Search PubMed⌕ Search

Biomedical subjects

K Hashiba

Publications and source records attributed to K Hashiba.

At least 109 records · Page 6Linked to original sources
PubMed1986

Sinus node function after selective elimination of sympathetic influences on the sinus node area of the dog.

Six-hydroxydopamine (6OHDA) was injected directly into the subepicardium of the sinus node area in an attempt to damage sympathetic nerve terminals in the sinus node. The changes in sinus node function were observed for 4 weeks. The predominant rhythm was of sinus origin throughout the observation period. The sinus rate progressively decreased from 145.1 +/- 14.2 to 76.2 +/- 12.1 beats/min during the first week after injection of 6OHDA. The sinus rate remained at this level for 2 weeks, followed by a gradual increase to 89.3 +/- 18.2 beats/min 4 weeks after injection of 6OHDA. These sinus rates were only significantly different from control dogs through the 14th postoperative day. The sinus rate was considerably increased by intravenous atropine injections 5 to 7 days after the injection of 6OHDA into the sinus node area. The sinus node recovery time was much longer in dogs with an injection of 6OHDA than that in the control dogs throughout the observed period. These results suggest that elimination of the sympathetic influences on the sinus node can be achieved by direct injection of 6OHDA into the sinus node area in the dog, and that sinus node function can be depressed by decreasing sympathetic tone alone, in the absence of an intrinsic dysfunction of the sinus node.

Animals↗
PubMed1986

The role of renal kallikrein and prostaglandin in the control of renin release.

Renal prostaglandins and kallikrein are considered to play an important role in the control of renin release. Recently, we have shown that aprotinin, a kallikrein inhibitor, inhibits the stimulation of plasma renin activity (PRA) by either furosemide or a low sodium diet. However, the mechanisms of action of kallikrein are unknown. Since kallikrein may stimulate bradykinin and prostaglandin production, the present study examines the relationship of renal kallikrein and renal prostaglandins in the control of renin release. Furosemide and a low sodium diet stimulated PRA, urinary kallikrein excretion and urinary prostaglandin E2 excretion. Aprotinin and indomethacin inhibited both furosemide and low sodium diet stimulation of PRA. When maximum doses of both aprotinin and indomethacin were given, PRA was more strongly suppressed than by indomethacin alone. The stimulation of urinary kallikrein excretion by furosemide and by a low sodium diet was not inhibited by indomethacin. These results suggest that both renal kallikrein and prostaglandins play an important role in the control of renin release under sodium depletion. Renal kallikrein may also have a direct action on the kidney to release renin.

Animals↗
PubMed1986

Abnormality of circulatory reflex and aldosterone response during head-up tilting in patients with primary aldosteronism.

Abnormality of the circulatory reflexes has been reported in patients with primary aldosteronism. However, changes in blood pressure, heart rate, plasma renin activity (PRA), and plasma aldosterone concentration (PAC) after head-up tilting in primary aldosteronism have not yet been reported. Seven patients with primary aldosteronism were tilted to a 65 degree head-up position which was maintained for 30 min. Systolic blood pressure decreased significantly 5 min after tilting and remained at this level during the period of tilting. Diastolic blood pressure did not change during the tilting. Heart rate increased after 5 min of tilting and this level of heart rate was maintained for 30 min. Plasma renin activity was low and did not change during tilting. However, plasma aldosterone concentration increased significantly 20 min after tilting. Plasma cortisol concentration and plasma ACTH concentration also increased significantly. These results suggest that primary aldosteronism causes abnormalities of the circulatory reflexes. The increase of endogenous ACTH may increase plasma aldosterone concentration in patients with primary aldosteronism.

Adrenocorticotropic Hormone↗
PubMed1986

The mechanism of the control of renin release by beta-adrenergic receptors.

Recent reports suggest that prostaglandins play an important role in the beta-adrenergic receptor mechanism of renin release. However, the site of the action of prostaglandins has not yet been clarified. Superfusion of rabbit renal cortical slices was used to evaluate the beta-adrenergic receptor mechanism of renin release. Renin release was stimulated by isoproterenol, prostaglandin E2, and dibutyryl cyclic AMP. Renin release stimulated by isoproterenol was inhibited by propranolol, whereas renin release stimulated by prostaglandin E2 was not inhibited by propranolol. Isoproterenol stimulated prostaglandin E2 release as well as renin release, and indomethacin inhibited these effects of isoproterenol. Propranolol inhibited prostaglandin E2 release stimulated by isoproterenol. On the other hand, indomethacin did not affect renin release stimulated by prostaglandin E2 release. Dibutyryl cyclic AMP did not stimulate prostaglandin E2 release. Indomethacin did not affect renin release stimulated by dibutyryl cyclic AMP, however, it suppressed prostaglandin E2 release during the superfusion with dibutyryl cyclic AMP. Finally, isoproterenol and prostaglandin E2 stimulated cyclic AMP release. These data suggest that prostaglandins play an important role in the beta-adrenergic receptor mechanism of renin release and the site of the action of prostaglandins is between the beta-adrenergic receptor and cyclic AMP.

