated inhibition of acetylcholine-induced contraction of guinea-pig isolated trachea.

To seek evidence for the involvement of acetylcholinesterase activity in the modulatory influence of the airway epithelium, we examined responses to acetylcholine (ACh), bethanechol, histamine or KCl in isolated epithelium-intact and epithelium-denuded guinea-pig trachealis preparations. The concentration-response curves to ACh were shifted 26-fold to the left by epithelial denudation but the contractile response to KCl was not altered. The response to histamine in epithelium-denuded preparations increased 4-fold with no attenuation in the presence of physostigmine (30 nM). Physostigmine (30 nM) potentiated the response to ACh in epithelium-intact tissues more (about 26-fold) than in epithelium-denuded tissues (about 3.5-fold). Thus, in the presence of physostigmine removing the epithelium had only a slight effect (not statistically significant) on the potency of ACh to contract the trachea. Removing the epithelium had no effect on the potency of bethanechol, a muscarinic receptor agonist that is not a substrate for cholinesterases. Physostigmine itself contracted the trachealis muscle but the pD2 values and maximum responses in epithelium-intact and denuded preparations were not significantly different. The frequency-response curves to electrical field-stimulated cholinergic contractions were unaffected by removing the epithelium. In conclusion, the principal mechanism by which the epithelium inhibits contraction of guinea-pig trachea to exogenously applied ACh is via epithelium-derived acetylcholinesterase activity.

Acetylcholine↗

PubMed1992

Possible prophylactic potential of HA1077, a Ca2+ channel antagonist and vasodilator, on chronic cerebral vasospasm.

We examined the possible prophylactic potential of HA1077, a calcium antagonist and vasodilator, on chronic cerebral vasospasm induced in a two-hemorrhage canine model, and also its effects on cerebral hemodynamics. The intravenous infusion of HA1077 3 mg/kg over 30 min twice daily (day 1-day 7) after the first intracisternal injection of 5 ml autologous blood significantly prevented the occurrence of chronic cerebral vasospasm. The mean diameter of the basilar arteries on day 7 was 66.1 +/- 1.6% (n = 7) of the baseline before the intracisternal injection of blood, compared to 54.2 +/- 1.6% (n = 9) of the baseline in the untreated group (P less than 0.01). Bolus intravenous administration of HA1077 (0.1 and 0.3 mg/kg) dose dependently increased local cerebral blood flow. Since HA1077 prevents the development of chronic cerebral vasospasm after subarachnoid hemorrhage and improves hemodynamic functions, as manifested by increases in local cerebral blood flow, further study is warranted regarding the possible clinical use of this drug.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1992

A marine algal Na(+)-activated ATPase possesses an immunologically identical epitope to Na+,K(+)-ATPase.

Immunological homology was investigated between Heterosigma akashiwo (a marine algae) Na(+)-activated ATPase and animal Na+,K(+)-ATPase. The former polypeptide [(1989) Plant Cell Physiol. 30, 923-928] reacted with anti-serum raised against the amino-terminal half of the pig kidney Na+,K(+)-ATPase alpha subunit. It is suggested that the Na+,K(+)-ATPase epitope within the amino-terminal region is conserved in the plant Na(+)-activated ATPase, and the region containing the epitope may be important for Na ion transport.

Antibodies↗

PubMed1992

[Immunohistochemical studies of the localization of prolactin in human term chorion laeve].

Human amniotic fluid contains a very high concentration of PRL. And it is widely accepted that decidual cells are the origin of amniotic fluid PRL, and decidual cell PRL is transported into amniotic fluid across the fetal membranes. However, the decidual cells are, in their lower aspect, in contact with chorion cells. Because of this complex structural relationship, decidual cells are often called decidua-chorion cells, besides, chorion PRL reproduction remains to be elucidated. Consequently, we further examined tissue of chorion laeve which had been obtained at spontaneous term vaginal delivery. The results of our examinations are as follows; 1. Chorion PRL was determined with precipitation method of radioimmunoassay, and it was concluded that chorion tissue contains no small amounts of human PRL; 391 +/- 24 ng/g in tissue, whereas decidual PRL was 225 +/- 91 ng/g in tissue. 2. Using immunohistochemical procedures and PAP complex methods, immunized anti-ovine PRL serum revealed PRL reactivity around the numerous granules or globules in term chorion cells. These data suggest that the chorion cells are the site of reproducible PRL localization and synthesis and, comparable to decidual cells, are the possible source of human PRL in term fetal membrane.

