Search PubMed⌕ Search

Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 937 records · Page 52Linked to original sources
PubMed1981

Selective determination of elemental mercury in blood and urine exposed to mercury vapor in vitro.

A method is described to ensure quantitative measurement of dissolved mercury vapor (Hg0) in blood and urine. Room air passed through samples of blood and urine carries with it all the dissolved Hg0 but leaves behind all the ionic mercury (Hg++). Oxidation of Hg0 to Hg++ in blood samples is completely inhibited by addition of ethanol (0.5% v/v). To minimize error due to evaporation of Hg0, it is suggested that samples should be stored at 0 degree C and Hg0 should be determined within 60 min of collection of blood samples and within 10 min of urine samples.

Ethanol↗
PubMed1981

Role of gastric acid and prostaglandins in the formation of gastric antral ulcers produced by indomethacin in the rat.

Indomethacin produces gastric corpus erosions in the fasted rat and antral ulcers in the refed rat. The purpose of this study was to determined the role of gastric acid and prostaglandins in the formation of these gastric lesions. Sprague-Dawley rats, 180-250 g, were fasted for 24 hr (fasted) or fed chow pellets for 1 hr after a 24 hr fast (refed). Thirty mg/kg indomethacin was administered s.c. after a 24 hr fast or 0.5 hr after the refeeding, and 6 hr later the animals were sacrificed. Cimetidine, in antisecretory doses, prevented the formation of corpus erosions in a dose dependent manner but only the largest dose of cimetidine, 100 mg/kg s.c. x 2, prevented the antral ulcer formation. Prostaglandin E2, in non-antisecretory doses, prevented both the corpus erosions and antral ulcers in a dose dependent manner. We conclude that: 1. Antral ulcer formation is less sensitive to cimetidine than corpus erosion formation. This suggests that either acid plays a minor role in antral ulcer formation or more cimetidine is required for acid inhibition in the refed rat. 2. A deficiency of endogenous prostaglandins is an essential factor in the formation of indomethacin-induced gastric lesions. However, an additional mechanism is needed to explain the variation in location and histology of lesions with different feeding conditions.

Animals↗
PubMed1981

Influence of angiotensins (I, II & III) on prostaglandin production by minced rat renal medulla.

Minced rat renal medulla was incubated for 30 min at 37 degrees C in the presence of angiotensin I, II or III (100 ng/ml) to determine the existence of a direct stimulating effect on prostaglandin (PG) production. PGE2, PGF2 alpha, 6-keto PGF1 alpha and Thromboxane B2 (TXB2) were determined by radioimmunoassay. For analysis of data variance, the results were separated according to whether the net output of PGE2 was above or below 1.5 ng PGE2 equivalent/mg tissue/30 min. Under low-output conditions, angiotensin I, II or III stimulated PGE2 production significantly (p less than 0.02) and tended to augment PGF2 alpha production, while under high-output conditions no effect on PGE2 or PGF2 alpha production was observed. Under either output condition, angiotensin I, II or III had no effect on 6-keto PGF1 alpha and TXB2.

Alprostadil↗
PubMed1981

Surgical treatment of anomalous origin of the left coronary artery from the pulmonary artery associated with tetralogy of Fallot.

An 8-year-old boy with anomalous origin of the left coronary artery from the pulmonary artery associated with tetralogy of Fallot, which was definitely diagnosed preoperatively, was operated on with success. Direct implantation of the left coronary artery into the aorta following division of the left coronary artery from the pulmonary artery and, concomitantly, total repair for tetralogy of Fallot using an external valved conduit were performed. Postoperative cineangiogram revealed a hemodynamically well-repaired intracardiac condition and anterograde filling of the left coronary artery, compared with retrograde left coronary flow from intercoronary collateral vessels preoperatively. To the best of our knowledge, there is not a previously published report of anomalous origin of the left coronary artery from the pulmonary artery associated with tetralogy of Fallot that was treated surgically with success.

Aortography↗
PubMed1981

Effects of sodium selenite on distribution and placental transfer of mercuric mercury in mice of late gestational period.

