Biomedical subjects

M T Hsieh

Publications and source records attributed to M T Hsieh.

At least 37 records · Page 2Linked to original sources

PubMed1996

Effects of Hemerocallis flava on motor activity and the concentration of central monoamines and its metabolites in rats.

In this study, we used behavioral and biochemical methods to investigate the effects of Hemerocallis flava (Liliaceae) (abbreviated as HF) on motor activity and the concentration of monoamines in rats. The water fraction of the resuspended HF extract was most active in reducing the motility in rats. The water fraction of the HF extract enhanced the reduction of locomotor activity produced by alpha-methyl-p-tyrosine and 5-hydroxytryptophan, but it reduced the increase of locomotor activity produced by L-dopa plus benserazide and p-chlorophenylalanine. Furthermore, the water fraction of the HF extract significantly decreased the concentration of norepinepherine in the cortex and the concentration of dopamine and serotonin in the brain stem. It also increased the concentration of vanilylmandelic acid in the cortex, homovanillic acid and 5-hydroxyindole-acetic acid in the brain stem. These results suggest that the reduction of locomotor activity produced by the water fraction of HF extract may be related to the decrease in the concentration of norepinepherine in the cortex and the concentration of dopamine and serotonin in brain stem.

5-Hydroxytryptophan↗

PubMed1996

Effects of Gastrodia elata and its active constituents on scopolamine-induced amnesia in rats.

The effects of the rhizome of Gastrodia elata Blume (Orchidaceae) (abbreviated as GE) and its active constituents on learning and memory by using the one-trial passive avoidance task were studied in rats. At the 1.0 g/kg dose administered for one week, the methanol extract of GE significantly prolonged the shortened step-through latency induced by scopolamine in the passive avoidance task. Furthermore, at the 50.0 mg/kg dose administered for one week, the ethyl acetate and n-butanol fractions of the methanol extract prolonged the shortened step-through latency induced by scopolamine in rats. Gastrodin, isolated from the n-butanol fraction of the methanol extract, and p-hydroxybenzyl alcohol, isolated from the ethyl acetate fraction of the methanol extract, also significantly prolonged the shortened step-through latency induced by scopolamine on the passive avoidance task. These results suggested that gastrodin and p-hydroxybenzyl alcohol may be the active constituents of GE.

Amnesia↗

PubMed1996

Antihypertensive effects of DL-tetrahydropalmatine: an active principle isolated from Corydalis.

1. The effects of DL-tetrahydropalmatine (DL-THP) on cardio-vascular function and hypothalamic release of monoamines were assessed in rats under urethane anaesthesia. 2. Intravenous administration of DL-THP (1-10 mg/kg) produced hypotension, bradycardia, a decrease in hypothalamic serotonin and noradrenaline release and an increase in hypothalamic dopamine release in rats. 3. Intrahypothalamic administration of DOI (a serotonergic 5-HT2 receptor antagonist) or apomorphine (a dopamine D2-receptor agonist) produced the opposite effects and reversed DL-THP-induced hypotension and bradycardia. 4. The data suggest that DL-THP acts through the 5-HT2 and/or D2-receptor antagonism in the hypothalamus to induce hypotension and bradycardia in rats.

Amphetamines↗

PubMed1996

Inhibitory effects of (+/-)-tetrahydropalmatine on thyrotropin-stimulating hormone concentration in hyperthyroid rats.

The effects of (+/-)-tetrahydropalmatine ((+/-)-THP) on the hypothalamus-pituitary-thyroid system in rats were investigated. Thyroid function experiments indicated that (+/-)-THP produces significant decreases in thyroid function in hyperthyroid rats after 14 days of treatment. These effects were the same as those of propylthiouracil. However, propylthiouracil also decreased thyroid function in normal rats. Measurements of thyrotropin-stimulating hormone (TSH) demonstrated that (+/-)-THP decreased TSH in hyperthyroid rats after 14 days of treatment; however, propylthiouracil increased TSH in hyperthyroid rats. (+/-)-THP had no influence on TSH, or thyroid and pituitary weight in normal and hyperthyroid rats. We conclude that (+/-)-THP has an antithyroid function and the mechanism of action may be related to the inhibition of TSH in the pituitary.

