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Biomedical subjects

K Takeda

Publications and source records attributed to K Takeda.

At least 1,189 records · Page 66Linked to original sources
PubMed1985

Centrally inhibitory effect of adrenaline on cardiovascular and sympathetic nerve system in urethane anesthetized rat.

The present study was undertaken to determine the central effect of adrenaline. Adrenaline was administered to the cisterna magna in urethane anesthetized rats. Following the intracisternal injections, the blood pressure dropped and reached a plateau after 15 min, the hypotensive effect continuing for at least 30 min. The heart rate also slowed concomitantly with the depressor effect. The vehicle treated rats did not show any cardiovascular responses. The cardiovascular responses in the experimental rats were accompanied by an inhibition of the sympathetic nerve activity. Pressor responses to electrical stimulation of the posterior hypothalamus were partly inhibited, while pressor responses to intravenous injections of noradrenaline remained unchanged. In DOCA hypertensive rats, the depressor responses to intracisternal injections of adrenaline were augmented. These findings suggest that adrenaline in the brain could contribute to the inhibitory mechanism of the cardiovascular system accompanied by inhibition of the sympathetic nerve system, and that this mechanism may be attenuated in DOCA hypertensive rats.

Anesthesia↗
PubMed1985

Renal denervation inhibits hypothalamo-sympathetic nerve system in normotensive and hypertensive rats.

The role of the renal nerve in influencing the hypothalamo-sympathetic nerve system to regulate the cardiovascular system was studied in normotensive Wistar and spontaneously hypertensive rats (SHR). Renal denervation attenuated pressor and sympathetic nerve responses to electrical stimulation of the hypothalamus without lowering the basal blood pressure at 48 hours after denervated operation. These findings suggest that renal denervation could inhibit the hypothalamo-sympathetic nerve system in normotensive rats. The development of hypertension in SHR was completely inhibited by renal denervation during 2 weeks of observation (from 7 to 9 weeks of age) without increasing water intake and urine volume. Pressor responses to intravenous injection of norepinephrine were not affected by renal denervation. The results show that the antihypertensive effect of renal denervation was not due to the changing of vascular reactivity. Pressor and sympathetic nerve responses to hypothalamic stimulation were strongly diminished in renal denervated rats. These results suggest that renal denervation strongly inhibited they hypothalamo-sympathetic nerve system. It is also suggested that the renal afferent nerve may facilitate the hypothalamo-sympathetic nerve system in regulating blood pressure and that this facilitation may contribute to the development of hypertension in SHR.

Animals↗
PubMed1985

Effect of l-carnitine chloride and its acetyl derivative on the electrophysiological derangement induced by palmityl-l-carnitine in isolated canine ventricular muscle.

Using the microelectrode technique, the effects of l-carnitine (LC) and acetyl-l-carnitine (ALC) on the changes in the transmembrane action potential of the canine ventricular muscle induced by palmityl-l-carnitine (PLC) were studied in comparison with those of disopyramide (D). LC (5 X 10(-3) M) itself had no effect on the electrophysiological parameters of the ventricular muscle. ALC (5 X 10(-3) M) increased the maximum rate of rise (dV/dt max) slightly and decreased the action potential duration (APD), although these changes were not statistically significant. D (1.5 X 10(-3) M) decreased dV/dt max and prolonged APD and the absolute refractory period (ARP). PLC (3 X 10(-4) M) decreased the resting membrane potential, action potential amplitude and dV/dt max, and it shortened APD and ARP. LC and ALC (5 X 10(-3) M) improved the electrophysiological derangement produced by PLC to the same degree. On the other hand, application of D (1.5 X 10(-5) M) resulted in no improvement of the electrophysiological derangement produced by PLC.

Acetylcarnitine↗
PubMed1985

Role of the alpha-adrenergic blocking effect in the acute hypotensive effect of beta-adrenergic blocking drugs with alpha-blocking activities in conscious SHR.

Acute hypotensive effects and the mechanisms of three beta-adrenergic blocking drugs with alpha-blocking activity were studied in comparison with those of prazosin, propranolol and hydralazine in the conscious spontaneously hypertensive rat (SHR). Prazosin lowered the blood pressure dose-dependently and inhibited the pressor response to phenylephrine. Three beta-adrenergic blocking drugs with alpha-blocking activity, labetalol (30 mg/kg), arotinolol (100 mg/kg) and nipradilol (100 mg/kg) also lowered the blood pressure to the same extent as prazosin (0.3 mg/kg), but the inhibition of the pressor response to phenylephrine produced by them was disproportionately slight. Propranolol (100 mg/kg) did not lower the blood pressure. These results suggest that the acute hypotensive effects of three beta-adrenergic blocking drugs with alpha-blocking activity were attributable only partially to the alpha-adrenergic blocking effect; a mechanism or mechanisms other than the alpha-adrenergic blocking effect must be invoked to explain the acute hypotensive effect produced by lower doses of these drugs in the conscious SHR.