Mercury distribution and placental transfer in mice were investigated with coadministration of selenite. Pregnant mice, subcutaneously injected with 1.5 or 15.0 mumol/kg of mercuric chloride and 0, 1.3, 12.7 or 25.3 mumol/kg of sodium selenite on day 16 or their gestation, were examined for tissue distribution of mercury 24 hours after treatment. Elevated mercury concentrations in the blood were found along with increasing doses of selenite at the two dose-levels of mercury, on the other hand, decreased accumulation of mercury with increased doses of selenite was found in the kidneys and brain. In the liver, the largest amount of mercury was accumulated by approximate-equimolar combinations of doses. The amount of mercury transferred to the fetus was remarkably reduced in the groups injected with 12.7 mumol/kg of selenite at the two dose-levels of mercury. In the groups injected with higher dose of mercury, where fetal organs were measurable for mercury, fetal brain, liver or kidneys of the group of selenite 12.7 mumol/kg contained the least amount of mercury among the groups. All of the mice injected with 15.0 mumol/kg of mercury and 25.3 mumol/kg of selenite aborted before sacrifice.

Amnion↗
PubMed1981

Comparison of the chronotropic responses to local anesthetics (procaine, lidocaine, prilocaine, mepivacaine and bupivacaine) of the canine sinus node in situ.

Effects of local anesthetics (procaine, lidocaine, prilocaine, mepivacaine and bupivacaine) on the sinus node of the nerve-intact dog heart were studied in situ by means of selective perfusion of the sinus node through the sinus node artery. The agents caused a dose-dependent decrease in heart rate and the order of their potency in decreasing the heart rate was as follows, bupivacaine greater than lidocaine=mepivacaine=prilocaine greater than procaine. The decrease in heart rate produced by these local anesthetics was not affected by prior administration of atropine. With procaine and prilocaine, the decrease in heart rate was followed by an increase which was inhibited by propranolol given into the sinus node artery or was suppressed in reserpine-pretreated dogs. Tetrodotoxin also prevented the positive chronotropic effect of procaine. From these results the following conclusion can be drawn: the negative chronotropic effects of these agents are induced mainly by a direct inhibitory action on the sinus node, and partly by blockade of sympathetic tone, and the interaction with the postganglionic adrenergic nerves plays an important role in the induction of the positive chronotropic responses to procaine and prilocaine.

Anesthetics, Local↗
PubMed1981

Changes in ingestive behavior, serum glucose and free fatty acids concentrations in rats following intracerebroventricular injection of spermine.

We examined the changes in ingestive behavior, serum glucose (Glc) and free fatty acids (FFA) concentrations in male rats following intracerebroventricular (i.c.v.) injection of spermine (SPM). In satiated rats, over a 53.3 nmol of SPM suppressed feeding and drinking behavior in a dose-dependent manner. The median suppressive dose was 90.8 nmol for feeding behavior and 68.3 nmol for drinking behavior. Spermidine also suppressed ingestive behavior but the potency was appreciable weak compared to that of SPM, and the occurrence of the maximal suppression was observed 2-3 days later than that of SPM. The most significant anorexia and adipsia induced by SPM appeared between 16 and 36 hr after i.c.v. administration. SPM (180 nmol) produced a biphasic increase in serum Glc concentration. The 1st peak was at 1 hr and the other peak was 24 hr after the dosing. The same dose of SPM elevated serum FFA concentrations gradually, and the maximal increase appeared 24 hr after the injection. As less than a 120 nmol dose of SPM did not alter serum Glc and FFA concentrations, there seems to be no causal relation between SPM-induced anorexia, and changes in serum Glc and FFA concentrations. Nevertheless, the findings that a very small dose of SPM produced anorexia and adipsia support the possibility that SPM may play some functional role in the brain.

Animals↗
PubMed1981

Effect of lidocaine and procaine on the action potential of canine sinus nodal cells.

Effects of local anesthetics (lidocaine and procaine) on the canine sinus node were studied using isolated right atrial preparations which were obtained from puppies adn perfused with oxygenated Tyrode solution through the dorsal right atrial artery. Action potential of the sinus nodal area which was characterized by the slow rate of phase O and diastolic depolarization, was recorded using the conventional microelectrode technique, simultaneously with atrial contraction. Lidocaine (10-300 micrograms) prolonged the cycle length and duration of action potential, decreased the rate of phase 4 depolarization and amplitude of action potential, and shifted the threshold potential and maximal diastolic potential to the depolarizing direction. The atrial contraction decreased simultaneously. In higher doses, sinoatrial block was occasionally observed in 8 of 55 experiments. Procaine (10-300 micrograms) had similar negative chronotropic and inotropic effects and induced sinoatrial block in 7 of 57 experiments, but unlike lidocaine, procaine produced positive chronotropic and inotropic effects following the initial negative responses in 16 of 57 experiments. The sinus node acceleration was accompanied by an increase in the rate of phase 4 depolarization. Chronotropic changes of the sinus nodal cells by these drugs were accompanied by the changes in both the rate of phase 4 depolarization and duration of the action potential.