Animals↗

PubMed1996

p-Hydroxybenzyl alcohol attenuates learning deficits in the inhibitory avoidance task: involvement of serotonergic and dopaminergic systems.

p-Hydroxybenzyl alcohol (HBA), an aglycone of gastrodin, is an active ingredient of Gastrodia elata BLUME. In this study, we investigated the action of HBA on acquisition of an inhibitory avoidance response in rats and used piracetam as a positive control. The results indicated that scopolamine, a cholinergic receptor antagonist, injected before training impaired retention. HBA did not attenuate the scopolamine-induced impairment, but piracetam did. p-Chloroamphetamine, a serotonin releaser, injected before training impaired retention. HBA at 5 mg/kg and piracetam at 100 mg/kg could counteract the p-chloroamphetamine-induced deficit. Apomorphine, a dopaminergic receptor agonist, also impaired retention. HBA at 5 mg/kg and piracetam at 300 mg/kg could ameliorate the apomorphine-induced amnesia. The above results indicated that HBA, different from piracetam, can attenuate impairments induced by p-chloroamphetamine and apomorphine, but had no effect on impairment induced by scopolamine in an inhibitory avoidance task in rats. Such findings suggest that HBA may act through suppressing dopaminergic and serotonergic activities and thus improves learning.

Animals↗

PubMed1995

Effects of ginseng on the blood chemistry profile of dexamethasone-treated male rats.

Ginseng, a panacea in the Orient, has been widely investigated in the last two decades and found to possess a wide range of pharmacological activities including anti-fatigue properties, a transient regulatory action on metabolism and blood pressure, and an increase in the hypothalamo-pituitary-adrenocortical activities. However, a panoramic clinical chemistry study including adrenal and thyroid functions has never been done before. Two experiments with the same design but different concentrations of dexamethasone were performed in this study. The results obtained from the two experiments indicated that ginseng administration at this regime did not influence the blood chemistry profiles in normal rats, but significantly decreased AST and ALT levels from those in dexamethasone-treated ones. It implies that ginseng has a liver-protective effect. Meanwhile, ginseng therapy restores the adrenal and thyroid functions of rats inhibited by dexamethasone treatment.

Animals↗

PubMed1995

DL-tetrahydropalmatine-produced hypotension and bradycardia in rats through the inhibition of central nervous dopaminergic mechanisms.

The effects of DL-tetrahydropalmatine (THP; a main active substance of the Chinese herb corydalis), haloperidol (a dopamine D2 receptor antagonist), apomorphine and amphetamine on cardiovascular function and striatal dopamine (DA) release were compared in rats under general anesthesia. Intravenous administration of THP (1-10 mg/kg) or haloperidol (0.5-1.25 mg/kg) produced hypotension, bradycardia and increased DA release in the striatum. On the other hand, amphetamine (0.5-1.25 mg/kg) produced hypertension, tachycardia and increased striatal DA release. However, intravenous injection of apomorphine (0.5-1.25 mg/kg) produced hypotension, bradycardia and decreased striatal DA release. In addition, the THP-induced hypotension was attenuated by pretreatment with spinal transection or amphetamine, while the THP-induced bradycardia was attenuated by pretreatment with bilateral vagotomy or amphetamine. Thus, it appears that THP acts through DA D2 receptor antagonism to induce hypotension and bradycardia in rats.

Amphetamine↗

PubMed1995

Hypotensive and bradycardic effects of dl-tetrahydropalmatine mediated by decrease in hypothalamic serotonin release in the rat.

In anesthetized rats, intravenous administration of dl-tetrahydropalmatine (dl-THP, 1-10 mg/kg) elicited proportional hypotension, bradycardia and decreases in hypothalamic serotonin (5-HT) release (measured by carbon-fiber electrodes in combination with voltammetry). In addition, postsynaptic blockade of 5-HT2 receptors with cyproheptadine (2-5 mg/kg, i.v.) or ketanserin (2-5 mg/kg, i.v.) produced both hypotension and bradycardia, while stimulation of 5-HT2 receptors with 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (10-250 mg/kg, i.v.) produced both hypertension and tachycardia. The dl-THP-induced hypotension and bradycardia could be reversed by DOI treatment. The data indicate that dl-THP decreases both arterial pressure and heart rate through a serotonergic release process in the hypothalamus.