Chorion↗

PubMed1992

Immunocytochemical demonstration of IGF-II immunoreactivity in human phaeochromocytoma and extra-adrenal abdominal paraganglioma.

Insulin-like growth factor (IGF)-II immunoreactivity was demonstrated in 14 adrenal glands, six retroperitoneal paraganglia, 18 phaeochromocytomas, and six extra-adrenal abdominal paragangliomas through the use of a monoclonal antibody against rat IGF-II which cross-reacts with human IGF-II. A subpopulation of parenchymal cells in normal adrenal medulla and in retroperitoneal paraganglia was positively immunolabelled. Eighteen cases with phaeochromocytoma including two malignant and four multiple endocrine neoplasias all contained numerous IGF-II-immunoreactive tumour cells. All six extra-adrenal abdominal paragangliomas contained numerous immunoreactive tumour cells. Almost all the other normal human adult tissues examined failed to immunolabel. These results indicate that IGF-II-like immunoreactivity is widely expressed in normal and neoplastic human paraganglionic tissues, although its biological significance in these tissues has not been determined.

Abdominal Neoplasms↗

PubMed1992

Isolation and characterization of a cDNA that encodes ECP31, an embryogenic-cell protein from carrot.

A full-length cDNA for ECP31, an embryogenic cell protein from carrot (Daucus carota L.) with a M(r) of 31,000 (Kiyosue T, Satoh S, Kamada H, Harada H (1991) Plant Physiol 95: 1077-1083), was isolated from a cDNA library prepared from embryogenic cells using PCR-amplified DNA as a probe. The genomic Southern blot analysis revealed that there are two or three genes for ECP31 in the carrot genome. The transcripts of ECP31 accumulated in the peripheral regions of clusters of embryogenic cells and disappeared in the course of somatic embryogenesis that was induced by transfer of the embryogenic cells to auxin-free media. The cDNA encodes a polypeptide of 256 amino acids, and the calculated molecular weight of this polypeptide is 26,111. The deduced amino acid sequence shows a high degree (62.2%) of similarity to that of a protein that is abundant during late embryogenesis of cotton (LEA D34; Baker JC, Steele C, Dure III (1988) Plant Mol Biol 11: 227-291). The mRNAs for ECP31 started to accumulate in zygotic embryos at a late stage of embryogenesis but were undetectable in mature embryos within 24 h after imbibition of seeds. In dry fruits (seeds), the transcripts were detected only in zygotic embryos by in situ hybridization. The level of ECP31 transcripts increased after treatment with abscisic acid (ABA) in torpedo-shaped somatic embryos but not in seven-day-old seedlings. These results suggest that both embryo-specific factor(s) and ABA are involved in the expression of the gene for ECP31.

Abscisic Acid↗

PubMed1992

Effect of nicardipine on haemodynamic response to stress in hypertension.

The effects of the calcium antagonist nicardipine on the pressor response to mental arithmetic, cold pressor and exercise tests have been studied in fifteen patients with established mild to moderate essential hypertension. Nicardipine 20 mg p.o. showed a hypotensive effect within 60 min, associated with a fall in total peripheral resistance and an increase in heart rate. As the pressor response to each stress was not affected by nicardipine, the peak blood pressure reached during each stress was lower. Nicardipine lowers blood pressure at rest as a result of arteriolar dilatation, associated with reflex tachycardia. The pressor responsiveness to various stresses was not affected by nicardipine.

Adult↗

PubMed1992

Effects of enalapril on adriamycin-induced nephrosis.

Adriamycin induces proteinuria and glomerular changes in rats similar to those found in human focal segmental glomerulosclerosis (FSGS). Progression of this lesion may be slowed by use of angiotensin converting enzyme inhibition. To evaluate this we injected two groups of Sprague-Dawley rats with Adriamycin (2 intravenous doses of 2 mg/kg given at an interval of 3 weeks). One group of rats received enalapril (50 mg/l) in their drinking water. Control rats were injected with saline. After 28 weeks, the mean whole kidney glomerular filtration rate was significantly less and proteinuria and sclerotic index were significantly greater in rats receiving adriamycin compared with controls (P < 0.05). Administration of enalapril did not decrease proteinuria (545 +/- 398 mg/day vs 494 +/- 325 mg/day, P >0.05) or improve the glomerular filtration rate (0.31 +/- 0.18 ml/min per g kidney weight vs 0.41 +/- 0.21 ml/min per g, P = 0.27). However, treatment with enalapril significantly reduced the mean glomerular sclerotic index compared with untreated rats (1.62 +/- 0.88 vs 0.82 +/- 0.49, P = 0.05). Enalapril may be beneficial in preserving glomerular structure in this experimental model of FSGS.

