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Objective To study the application of implantable telemetry and whole-body plethysmography to observe the changes of circadian rhythm in conscious rats and evaluate the pharmacological safety of doxofylline, and to provide a basis for the future application of this technological system for drug safety evaluation.Methods Eight healthy SPF Sprague-Dawley rats were used in this study, 4 males and 4 females.The rats were implanted with telemetry transmitters by surgery to establish a telemetry system combined with plethysmography to observe the changes of 24 h physiological parameters and circadian rhythm in conscious rats at 14 d after operation, including heart rate (HR), blood pressure, the time interval from the Q wave to point A in the ECG of the aortic pressure wave (QA interval), respiration, activity, body temperature and pulmonary function parameters.The rats were divided into 3 groups: normal control group, doxofylline 40 mg/kg and 80 mg/kg groups, and the performance was validated by aerosolizing saline, doxofylline 40 mg/kg and 80 mg/kg inhalation, respectively, to observe the changes in physiological parameters after the drug administration.Results The physiological parameters of rats showed obvious changes in circadian rhythms at 14 d after operation.Compared with the normal control group, the doxofylline 40 mg/kg-treated group showed significantly increased changes of HR, tidal volume (TV), minute ventilation (MV), 50% expiratory flow (EF50), peak inspiratory flow (PIF) and peak expiratory flow (PEF) (P0.05).Compared with the normal control group, the group treated with doxofylline 80 mg/kg had significantly increased HR, blood pressure, TV, MV, EF50, PIF and PEF (P0.05).Conclusions The application of implantable telemetry and whole-body plethysmography in this study does not obviously affect the circadian rhythm, and can sensitively monitor the relevant cardiovascular and respiratory parameters in conscious rats.It can be used in drug safety pharmacological research of cardiovascular and respiratory systems in conscious rats.
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Objective To observation dynamic changes and gender difference of heart rate variability and blood pressure variability in unbonded spontaneously hypertensive rats using Telemetry technology .Method Taking sixteen spontaneously hypertensive rats of 3-month-old in SPF grade, there were implanted TL11M2-C50-PXT device intraperitoneally.Seven days later, respectively monitoring chainless blood pressure and electrocardiogram for 24 h continuously time using telemetry system when 3, 5, 7 months of age in spontaneously hypertensive rats .Analysing 24 h systolic pressure , mean blood pressure , diastolic blood pressure , heart rate variability and blood pressure variability . Result Systolic pressure , diastolic pressure and mean pressure , blood pressure variability increased with age of the moon increased in spontaneously hypertensive rats , moreover female SHR rats of blood pressure variability was significantly lower than that of the male rats .Correlated indexes of heart rate variability had no obvious change Between three to seven month -old in male spontaneously hypertensive rats .But RR interval , SDNN, TP, VLF and HF increased significantly with age of the moon increased in female spontaneously hypertensive rats , moreover the female SHR rats of TP , VLF and HF index of heart rate variability were lower than the male rats .Conclusion With the SHR rats age and blood pressure , blood pressure variability increased , and the female SHR rat variability in blood pressure and heart rate was significantly lower than that of the male .
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Objective To study the the changes of serum tumor necrosis factor-?(TNF-?)and epidermal growth factor (EGF) in rats with experimental liver fibrosis and its significance. Methods All the SD rats were randomly divided into the normal group and the model group. The rats in the model group were subcutaneously injected with 40%CCl4 according to 0.3ml/100g body weight twice one week for the first four weeks, the initial dose was double. In the following five weeks, the rats were injected 40% CCl4 of 0.2ml/100g body weight twice one week.The rats in the normal group were subcutaneously injected with equal dosage of saline,mentioned aboveo.At the end of the ninth week,the serum was obtained,the levels of serum TNF-?, EGF were detected with radioimmunity, with HE stains, the severity of inflammation and fibrosis in all liver tissuses were measured by semiquantitative scoring. Results The fibrosis scorings, the levels of serum TNF-?, EGF in the model group were higher than that in the normal group, the difference between the two group was significance(P