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Biomedical subjects

M Satoh

Publications and source records attributed to M Satoh.

At least 973 records · Page 54Linked to original sources
PubMed1987

Subconvulsive doses of intracisternal bicuculline methiodide, a GABAA receptor antagonist, produce potent analgesia as measured in the tail pinch test in mice.

Bicuculline methiodide, a GABAA antagonist produced potent analgesia in the tail pinch test when it was given intracisternally (i.c.) but not intrathecally (i.t.). The ED50 was 5 ng/mouse. This analgesia was antagonized by i.c. muscimol, a GABAA agonist. On the contrary, muscimol (i.t.) produced bicuculline-reversible analgesia. These findings suggest that brain GABA may transmit the nociceptive information while GABA in the spinal cord may inhibit it.

Analgesics↗
PubMed1987

Release of substance P from the spinal dorsal horn is enhanced in polyarthritic rats.

Using in situ spinal dorsal horn perfusing method in decerebrated rats, we measured the release of immunoreactive substance P (iSP) in polyarthritic rats. The spontaneous release of iSP from the dorsal horn in the polyarthritic rats was significantly accelerated over that in control non-inflamed rats. Passive movements of the inflamed ankle joint evoked a significant increase in the release of iSP, while a similar movement of the non-inflamed joint led to no such increase. These results suggest that the facilitated release of iSP from the primary afferent terminals in the spinal dorsal horn in polyarthritic rats possibly plays a role in transmission of chronic pain of inflamed joints.

Animals↗
PubMed1987

Calcitonin gene-related peptide promotes mechanical nociception by potentiating release of substance P from the spinal dorsal horn in rats.

In vitro superfusion with capsaicin (5 X 10(-7) M) of slices of the dorsal half of the rat spinal cord produced a significant increase in a release of immunoreactive substance P (iSP). Calcitonin gene-related peptide (CGRP: 10(-6) M) significantly potentiated the capsaicin-induced release of iSP. On the other hand, when CGRP (5 nmol/rat) was intrathecally injected, the peptide produced a significant hyperalgesia to mechanical noxious stimuli (pinching the hind paw), but aversive responses and potentiation of substance P-induced aversive responses were never observed. These findings suggest that in the rat spinal dorsal horn, CGRP potentiates the release of substance P from the primary afferent terminal and promotes the transmission of nociceptive information induced by mechanical noxious stimuli.

Animals↗
PubMed1987

Prevention of lethal and renal toxicity of cis-diamminedichloroplatinum(II) by induction of metallothionein synthesis without compromising its antitumor activity in mice.

The participation of renal metallothionein (MT) in the toxicity and antitumor activity of cis-diamminedichloroplatinum(II) (cis-DDP) in male mice was examined. Preinduction of MT in the kidney by the s.c. administration of bismuth compounds decreased the lethality and renal and gastrointestinal toxicity caused by a single s.c. injection of cis-DDP. In the present study a correlation between the protective effect of pretreatment with bismuth nitrate against cis-DDP toxicity and the preinduced MT levels in the kidney was observed. Bismuth nitrate pretreatment showed no effect on the antitumor activity of cis-DDP against several transplantable tumors, probably because it induces MT in the kidney but not in tumor tissues. The fact that p.o. preadministration of bismuth subnitrate, an antidiarrheal drug, also depressed the lethal toxicity of cis-DDP is promising for its prompt application in medical attention. Thus, bismuth pretreatment allows higher doses of cis-DDP with no apparent toxicity, resulting in more efficient utilization of this anticancer drug.

Animals↗
PubMed1987

Induction of renal metallothionein allows increasing dose of an extensively used antitumor drug, cis-diamminedichloroplatinum.

The effect of preadministration of bismuth, a specific potent inducer of renal metallothionein (MT), on the lethal and renal toxicity of cis-DDP, an extensively used antitumor drug containing heavy metal platinum, in mice was investigated. Pretreatment of mice with two s.c. doses of bismuth nitrate (BN; 30 mumol/kg/day) at 24-hr interval prevented the lethal toxicity, the increase in BUN value and the occurrence of diarrhea caused by cis-DDP (35 mumol/kg, s.c.). This protective effect of BN-pretreatment was significantly correlated with increased MT levels in the kidney. The pretreatment of tumor-bearing mice with BN also depressed the lethal and renal toxicity of cis-DDP without compromising its antitumor activity, and allowed the administration of relatively high dose of cis-DDP. Daily five consecutive p.o. preadministration of bismuth subnitrate (BSN), one of the bismuth compounds being in use as a protectant of the gastrointestinal lining, was also effective to depress the lethal toxicity of cis-DDP. Since the effective dose of BSN is not far from that commonly used for men, this treatment will allow the increase in cis-DDP dose, promising a clinical advantage in cancer chemotherapy.

Adenocarcinoma↗
PubMed1987

Alteration of hepatic phospholipids in rats and mice by feeding di-(2-ethylhexyl)adipate and di-(2-ethylhexyl)phthalate.