Action Potentials↗
PubMed1981

Indomethacin produces gastric antral ulcers in the refed rat.

Indomethacin produces gastric corpus erosions in the fasted rat and small intestinal ulcers in the conventionally fed rat. We found that in rats fed chow pellets for 1 h after a 24-h fast, indomethacin given within 2 h after refeeding produced lesions in the gastric antrum, primarily along the lesser curvature, and also in the small intestine. The antral lesions reached a maximum size in 6-10 h, penetrated the muscularis mucosae within 3 days, and did not diminish for at least 7 days. The formation of the antral ulcer was prevented by prostaglandins or adrenalectomy, but was not affected by cimetidine, atropine, and/or vagotomy. In contrast, the gastric corpus erosions produced by indomethacin in the fasted rat were prevented by antisecretory drugs or vagotomy, and were aggravated by adrenalectomy. It is concluded that: (a) the chronic antral ulcers produced by indomethacin in a refed rat mimic human gastric ulcer with regard to location and histology; and (b) the mechanism of antral ulcer formation is different from corpus erosion formation, in that it was resistant to antisecretory drugs and vagotomy and was prevented by adrenalectomy. This experimental ulcer model could prove useful for studies of the etiology and therapy of gastric ulcer disease.

Adrenalectomy↗
PubMed1981

The effect of longitudinal tension on the amplitude of the contraction rhythm of plasmodial strands of Physarum polycephalum.

Plasmodial strands of Physarum polycephalum exhibit a characteristic contraction rhythm. The amplitude of the isotonic tension increased linearly with the cube root of relative stress. The period of the isometric tension increased linearly with the amplitude of the oscillation, but stayed constant above a critical value. The above empirical formulae were found applicable for all temperatures employed, 9 to 28 degrees C, but different temperature coefficients were observed below and above 15 to 16 degrees C.

Cytoplasm↗
PubMed1981

[Effects of intraperitoneally administered spermine on ingestive behavior, serum glucose and free fatty acids concentrations in rats (author's transl)].

The intraperitoneal administration of spermine (SPM) produced a dual-phasic feeding suppression. The first suppression appeared immediately after the administration and disappeared on the 2nd day. The next suppression was observed on the 3rd day and continued for 2-4 days. The 50% dose which induced suppression on the 3rd day was 64.9 (60.9-69.2) mumol/kg. Drinking behavior was also suppressed on the 1st day, but was facilitated on the 2nd day and lasted for 4-5 days. Serum glucose and free fatty acids concentrations increased after the administration of SPM (80 mumol/kg). Their maximal values obtained at 3 hours after the dosing were 116% and 156% of the control values, respectively. These increases in both substances were not observed in the adrenal-demedullated rats. The same dose of SPM enhanced serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities. The maximal values obtained at 2 hours after the dosing were 264% and 142% of the control values, respectively. On the contrary, serum cholinesterase activity decreased to 44% of the control value at the same hour. These variations of the enzyme activities disappeared at 3 hour, but were again observed between the 1st and 4th days. The results suggest that SPM releases catecholamines from the adrenal medulla, and exerts a toxic action on the liver. The anorexia induced by SPM may be due to these actions on the viscera.

Alanine Transaminase↗
PubMed1980

Conversion of positive to negative chemotaxis by Ca2+ ionophore treatment in plasmodium of Physarum polycephalum.

The plasmodium of Physarum polycephalum was treated with Ca2+ ionophores A23187 or X-537A, and the effects on the chemotactic and contractile activities were studied by applying a double-chamber method and an optical method. (1) At low Ca2+ concentration, attractants (glucose, L-alanine) KH2PO4) remained as attractants and induced a relaxation in the plasmodial strand. Increase in the external Ca2+ level caused a contraction of plasmodium with the same stimuli, and hence converted the attractants to repellents. (2) This phenomenon was specific to Ca2+; Mg2+, Sr2+ or Ba2+ showed no appreciable effects. (3) Repellents (sucrose, KCl, Quinine) induced a contraction, which was not altered by the Ca2+ ionophore treatment. (4) Efflux of Ca2+, which was measured by chemiluminescence of aequorin, increased on glucose reception in the presence of ionophore.

Anti-Bacterial Agents↗