Administration, Oral↗

PubMed1992

A case of popliteal cystic degeneration with pathological considerations.

Adventitial cystic degeneration of the popliteal artery is seldom encountered; only 39 cases have been reported up to now in Japan. The pathogenesis of this disease remains controversial, and the authors describe a case in which the pathological findings differed from cases reported in the previous literature. The subject was a 74-year-old man admitted to our hospital complaining of intermittent claudication. The characteristic findings of cystic degeneration of the popliteal artery were uncovered by contrast-enhanced computed tomography (CT) and duplex sonography. The contrast-enhanced CT showed a low-density area and duplex sonography revealed a multi-lobulated low-echoic lesion. The Doppler signal of the low-echoic lesion could not be detected. While some cysts were found in the adventitia, they were mainly located in the media. The media also showed a remarkable decrease of smooth muscle cells and a prominent mucinous degeneration that had occurred circumferentially. These findings suggest that the medial degeneration noted had occurred prior to cystic formation. Because of this and other findings, we recommend the use of the term cystic degeneration of the popliteal artery in addition to the term cystic adventitial disease of the popliteal artery.

Aged↗

PubMed1992

Transitional cell carcinoma of bladder in thirteen-year-old boy.

We report a rare case of primary epithelial bladder tumor in a thirteen-year-old boy. Histologically, the tumor was that of a solitary and papillary transitional cell carcinoma, grade 1. This tumor was detectable at cystoscopic examination, and cytologic procedures were without benefit for a diagnosis.

Adolescent↗

PubMed1992

Elevated content and secretion of gut GLI in VMH-lesioned rats.

Gut glucagon-like immunoreactivity (GLI), a supposed intestinal growth factor in the plasma and gastrointestinal tract, and weight of the gastrointestinal tract, an intestinal growth indicator, were examined in ventromedial hypothalamic (VMH)-lesioned rats 1 week after VMH lesions. Postprandial plasma gut GLI in VMH-lesioned rats was significantly higher than that in control rats. The content of gut GLI in all gastrointestinal sections except the duodenum in VMH-lesioned rats was significantly greater than that in control rats. Gel chromatography in the lower portion of the small intestine in which GLI content was the highest of all sections revealed the same pattern in both VMH-lesioned and control rats with two peaks of similar molecular size. Weight of all gastrointestinal sections except the cecum in VMH-lesioned rats significantly increased. These results demonstrated that both gut GLI secretion and production were enhanced in VMH-lesioned rats. The elevated gut GLI release may accelerate growth of the gastrointestinal tract in these animals.

Animals↗

PubMed1992

The temporal relationship between the onset of rapid eye movement period and the first micturition thereafter in the human fetus with advance in gestation.

The objective of this study was to investigate whether micturition occurs, temporally related to the onset of the rapid eye movement (REM) period, in the human fetus. The study was made on 139 fetuses at 33-36 weeks and 153 at 37-41 weeks gestation. The discrepancies between the expected (F(exp)) and observed (F(obs)) frequencies of time lag between the onset of the REM period and the first micturition thereafter were assessed using the goodness-of-fit test. At 33-36 weeks gestation, there was no statistical difference between F(obs) and F(exp) (P greater than 0.05). At 37 weeks onwards, however, significant differences were noted between F(obs) and F(exp) (P less than 0.005). Seventy-two percent of all micturitions occurred within eight minutes after the onset of the REM period. This indicates that there is a temporal relationship between the onset of the REM period and the first micturition thereafter, at term, during 37-41 weeks of gestation.

Embryonic and Fetal Development↗

PubMed1992

Studies on the afferent and efferent renal nerves following autotransplantation of the canine kidney.

