ABSTRACT
Objective To compare the influence of general anesthesia and spinal anesthesia on the mortality in rats with fat embolism.Methods Three hundred and seventy five rats were randomly assigned to receive general anesthesia （group GF,n=125）,spinal anesthesia （group SF,n=125）,or no anesthesia （group F,n=125）.Rats were injected with a half lethal dose of fat from caudal vein 20 min after anesthesia induction. The mortality was recorded at 2,8,12,and 24 h after fat injection,respectively.Results The mortality was lower in group GF than those in groups SF and F （P0.05）,while there was no statistical difference between group SF and group F.Conclusion The mortality in rats with fat embolism under general anesthesia was lower than that under spinal anesthesia.
ABSTRACT
Objective:To determine the half lethal dose(LD50) of paraquat in rats and to establish a relatively safe and stable pathological animals model of pulmonary fibrosis.Methods: Ninety-six SD rats totally in half genders.Fifty SD rats in half genders were randomly divided into 5 groups,each had 10 rats.Feed the rats with different doses of liquor of paraquat intraperitoneally one time and definite the half lethal dose of one and two weeks.After that,prepare another forty-six SD rats,also in half genders,as intonication group,twenty-eight rats were treated with the liquor of paraquat in dosage of 18 mg/kg intraperitoneally.As control group,sixteen rats were treated with equivalent volume of normal saline.Observe the toxic symptom daily and rats were sacrificed on day 1,3,5,7,14,21,28,35 and 42 respectively for the histological examination.Results: The half lethal doses of intraperitoneal paraquat of 1 and 2 weeks were 18.27 and 17.29,with 95% confidence intervals of 16.61-20.09 and 15.99-18.67,respectively.After intraperitoneal paraquat injection at the dose of 18 mg/kg,typical toxic symptoms were observed at different times in the rats.The whole process of acute lung injury and fibrosis induced by paraquat intoxication could be seen with the naked eyes or under the light microscope.Conclusion: Paraquat has a strong toxicity to rats.A proper dose of paraquat solution can not only reduce the number of experimental rats,but also induce typical pulmonary fibrosis in rats.