Protective effect of Tianqi Hangli Recipe () extract on high sustained positive acceleration stress-induced myocardial mitochondrial injury in rats.

Objective: To explore the protective effect of Tianqi Hangli Recipe () extract (THRE) on high sustained positive acceleration (+Gz) stress-induced myocardial mitochondrial injury in rats.

Methods: Seventy-two male SD rats were randomly assigned to various groups with 12 rats per group: blank control group, stress control group, high +Gz stress group, low-dose THRE group (0.75 g/kg), medium-dose THRE group (1.

Effect of high sustained +Gz stress on myocardial mitochondrial ultrastructure, respiratory function, and antioxidant capacity in rats.

Exposure to high sustained positive acceleration (+Gz) is known to have a pathophysiological effect on the heart of the rat. As critical regulators of cardiac myocyte survival and death, mitochondria may be crucially involved in +Gz-induced pathogenesis. It was, therefore, of interest to investigate myocardial mitochondrial ultrastructure, respiratory function, and antioxidant capacity in rats after exposure to +10 Gz for 5 min.

[Myocardial free radical metabolic changes in rats after repeated high +Gz exposure and protective effects of low-G preconditioning and tea polyphenols].

Aim: To determine whether repetitive exposure to high sustained +Gz acceleration induces persisting changes in the myocardial free radical metabolism and observe the protective effects of low-G training and antioxidant tea polyphenols (TP).

Methods: Thirty-two male Wistar rats were randomly divided into four groups (n=8 each): group A, restrained, was only submitted to +1 Gz for 5 min. Group B, centrifuged, was exposed to five plateaus of 30 s at +10 Gz for intermittent times, three times a week, for three weeks.

[Effects of low-G preconditioning on contractive ability of left ventricle and contents of endothelin and prostacycline in myocardium of rats after repeated +10 Gz stress].

Objective: To further test the protective effect of low-G pre-conditioning on +Gz stress induced cardiac damage.

Method: Forty-two male Wistar rats were randomly divided into 3 groups (n=14 for each group): group A (+1 Gz group), group B (+10 Gz group) and group C (low-G pre-conditioning group). The rats in group B were exposed to five +10 Gz plateaus of 30 s with 1 min intervals at +1 Gz, 3 times a week, for 3 weeks; while group A were only submitted to +1 Gz for 5 min.

Preliminary studies on the structure-activity and time-effect relations of the central stimulating effects of modafinil in mice.

Objective: To observe the structure-activity and time-effect relations of the central stimulating effects of modafinil for further pharmaceutical design and development and rational use of this kind of stimulant.

Method: Male mice served as subjects. The experiment was divided into two parts: 1) comparison between the dose (60, 120, 240 mg/kg) and temporal features of the effects of modafinil and its two derivatives on locomotor activity of mice; 2) Observation of the stimulating effects of modafinil (120 mg/kg) given during the day or night.

[Effects of modafinil on visual and auditory reaction abilities and subjective fatigue level during 48 h sleep deprivation].

Objective: To investigate the effects of modafinil, a new central stimulant, on visual and auditory motion reaction ability and subjective fatigue level during 48 h sleep deprivation (SD).

Method: Six male healthy young volunteers were exposed to two 48 h periods of continuous wakefulness during the crossover experiment. In one period, three 200 mg doses of modafinil were given and in the other, separated by two weeks, matching placebos were administered.

Changes of cardiac catecholamines in rats after repeated +Gz exposures and protective effects of low-G preconditioning and tea polyphenols.

Objective: To observe whether repeated +Gz exposures could induce metabolic disorder of cardiac catecholamines in rats as well as the protective effects of low-G preconditioning and tea polyphenols (TP).

Method: Thirty-two male Wistar rats were randomly divided into 4 groups (n=8): group A (control), only submitted to +1 Gz 5 min; group B (+10 Gz stress), exposed to +10 Gz 30 s, 5 times/d with +1 Gz 1 min interval, 3 d/wk, for 3 wk in total; group C (low G preconditioning), +Gz stress parameters were the same to that of group B, but the rats were submitted to +2 Gz 5 min 1 h prior to +10 Gz exposure; group D (TP protection), + Gz stress parameters were the same to that of group B, but TP was given orally to the rats at the dose of 200 mg/kg 1 h prior to +10 Gz exposure. These animals were decapitated on the next morning of the last centrifuge run, and the hearts were taken out and stored in liquid nitrogen immediately.