Adrenergic Agents↗

PubMed1994

Effects of DL-tetrahydropalmatine on motor activity and the brain monoamine concentration in rats.

Behavioral and biochemical methods were used in this study to investigate the effect of DL-THP on motor activity and the concentration of monoamines in rats. Experimental results indicated that DL-THP significantly decreased the motor activity of rats and showed a dose-response pattern; in addition, it produced rigidity at a higher dosage. DL-THP also enhanced the hypomotility induced by haloperidol, but reduced the hypermotility produced by apomorphine. Furthermore, DL-THP significantly decreased the concentration of norepinephrine (NE), dopamine (DA) in the cortex and brain stem at lower and higher dosages, and the concentration of serotonin (5-HT) in the cortex at higher dosages. DL-THP also increased the concentration of homovanillic acid (HVA) in the cortex and brain stem at lower and higher dosages, and the concentration of 5-hydroxyindole acetic acid (5-HIAA) in the cortex at higher dosages. These results suggest that the hypomotility produced by DL-THP may be due to the increase in the turnover rate of dopamine in the cortex and brain stem at lower and higher dosages, and of serotonin in the cortex at higher dosages.

Animals↗

PubMed1993

Effects of palmatine on motor activity and the concentration of central monoamines and its metabolites in rats.

We used behavioral and biochemical methods to investigate the sedative effect of palmatine on locomotor activity and the concentration of monoamine in rats. It was found that palmatine enhanced the hypomotility induced by alpha-methyl-p-tyrosine, reserpine and 5-hydroxytryptophan, but reduced the hypermotility produced by L-dopa plus benserazide and p-chlorophenylalanine. Furthermore, palmatine significantly decreased the concentration of dopamine and homovanillic acid in the cortex and the concentration of serotonin in the brain stem, and it increased the concentration of 5-HT in the cortex and 5-hydroxyindole acetic acid in the brain stem. These results suggest that the sedative mechanism of palmatine may be related to the decrease in the concentration of catecholamine in the cortex and serotonin in brain stem and the increase in the concentration of 5-HT in the cortex.

5-Hydroxytryptophan↗

PubMed1991

Studies on the anticonvulsive, sedative and hypothermic effects of Periostracum Cicadae extracts.

The anticonvulsive, sedative and hypothermic effects of water and ethanol extracts of Periostracum Cicadae (PC), the cast off skin of Cryptotympana atrata were studied. The water-extract of whole Periostracum Cicadae (PCws) had anticonvulsive, sedative and hypothermic effects in rats. Orally, it decreased carrageenin-induced hyperthermia. The hypothermic effect of PCws was potentiated by 5-hydroxytryptophan and antagonized by p-chlorophenylalanine. PCws enhanced the decrease in locomotor activity induced by alpha-methyl-p-tyrosine or 5-hydroxytryptophan and reduced the increase in locomotor activity produced by levodopa plus benserazide or p-chlorophenylalanine. From these results, it was concluded that the sedative and hypothermic effect of PCws may be due to an increase in central serotonergic activity.

Animals↗

PubMed1991

Isolation and typing of herpes simplex virus from clinical specimens collected at National Taiwan University Hospital, 1981-1990.

From 1981 to 1990, 10,167 clinical specimens were collected at National Taiwan University Hospital from the cases with suspected viral infections. Three hundred of herpes simplex virus (HSV) were isolated from these samples (isolation rate; 3.0%). One hundred and fifty-one strains were isolated from non-genital, and 149 strains from genital areas. HSV strains were typed by direct immunofluorescence staining technique. The type specific monoclonal antibodies were used in the test. Most of the HSV strains isolated from non-genital areas were type 1 (HSV-1) (147/151, 97.4%) whereas most of the strains from genital areas were type 2 (HSV-2) (140/149, 94.0%). All nine strains of HSV-1 isolated from genital areas were from female patients. The predominance of HSV-1 in non-genital area infections, and of HSV-2 in genital area infections, did not change during the ten years under review.