Effects of di-(2-ethylhexyl)adipate (DOA) and di-(2-ethylhexyl)phthalate (DEHP), plasticizers for polyvinylchloride products, on concentrations and compositions of hepatic phospholipids were studied in rats. When administered to rats at a 2% level for 2 wk, both DOA and DEHP caused a hepatomegaly, an increase in hepatic phospholipids and a decrease an increase in hepatic phospholipids and a decrease in the ratio of phosphatidylcholine (PC) to phosphatidylethanolamine (PE). In the comparable study with mice, the alkyl moiety of DOA was found to be responsible for these alterations. DOA and DEHP specifically altered fatty acid compositions of PC and PE: there was an increase in oleic and palmitic acids and a decrease in stearic and docosahexaenoic acids in PC and an increase in arachidonic acid at the expense of docosahexaenoic acid in PE. In addition, DOA caused an increase in the trienoic and tetraenoic molecular species in PC and an increase in the 1-palmitoyl-2-arachidonyl (16:0@20:4) species in PE. Thus, the effects of DOA on the lipid dynamics resembled those observed with DEHP, although the magnitude was slightly moderated.

Adipates↗
PubMed1987

Melanocyte-stimulating hormone affects melanogenic differentiation of quail neural crest cells in vitro.

Quail neural crest cells were treated in vitro with alpha-melanocyte-stimulating hormone (alpha-MSH) or dibutyryl cyclic AMP (dbcAMP) plus theophylline. These treatments increased the proportion of melanocytes to total cells in crest cell outgrowth cultures. Pigmentation of neural crest cell clusters proceeded more rapidly when cultures were treated with alpha-MSH or dbcAMP plus theophylline than when untreated. In clonal cell cultures, the proportion of pigmented colonies to total colonies was increased by MSH treatment. From these results, MSH seems not only to accelerate melanogenic differentiation but also to affect the state of commitment of neural crest cells to melanogenic differentiation in vitro, and this action of MSH appears to be mediated by cAMP.

Animals↗
PubMed1987

Deficiency of selenium intake enhances manifestation of renal toxicity of cis-diamminedichloroplatinum in mice.

The effect of the dietary level of selenium on lethal and renal toxicity of cis-diamminedichloroplatinum (cis-DDP) was investigated using mice fed diets containing 4 different concentrations of selenium (0.009, 0.1, 0.4 or 1.0 ppm) for 6 weeks starting at 4 weeks of age. The groups of mice fed the diets containing 0.009 and 0.1 ppm of selenium showed higher sensitivity to the lethal toxicity caused by a single subcutaneous administration of cis-DDP (32 mumol/kg) than the other groups. The renal toxicity of cis-DDP, indicated by increases in blood urea nitrogen (BUN), serum creatinine and urinary activity of N-acetylglucosaminidase (NAG), was significantly enhanced by a decrease in dietary selenium level. These results suggest that the dietary level of selenium affects the manifestation of lethal and renal toxicity of cis-DDP.

Acetylglucosaminidase↗
PubMed1987

Anesthetic management in the arterial switch "jatene" operation for transposition of the great arteries.

The arterial switch "Jatene" operation for transposition of the great arteries (TGA) is an anatomic reconstruction at the level of the great arteries with reimplantation of the coronary arteries. The anesthetic management of 46 patients who underwent the Jatene operation between 1982 and 1985 was retrospectively reviewed. The mean age was 12.3 +/- 11.2 months (youngest: 4 days) and the mean body weight was 7.0 +/- 2.8 kg (smallest: 3.0 kg). Anesthesia was induced with ketamine in 35 patients, and maintained with morphine in 36 patients. Catecholamine (CA) drugs were given to 10 patients before cardiopulmonary bypass (CPB) and to all patients after CPB. In addition, nitroglycerin (NTG) was given to 13 patients during and after CPB. Platelets were given to prevent bleeding due to platelet damage caused by CPB. Six patients died, producing a mortality rate of 13%. Body weight, age, anesthetic agent, dose of CA, volume of blood loss, and duration of aortic cross-clamping, anesthesia, and operation were not significantly related to the deaths. Urinary output was significantly smaller (P < .05) in the patients who died. The LV/RV pressure ratio was as low as 0.625 and 0.645 in two of six deaths due to left ventricular hypoplasia. Severe pulmonary hypertension occurred in the postoperative period in two patients, and two patients had heart failure following a previous operation for coarctation or interruption of the aorta. Since hypotension during induction is detrimental in these cases, ketamine was commonly used as an induction agent. Morphine was chosen rather than fentanyl to avoid bradycardia. Administration of CA drugs produced an inotropic effect on the heart, and NTG helped maintain coronary blood flow and prevented pulmonary hypertension. There were no anesthetic deaths as judged by both the surgeons and anesthesiologists.

Adjuvants, Anesthesia↗
PubMed1987

Benign schwannoma of the pterygopalatine fossa with intracranial extension: a case report.