Animals↗
PubMed1986

[General pharmacology of T-2588, a new oral cephem antibiotic].

A new oral cephem antibiotic, T-2588, the pivaloyloxymethyl ester of (+)-(6R, 7R)-7-[(Z)-2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3- [(5-methyl-2H-tetrazol-2-yl)methyl]-8-oxo-5-thia-1-azabicyclo[4.2. 0]oct-2-ene-2-carboxylic acid (T-2525), is mainly absorbed from the intestinal tract and biotransformed to T-2525 thereafter. General pharmacological activities of T-2588 were studied and following results were obtained. On the central nervous system, T-2588 did not show any effects at oral doses of 500-2,000 mg/kg and T-2525 produced only a slight elevation of body temperature in rabbits without any other effects at an intravenous dose of 500 mg/kg. On the respiratory and cardiovascular systems, T-2525 caused a slight hypotension and increased both respiratory rate and femoral blood flow, but no changes were observed in heart rate and electrocardiogram in dogs at an intravenous dose of 500 mg/kg. The T-2525 exerted no significant influence on blood pressure response to isoproterenol, acetylcholine or histamine, but showed a slight tendency to decrease pressor response to adrenaline in dogs at intravenous doses of 100-500 mg/kg. For the renal function in rats, T-2588 had no effects on urine volume, electrolytes and PSP excretion at oral doses of 500-2,000 mg/kg. Intravenous administration of T-2525 caused an increase of sodium excretion at 500 mg/kg and dose-dependent increases of PSP excretion at 20-500 mg/kg. Hematological studies revealed that both T-2588 at oral doses of 500-2,000 mg/kg and T-2525 at intravenous doses of 100-500 mg/kg had no effects on bleeding time in mice, blood coagulation and platelet aggregation in rats. The T-2588 exerted no effect on the gastrointestinal system in rats or mice and had no antiinflammatory activity in rats at oral doses of 500-2,000 mg/kg. The T-2525 scarcely affected the motilities of isolated smooth muscle preparations in experimental animals including stomach, ileum, colon, uterus, vas deferens and trachea at a concentration as high as 10(-3) g/ml. The T-2525 increased bile secretion in rats at intravenous doses of 100-500 mg/kg. The T-2525 slightly decreased the twitch tension of musculus gastrocnemius induced by electrical stimulation in rats at an intravenous dose of 500 mg/kg. These results indicate that T-2588 is a pharmacologically inactive antibiotic.

Animals↗
PubMed1985

A case of aortitis syndrome with severe coarctation of the aorta.

A 17 year old female with aortitis syndrome was reported. The blood pressure of upper extremities was 204/88 mmHg which was higher than that of lower extremities (88/mmHg). Chest X ray showed marked rib notchings at the lower border of the right 7th and 8th rib and left 8th ribs. Stenosis of the thoracic aorta was observed at the upper border of the 9th rib and the lower border of the 10th rib with marked development of collateral circulation. After 6 months treatment with steroids, inflammation signs were improved and thickness of the aorta was decreased which was detected by computed tomography. However, blood pressure was not decreased by the combined antihypertensive treatment.

Adolescent↗
PubMed1984

Endoscopic percutaneous gastrostomy without laparotomy.

Observation and manipulation through the endofiberscope, have resulted in a new method of establishing gastrostomy without laparotomy. Subsequent to experimental studies with dogs, the new method was employed to substitute nasogastric tube in patients. In this new procedure, endoscopic application permits the placing of stitches in close contact with the abdominal and gastric walls. The fact that no complications were observed in the patients submitted to operative treatment, is largely attributed to this type of suture. From the results obtained it would seem that this procedure can be routinely employed instead of gastrostomy with laparotomy, since it offers the advantage of being a simpler method and is more likely to be associated with a lower rate of complications.

Animals↗