Adrenergic alpha-Antagonists↗
PubMed1985

Effect of plasma exchange on acute pancreatitis.

Plasma exchange was performed in dogs with acute experimental pancreatitis to examine clearance of pancreatic enzymes. Plasma exchange of about 1.6 liters reduced levels of serum amylase, lipase, and phospholipase A2 in a graded fashion down to about 50%. Plasma exchange of 4 liters in a patient with severe pancreatitis produced similar clearance curves of amylase, lipase, trypsin and elastase levels.

Acute Disease↗
PubMed1985

ABO blood group antigens of human spermatozoa.

ABO blood group antigens on the membrane of human spermatozoa were investigated with the peroxidase-labelled antibody test. Spermatozoa from O secretor were incubated with saliva or seminal plasma of A and B secretors, but the specific peroxidase staining was negative. This result indicates that blood group antigens on human spermatozoa originate from spermatozoon itself, but not from seminal plasma.

ABO Blood-Group System↗
PubMed1985

[Experimental study of respiratory failure with acute pancreatitis in dogs].

In this experimental study, we investigated pathophysiology of respiratory failure with acute pancreatitis. Pancreatitis was induced by injection of 15% Na-taurocholate 1 ml/kg into the main pancreatic duct of the dogs. Experimental dogs were divided into two groups based on the value of Respiratory Index (R-Index). Group A included 9 dogs in whom respiratory failure was not recognized (R-Index less than 0.5) and Group B included 9 dogs with respiratory failure (R-Index less than 0.5). All the dogs were sacrificed 12 hours after induction of pancreatitis, and histological findings were examined. Quantity of water in the lung (Qwl) was also measured by gravimetric method. Group B showed severe hypoxia with hypocapnia, and increase of A-aDO2, R-Index, and decrease of a/A PO2. Qwl in Group B increased significantly comparing with Group A. In biochemical study, increase of serum lipase, triglyceride, free fatty acid, and angiotensin converting enzyme were observed in Group B. These results indicate that respiratory failure with acute pancreatitis is due to lung edema following injury of the capillary of the lung. The role of free fatty acid liberated by lipolysis was suggested in the mechanism of pulmonary damage with acute pancreatitis.

Acute Disease↗
PubMed1985

[Effect of peritoneal lavage on renal function in experimental acute pancreatitis].

The purpose of this study is to analyse the effect of peritoneal lavage on renal function. Pancreatitis was induced by a forceful retrograde injection of 1 ml/kg of 15% Na-taurocholate into the main pancreatic duct of the dog. Dogs were divided into two groups. Group NT consisted of 7 dogs which received no treatment. Group PL consisted of 7 dogs which underwent peritoneal lavage (20 ml/kg) 5 times for 6 hrs each. In group NT, renal blood flow started to decrease at 1 hr after Na-taurocholate injection. At 6 hrs, renal blood flow decreased to 50% of the initial level. On the other hand, renal blood flow in group PL decreased to only 75% of the initial value at 6 hrs. Although FENa (excreted fraction of the filtered sodium) and urine N-acetyl-beta-D-glucosaminidase elevated in group pL, these values were significantly lower than those in group NT. Serum pancreatic enzyme levels in group pL were also kept lower than in group NT from 3 hrs to the end of the experiment with a significant difference. These results suggest that peritoneal lavage is effective not only for diminishing serum pancreatic enzymes but also protecting the kidney from ischemic damage on acute pancreatitis.

Acute Disease↗
PubMed1985

Replication of measles virus and localization of the viral antigens in long-term infection in organotypic cultures of hamster dorsal-root ganglion.

To investigate measles virus replication and expression of the individual viral proteins in differentiated various types of cells in neural tissues free from immunological effects organotypic cultures of hamster dorsal-root ganglion were employed. Measles virus caused long-term infection up to 100 days in these cultures to which the virus was inoculated after they had been well-organized with myelination. Electron microscopy and immunofluorescence technique demonstrated that the infection proceeded first in cells other than neurons and then gradually spread to neurons leading to degeneration of all neurons. By immunofluorescence staining with monoclonal antibodies against measles virus structural proteins, hemagglutinin (HA), fusion (F) protein, nucleocapsid major (N) protein, phosphorylated (P) protein and matrix (M) protein, all the viral antigens including M protein but except P protein were clearly shown in the cytoplasm of neurons and N and F proteins were observed also in neurites. In non-neuronal cells all the viral antigens including P protein were observed in the cytoplasm. Only N antigen was shown also in the nucleus of all cell types including both neurons and Schwann cells. These findings were discussed in relation to the viral replication pattern in subacute sclerosing panencephalitis.

Animals↗