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Biomedical subjects

Y Furuta

Publications and source records attributed to Y Furuta.

At least 217 records · Page 12Linked to original sources
PubMed1980

Electrophysiological effects of lidocaine in sick sinus syndrome.

Electrophysiological studies were performed to see the effects of lidocaine on the conduction system, particularly sinus node and atrium in 40 patients of SSS, using HBE recordings, rapid atrial pacing and atrial extrastimulus technique. Sinus cycle length, PA (P'A), AH, HV intervals, calculated SACT, and refractory periods of atrium, AV node and His-Purkinje system did not change after lidocaine. Only maximum CSRT was significantly increased with lidocaine. These results were not affected by pretreatment of atropine. In conclusion, the combining rapid atrial pacing with lidocaine may be useful to manifest the masked sinus node abnormalities. It was suggested that lidocaine directly depressed sinus node automaticity in SSS patients, without affecting perinodal tissue. Therefore, lidocaine should be used with caution in patients with known or suspected SSS.

Adult↗
PubMed1978

A case report of surgical repair of traumatic rupture of the pericardium and diaphragm.

A 55 year-old male with traumatic rupture of the pericardium, diaphragm and spleen, and with crush of the pancreas was successfully operated upon. The diagnosis of rupture of the diaphragm was done on the chest X ray on admission, and the rupture of the pericardium was diagnosed at the time of laparotomy and thoracotomy. The ruptured spleen and the crushed pancreas tail were removed, and the ruptured pericardium and diaphragm were closed successively.

Accidents, Traffic↗
PubMed1978

beta-Adrenoceptor stimulation of exocrine secretion from the rat pancreas.

1 Effects of catecholamines given intravenously on exocrine secretion from the pancreas were investigated in anaesthetized rats. The flow rate of pancreatic juice under resting conditions was 11.1 +/- 3.2 microliter per hour in 100 animals. 2 Dopamine (0.3--3 mg/kg) and isoprenaline (1--10 microgram/kg) induced almost the same increase in the pancreatic secretion, so that dopamine was 300 times less potent than isoprenaline. The relative potency of the two amines for stimulation of pancreatic secretion was equivalent to that for beta-stimulation of the contractile force of the left ventricle in vivo. 3 Propranolol (0.5 mg/kg) antagonized completely the dopamine- and isoprenaline-induced stimulation of the pancreatic secretion. 4 Haloperidol (10 mg/kg) failed to suppress the secretory effect of dopamine on the exocrine pancreas but abolished the dopamine-induced hypotension. 5 The dopamine-induced secretion was not modified by atropine (3 mg/kg), phenoxybenzamine (3 mg/kg), vagotomy or pithing. 6 Adrenaline and noradrenaline (10 microgram/kg) induced secretion after phenoxybenzamine treatment (3 mg/kg). 7 It is suggested that the rat pancreas has a stimulatory beta-adrenoceptor mechanism of exocrine secretion.

Acetylcholine↗
PubMed1978

[General pharmacological studies on pepleomycin sulfate (NK 631) (author's transl)].

Pharmacological actions of pepleomycin sulfate (NK 631) which is a new antitumor agent derived from bleomycin were studied and the following results were obtained. NK 631 had no significant influences on the central, motor and sensory nervous systems at relatively higher doses (5 approximately 10 mg/kg, i.v., i.p., s.c.). NK 631 (5 approximately 10 mg/kg, i.v.) caused a slight decrease in blood pressure in anesthetized rats and slight increases in blood pressure, heart rate and peripheral blood flow in anesthetized dogs. NK 631 (1 approximately 3 mg) given close-arterially caused a slight increase in the developing tension in the isolated blood-perfused papillary muscle. NK 631 slightly contracted the isolated guinea pig ileum and rat uterus but did not affect the contraction of isolated guinea pig trachea. NK 631 caused significant increases in urine output and Cl excretion in saline loaded rats at 20 mg/kg, i.p. By the local injection of NK 631, a slight edema of rat paw and an increase in rabbit cutaneous permeability were observed. The intraperitoneal injection of NK 631 caused a significant increase in leakage of dye injected intravenously into the peritoneal cavity of mice. NK 631 did not affect hemolysis and prothrombin time at 10(-4) g/ml. In pharmacological actions, significant differences between NK 631 and pepleomycin were not observed.

Analgesics↗
PubMed1977

Studies on sodium and calcium contents of cardiovascular tissue in experimental hypertension.

Sodium and calcium contents of cardiovascular tissue in spontaneously hypertensive rats (SHR) and DOCA hypertensive rats were investigated. The effect of salt loading on these contents of SHR and control Wistar rats was also investigated. Calcium content increased with the development of hypertension, but not sodium content particularly in salt loading rats and at the sustained stage of DOCA hypertensive rats. These results suggest that calcium rather than sodium is more intimately related to the increase in blood pressure.

Animals↗
PubMed1977

Species difference in the secretory response to dopamine in the pancreas of dogs, cats, rabbits and rats.

The effects of dopamine and L-dopa on the exocrine secretion of the pancreas were compared in rats, cats, rabbits and dogs. Dopamine and its precursor, L-dopa, induced a secretin-like stimulation in dogs, while their effects were significantly less in rats. The dopaminergic receptor stimulus was involved in the exocrine secretion of the pancreas in dogs, whereas in rats, the beta-adrenergic receptor was involved. Spontaneous secretion in the resting state was present in rabbits but absent in cats. This spontaneous secretion in rabbits could be definitely inhibited by either dopamine or L-dopa. The secretin-induced secretion in both rabbits and cats was markedly inhibited by either dopamine or L-dopa. Species difference in the secretory response to dopamine in the pancreas of dogs, cats, rabbits and rats may be ascribed to the difference in the incorporation of exogenous L-dopa and dopamine in the exocrine cells of the pancreas.