Female↗

PubMed1990

Long-term reno-cardiovascular effects of orally administered aconiti tuber in humans.

The reno-cardiovascular effects of Aconiti Tuber were studied. In a controlled, double-blind, and randomized clinical trial, it was found that in 9 months, Aconiti Tuber, after preparation (120 degrees C, 40 min), (1) had no apparent adverse effects, (2) showed positive inotropic, positive chronotropic, and vasodilator effects, (3) increased renal blood flow, and glomerular filtration rate, Na+/Cl-/K+ excretions. The renal function test results could be interpreted as secondary to hemodynamic changes. We conclude that specially prepared Aconiti Tuber may be a promising cardiotonic agent.

Adult↗

PubMed1988

Effects of san-huang-hsieh-hsin-tang on central monoaminergic and GABAergic systems in rats.

In this paper, the effects of San-Huang-Hsieh-Hsin-Tang on central monoaminergic and GABAergic systems were studied in rats. It was found that San-Huang-Hsieh-Hsin-Tang significantly (1) prolonged the period from the onset of clonic to tonic convulsions induced by picrotoxin, (2) prolonged the sleep duration induced by hexobarbital, (3) inhibited central catecholaminergic activity, (4) promoted central GABAergic activity, and (5) decreased the turnovers of central norepinephrine and dopamine.

Animals↗

PubMed1988

Effects of paweiwan on streptozotocin-induced hyperglycemia in rats.

The ancient Chinese remedy of Paweiwan was used by patients with polyuria, polydipsia, and polyphagia. The present study investigated the hypoglycemic effects of Paweiwan using streptozotocin-induced hyperglycemic rats. The effects on serum glucose in a 4-day course, in a 7-week course, on the standard oral glucose tolerance test, and on the liver glycogen content were studied. In the glucose tolerance test, chlorpropamide and insulin were used as the positive controls and 0.5% CMC (Carboxymethylcellulose) was used as the negative control. We found that Paweiwan decreased the baseline glucose concentration, ameliorated the blood glucose elevation after glucose challenge, and increased liver glycogen content. The results may imply that Paweiwan increases glucose entrance into cells.

Animals↗

PubMed1987

Hemodynamic effects of orally administered Sunitang in humans.

The hemodynamic effects of Sunitang, an ancient Chinese remedy for general weakness, weak pulse, and cold extremities, were studied. In study, 1, 10 patients with left ventricular failure received Sunitang in single oral doses of 250, 500, and 1000 mg in a double-blind manner. Sunitang showed dose-related positive inotropic, chronotropic, and vasodilator effects. The effects reached their maximum within 30 to 60 minutes and lasted for 6 hours. In study 2, 77 patients with left ventricular failure who had not been treated satisfactorily by the conventional methods entered a controlled (parallel design), double-blind study for 1 month. When they entered the study they were in steady states. They continued their original medications throughout the month. Sunitang showed additional positive inotropic, chronotropic, and vasodilator effects. In this study no apparent adverse effects of Sunitang were noted. We conclude from these results that Sunitang may be useful in heart failure and bradycardia.

Cardiotonic Agents↗

PubMed1986

Suanzaorentang in cardiac patients with anxiety.

In 60 patients with cardiac symptoms and anxiety, the anxiolytic effect of the ancient Chinese remedy Suanzaorentang has been studied. It was a promising anxiolytic remedy, without apparent adverse effects on the cardiovascular system, and appearing not to interact with other drugs.

Adult↗

PubMed1986

Two-year experience with "San-Huang-Hsieh-Hsin-Tang" in essential hypertension.

In this paper, the long-term effects of the ancient Chinese formula of San-Huang-Hsieh-Hsin-Tang on patients with essential hypertension were reported. San-Huang-Hsieh-Hsin-Tang could significantly improve the hyperkinetic states of the cardiovascular system, improve the accompanying sympathetic symptoms, lower serum norepinephrine and have no apparent side effects.

Adult↗