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Biomedical subjects

C F Chen

Publications and source records attributed to C F Chen.

At least 361 records · Page 20Linked to original sources
PubMed1982

Acute toxicity of PR toxin, a mycotoxin from Penicillium roqueforti.

The toxic effects of PR toxin were observed in mice, rats, anesthetized cats and isolated rat auricle preparations. In mice and rats the toxic effects included abdominal writhing, decrease of motor activity and respiratory rate, weakness of hindleg and ataxia. In mice, the i.p. LD50 was 5.8 mg/kg. In mice, rats and cats PR toxin given i.p. caused ascites fluid an edema in the scrotum and lungs, and i.v. injection caused edema in the lungs, giving rise to a large volume of pleural and pericardial fluid. In rats, at the LD50 dose level (11.6 mg/kg, i.p. and 8.2 mg/kg, i.v.), the water content in the lungs was increased, but in the skin it was decreased. Blood K+, hematocrit, red blood cell, white blood cell, hemoglobin, uric acid, cholesterol, blood urea nitrogen and alkaline phosphatase concentrations were all increased, while the total protein and albumin contents were decreased after i.p. injection of PR toxin. High content of protein was found in the pleural fluid and fluid due to ascites. In anesthetized cats the blood pressure and respiratory rate were progressively decreased and the heart rate was reflexly increased after i.p. injection. The i.v. injection produced a multiple response on the arterial blood pressure, but with a progressively decreasing heart rate. Arrhythmias were observed in the late shock stage in the case of i.p. or i.v. injection. In the isolated rat auricle preparations contractile force was more affected that heart rate. We conclude that PR toxin produced acute toxic effects in animals via an increase of capillary permeability and a direct damage to the lungs, heart, liver and kidney.

Animals↗
PubMed1982

The effects of thermal injury on gastrointestinal motor activity in the rat.

Gastrointestinal motor function was studied in conscious rats. The gastric emptying time, small intestinal motility and the colonic transit time were measured. A burn injury, covering about 15 per cent of the body surface area was applied to experimental animals; control animals received a mock burn. Burn injury caused a marked inhibition of gastrointestinal motility. This inhibition was significantly improved by a continuous saline infusion, but saline infusion alone had no effect on the gastrointestinal propulsive motility of normal rats.

Animals↗
PubMed1981

In vivo and in vitro studies on the mechanism of cardiovascular effects of Wu-Chu-Yu (Evodiae fructus).

The effects of the Chinese herb Wu-Chu-Yu (Evodiae fructus) on the cardiovascular function were assessed in anesthetized cats, conscious rats, and isolated preparations of rat aortic strip and auricle. In anesthetized cats, intravenous administration of alcohol-water crude extracts of Wu-Chu-Yu (0.03-0.24 g/kg) produced a dose-dependent hypertension and an increased contractile force of nictitating membrane which lasted for more than 5 min in higher doses. Phentolamine, but not tetraethylammonium antagonized hypertension and the increased contractile force of nictitating membrane induced by Wu-Chu-Yu. In conscious rats, hypertension was also observed by intraperitoneal administration of Wu-Chu-Yu (6 g/kg). Bilateral nephrectomy, administration of phentolamine or propranolol, all significantly decreased the hypertensive effect of Wu-Chu-Yu. Pretreatment with reserpine 24 hours in advance did not change the pressor effect of the crude extract. In aortic strip preparations, Wu-Chu-Yu caused the increase of contractile force, and the dose-response curve was parallel shift to the right in the presence of phentolamine. In auricle preparations, Wu-Chu-Yu produced positive inotropic and positive chronotropic effects, and the presence of propranolol changed the slope of Wu-Chu-Yu's dose-inotropic effect curve and reversed the chronotropic effect from positive to negative. Both in vivo and in vitro results suggested that alpha and beta adrenoceptors were directly involved in the cardiovascular effects of Wu-Chu-Yu.

Animals↗
PubMed1981

Protective effects of Carica papaya Linn on the exogenous gastric ulcer in rats.

The effects of Carica papaya Linn on exogenous ulcer and histamine-induced acid secretion were studied in rats. The latex of the unripened fruit of C. papaya was effective in protecting the exogenous ulcer. It significantly lessened the acid secretion induced by intravenous infusion of histamine in chronic gastric fistulated rats. Crystalline papain was also effective in protecting the exogenous ulcer and in decreasing the histamine-induced acid secretion in rats. The conclusion is that papain is the active principle in C. papaya that exerts the ulcer-protective effect.

Animals↗
PubMed1978

Effect of ketamine on thermoregulation in rats.

Intraperitoneal administration of ketamine produced dose-dependent hypothermia at the ambient temperatures (Ta) of both 8 and 23 degrees C in unanesthetized rats. At a Ta of 8 degrees C, the hypothermia was brought about solely by a decrease in metabolic heat production. There were no changes in either the tail skin temperature (Ttail) or the sole skin temperature (Tsole). At a Ta of 23 degrees C, the hypothermia was due to an increase in Ttail, and increase in Tsole, and a decrease in metabolic heat production. However, at a Ta of 31 degrees C, there were no changes in rectal temperature in response to ketamine application, since neither heat production nor skin temperatures (e.g., Ttail and Tsole) was affected by ketamine at this Ta. The data indicate that the effect of the drug treatment may be to decrease heat production and (or) increase heat loss.

Animals↗