The authors present a rare case of benign schwannoma arising in the pterygopalatine fossa. The patient, an 18-year-old female, initially noticed blurring of her left eye but later, sudden loss of her left vision occurred. Radiological and computed tomographic studies outlined a mass occupying the left pterygopalatine fossa, which extended into the middle cranial fossa, the maxillary, ethmoid and sphenoid sinuses and the orbit. The histology of a transantral biopsy was reported as a benign schwannoma. The tumor was successfully removed by a transmaxillary approach. The eye symptoms disappeared four weeks following surgery. The nerve of origin of the tumor was not identified. The authors posturate that erosion of the skull base with mild to moderate extension into the middle cranial fossa, does not appear to be a contraindication for excising a schwannoma by the transmaxillary approach in this area.

Adolescent↗
PubMed1987

Glucocorticoid-induced growth inhibition of human neoplastic salivary gland duct cell line (HSG).

The purpose of this study was to examine the effect of glucocorticoid on human neoplastic salivary duct epithelial cell line (HSG). Dexamethasone was found to inhibit cell growth and to increase cell size and the ratio of protein content to DNA content in a cell. The inhibition of cell growth was dose-dependent; in comparison to the control (33.8 +/- 3.1 h), the population doubling time was 1.57-fold longer in 10(-5) M dexamethasone (P less than 0.01, N-K test). [3H] thymidine incorporation was inhibited in 45.5% of the control at 10(-5) M. Plating efficiency was 20.5 +/- 3.0% in 10(-5) M and 47.0 +/- 4.4% in the absence of dexamethasone. Cell diameters increased 1.29 fold in 10(-5) M dexamethasone in comparison to the control size (16.0 +/- 2.1 micron). The ratio of total protein content of DNA content increased 1.46 fold in 10(-5) M dexamethasone-treated cells on the seventh day of cultivation. Scatchard plot analysis using [6, 7-3H]-triamcinolone revealed that the HSG cells had apparent cytosolic glucocorticoid receptors with an equilibrium dissociation constant (Kd value) of 6.48 nM, whose number of binding sites (NBS) was 57.8 fmol/mg protein.

Cell Division↗
PubMed1987

Possible mechanism involved in the inhibitory action of U-50, 488H, an opioid kappa agonist, on guinea pig hippocampal CA3 pyramidal neurons in vitro.

Intracellular recordings of the CA3 pyramidal neurons in the guinea pig hippocampus were made in vitro. U-50 488H (100 microM), a selective opioid kappa agonist, decreased the synaptic response produced by stimulation of the mossy fibers but did not affect the membrane potential, the input resistance and the generation of the Na+ spikes or the Ca2+ spikes. Iontophoretically applied U-50 488H depressed the depolarization produced by L-glutamate. U-50 488H (100 microM) also depressed the consistent depolarization produced by veratrine (3 X 10(-5) g/ml) and this effect was partially antagonized by naloxone. Moreover, application of U-50 488H led to a disappearance of the anomalous rectification. These results suggest that U-50 488H depresses the synaptic activities of the CA3 pyramidal neurons by inhibiting a subtype of the Na+ channel, "Na+ channel type II" which slowly closes, of the soma and/or the dendrites of the neurons.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1987

Glycoprotein receptors to wheat germ agglutinin on the surface of murine macrophages.

Peritoneal macrophages elicited in various ways exhibited marked wheat germ agglutinin (WGA)-dependent cytolytic activity against MM46 cells [nearly 100% lysis at effector to target ratio (E/T) = 40], while macrophage cell lines J774.1 and WEHI-3 cells showed less activity (-25% at E/T = 0.63-2.5) and no cytolysis (E/T = 40), respectively. Studies on the kinetics of WGA-binding showed that peritoneal macrophages had an association constant (Ka) of 0.09-0.18 X 10(6) M-1 and the number of their binding sites (N) was 2-7.7 X 10(7)/cell, while the Ka and N values of J774.1 and WEHI-3 cells were 1.2 X 10(6) M-1 and 4.1 X 10(7)/cell and 0.6 X 10(6) M-1 and 5.4 X 10(7)/cell, respectively. On the other hand, cytolytic target MM46 cells showed values of 0.27 X 10(6) M-1 and 1.8 X 10(8)/cell. Lower affinities and moderate numbers of binding sites coincided with the efficient WGA-dependent cytolytic activities of the effector cells. The surface of peritoneal macrophages and J774.1 and MM46 cells was iodinated, the cells lysed, the lysates fractionated on a WGA-Sepharose column and the WGA-binding surface-glycoproteins in GlcNAc-specific fractions of the eluate were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Peritoneal macrophages gave three major bands of 153 kilo dalton (kDa), 140 and 90 kDa proteins, whereas J774.1 and MM46 cells both gave 6 bands of very similar molecular weights and intensities that were quite unlike those of peritoneal macrophages.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