Animals↗
PubMed1976

[Effects of fusaric acid and its derivative on the cardiovascular system].

The cardiovascular effects of fusaric acid, a dopamine-beta-hydroxylase (DBH) inhibitor and a hypotensive agent, and 5-(4'-chlorobutyl) picolinic acid, one of the most potent DBH inhibitors in fusaric acid derivatives, were investigated in anesthetized dogs. Fusaric acid (10-30 mg/kg) given intravenously caused immediately and dose-dependently a fall in blood pressure, an increase in heart rate, a stimulation of respiration, a marked increase in the rate of superior mesenteric arterial flow, and a decrease in the rate of femoral arterial flow. Fusaric acid (0.3-3 mg) given close-arterially caused a dose-dependent decrease in the sinus rate and in the developed tension in isolated blood-perfused sinoatrial node and papillary muscle preparations, respectively. For the superior mesenteric, renal, and femoral circulations which were perfused with blood, a close-arterial injection of fusaric acid (10-30 mg) increased in the rates of flow in a dose-dependent manner. 5-(4'-Chlorobutyl) picolinic acid showed similar responses as fusaric acid quantitatively or qualitatively. These results indicate that hypotension induced rapidly after intravenous administration of fusaric acid or 5-(4'-chlorobutyl) picolinic acid is not due to the enzyme inhibition, but rather to the direct depression of cardiac function and decrease in peripheral vascular resistance.

Animals↗
PubMed1976

Reversible adrenergic alpha-receptor blocking action of 2,4'-dimethyl-3-piperidino-propiophenone (tolperisone).

The vascular action of 2,4'-dimethyl-3-piperidino-propiophenone hydrochloride (tolperisone hydrochloride), a centrally acting muscle relaxant, was investigated in pentobarbital anesthetized dogs. Tolperisone given intravenously produced a transient hypotension, tachycardia, and hyperventilation. The drug increased the femoral arterial flow, and decreased the superior mesenteric arterial flow following an initial transient increase. When injected directly into femoral and mesenteric arteries, tolperisone caused a rapid increase in both arterial flow (vasodilatation). However, femoral vessels were about 90 times as sensitive as mesenteric vessels to tolperisone. These results indicate that tolperisone shifts the blood volume from mesenteric (visceral) vessels to femoral (skeltal) ones. The femoral vasodilatation produced by i.a. tolperisone was not depressed by the pretreatment with i.a. propranolol, atropine or chlorphenylamine. Tolperisone decreased the contractile force in an isolated and cross-circulated papillary muscle. Tolperisone produced adrenaline reversal and antagonized the pressor response to noradrenaline. Moreover, femoral vasoconstriction caused by i.a. adrenaline was converted to vasodilatation and that caused by i.a. noradrenaline was depressed during an i.a. infusion of tolperisone. These results indicate that tolperisone blocks adrenergic alpha-receptors. The blocking action was rapid in onset, short-lived, and in addition, competitive.

Adrenergic alpha-Antagonists↗
PubMed1975

Enzootic occurrence of chloramphenicol-resistant Salmonella typhimurium var copenhagen in calf population.

Chloramphenicol (CP)-resistant Salmonella typhimurium var copenhagen was frequently isolated (44.1 to 76.7%) from dead, diseased, and healthy calves on 3 farms in 1973 in northern Japan. On 2 of the farms, CP-resistant salmonella appeared suddenly during an epizootic of salmonella infection, and persisted. Of 87 CP-resistant to tetracycline (TC), streptomycin (SM), and sulfonamides (SA), and the remaining 13 isolates from dead calves on a farm were resistant to TC, SM, SA, and kanamycin (KM). Resistance patterns of all CP-resistant isolates were transferred completely.

Animals↗
PubMed1974

Modification by drugs of the secretagogue effect of dopamine on the pancrease.

1 The specific stimulating action of dopamine and L-DOPA on exocrine pancreatic secretion was further investigated in the isolated blood-perfused canine pancreas.2 6-Hydroxydopamine (100 mug, i.a.) stimulated the secretion but was far less potent than dopamine. Epinine (0.3-1 mg. i.a.), alpha-methyldopamine (10-300 mug, i.a.) and octopamine (10-300 mug, i.a.) were ineffective.3 alpha-Methyldopa (30 mg, i.a.) inhibited the stimulating effect of L-DOPA (1-3 mg) on pancreatic secretion.4 Apomorphine (1 mg, i.a.) attenuated dopamine-induced (1-30 mug) pancreatic secretion but did not antagonize secretin-induced (0.03-0.3 units) or pancreozymin-induced (0.3-1 units) secretion.5 These observations suggest that L-DOPA is probably converted to dopamine to stimulate the exocrine pancreas, and that dopamine interacts with the specific receptors.6 The noradrenaline and dopamine content of the canine pancreas was estimated in controls and in dogs treated with secretin, reserpine, L-DOPA or alpha-methyldopa. The values for dopamine and noradrenaline in controls were 139 +/- 6 and 375 +/- 40 ng/g tissue (n=13), respectively. Reserpine reduced the noradrenaline content of the pancreatic tissue without affecting the dopamine content. L-DOPA or secretin caused a significant increase in the dopamine, but not in the noradrenaline content. It is suggested that dopamine has a physiological function in the pancreas which is independent of that of the noradrenaline-containing nerve fibres.

Animals↗