The presence of both afferent and efferent renal nerves following renal transplantation was investigated in a canine autotransplant model. The efferent postganglionic sympathetic renal nerves were studied using the glyoxylic acid histofluorescence technique to identify renal tissue adrenergic amines (Grade 0-4). The afferent sensory renal nerves were studied by the systemic blood pressure response to renal arterial injection of capsaicin. In 8 control dogs with native innervated kidneys (Group I), intrarenal injection of capsaicin significantly increased the systemic blood pressure from baseline by 32.4 +/- 6.3 mm. Hg (p less than 0.01). This response was equivalent to the blood pressure increase following injection of capsaicin into the mesenteric artery which was 37.3 +/- 9.8 mm. Hg. The renal tissue histofluorescence grade in this group was 4. Six dogs were studied two to three weeks after autotransplantation of a solitary kidney (Group II). Intrarenal injection of capsaicin did not increase the systemic blood pressure in these animals. Three dogs in this group had no evidence of renal tissue adrenergic amines by histofluorescence (Grade 0); the remaining two animals had renal tissue histofluorescence grades of 1 and 2. Eight dogs were studied 12 to 35 months after autotransplantation of a solitary kidney (Group III). Intrarenal injection of capsaicin in these animals significantly increased the systemic blood pressure from baseline by 10 +/- 1.4 mm. Hg (p less than 0.001). The renal tissue histofluorescence grade in this group ranged from 1 to 3. These data support the presence of both afferent and efferent renal nerves in the kidney at greater than or equal to one year post-transplant.

Animals↗

PubMed1992

Prospective study of laparoscopic cholecystectomy in two hundred and fifty patients.

Two hundred and fifty consecutive patients (151 women, 99 men, age 49.3 years) with symptomatic gallstones as diagnosed on ultrasonography underwent elective laparoscopic cholecystectomy over a 12-month period. Preoperative intravenous cholangiography (IVC) and endoscopic retrograde cholangiography (ERC) were also performed in 203 and 200 patients, respectively. Laparoscopic cholecystectomy was successfully performed on 248 of the 250 patients (99.2%). Two patients required conversion to open cholecystectomy because of a pin hole injury to the portal vein in one case, and because of technical difficulties with the dissection due to severe adhesions in the other patient. Procedure time in the initial 100 cases decreased from an average of 216 minutes for the first ten cases to 87 minutes for the last 30 cases, including the time required for intraoperative cholangiography (IOC). Bile duct stones were found in 4 cases on IOC which were diagnosed by preoperative ultrasonography, IVC and ERC in 0, 2 and 3 cases respectively. An intraabdominal drain was inserted for two days in all cases. The mean hospital stay was 8.6 days (range 4 to 19 days) with no readmissions. No complications were seen at short-term follow-up one month after discharge. Although there was a significant learning period, the procedure was safe and effective and could be performed with minimal risk. The results show that physicians with experience in both endoscopy and laparoscopy are well qualified to perform laparoscopic cholecystectomy after appropriate training.

Cholangiography↗

PubMed1992

Preliminary experience using laparoscopic transcystic cholangioscopy for treatment of common bile duct stones.

Laparoscopic transcystic cholangioscopy (LTC) in combination with electrohydraulic lithotripsy may be an alternative treatment to ERCP and sphincterotomy in patients with both gallbladder and common bile duct stones undergoing laparoscopic cholecystectomy. Preliminary experience using LTC lithotripsy in 13 cases is reported. In 12 cases the stones were pushed out into the duodenum using the tip of the cholangioscope, in 8 of them stone disintegration via LTC lithotripsy also being required. In the remaining case the cholangioscope could not be inserted into the common bile duct via the cystic duct due to complete cystic duct obstruction. The average hospital stay was 9 days (range 6-16) in patients with LTC/lithotripsy, which did not differ significantly from 8.4 days (range, 4-19) (n = 330) in the group undergoing laparoscopic cholecystectomy alone. The patients usually resumed normal activity the day after discharge. LTC lithotripsy has the advantages over endoscopic sphincterotomy of a shorter treatment and preservation of a normal functioning sphincter of Oddi. Further technical improvements, especially the development of a cholangioscope for this purpose, are urgently required.

Adult↗

PubMed1992

Clinical and basic aspects of an anorexiant, mazindol, as an antiobesity agent in Japan.

The Japanese Mazindol study group investigated the action of an anorexiant, mazindol, and found that it reduced food intake by directly suppressing neurons in the lateral hypothalamus, inhibited gastric acid secretion, increased motor activity, decreased glucose absorption, and inhibited insulin secretion. It thus appears that the main effect of mazindol is to decrease food intake through suppressing feeding centers in the hypothalamus. A multicenter open study of mazindol in Japan revealed that loss of body weight and relative body weight in 14 wk were 4.6 kg and 9.2%, respectively, with suppression of appetite in the majority of obese patients. A multicenter double-blind study demonstrated that mazindol was superior to the placebo in the treatment of simple obesity. We also suggest that mazindol is effective in the maintenance of reduced body weight after obesity therapy and in the treatment of obesity-related diseases such as diabetes, hypertension, or hyperlipidemia.

Animals↗