BRD4 expression in patients with essential hypertension and its effect on blood pressure in spontaneously hypertensive rats.

The objective of this study was to investigate BRD4 expression in patients with essential hypertension (EH) and its effects on the blood pressure in spontaneously hypertensive (SHR) rats. BRD4 expression was detected by quantitative real-time polymerase chain reaction and western blot in 163 patients with EH and its relation to systolic blood pressure and diastolic blood pressure were analyzed accordingly. In vivo, rats were divided into WKY (Wistar-Kyoto rats), SHR (spontaneously hypertensive rats), SHR + JQ1 (BRD4 inhibitor), and SHR + Vehicle control. Rats' blood pressure was measured by the tail-cuff method. The protein expressions related to inflammation and oxidative stress of rats were determined. BRD4 was higher in patients with EH than healthy controls, which was positively correlated to systolic blood pressure and diastolic blood pressure of enrolled subjects including patients with EH and healthy controls. Rats in the SHR group showed reduced food-intake, decreased body weight, and gradually increased blood pressure compared with WKY group. Besides, SHR rats were upregulated in plasma levels of Ang II, ET-1, MDA, IL-6, and TNF-α, and substantially downregulated in NO, NOS, and SOD levels. Moreover, eNOS activity in aortic tissues of SHR rats declined obviously, whereas the content of nitrite and O2-, the activity of NADPH oxidase and NADH oxidase, and the expression of p-NF-κB p65 went up statistically, which could be partially reversed by JQ1. BRD4 was highly expressed in patients with EH, and inhibiting BRD4 could reduce oxidative stress and inflammatory response, alleviate endothelial cell damage, ameliorate aortic injury, and lower blood pressure, supporting the hypothesis that BRD4 inhibition could be a potential target for the clinical treatment of patients with EH.

[Effect of nano-SiO2 exposure on spatial learning and memory and LTP of hippocampal dentate gyrus in rats].

OBJECTIVE: To study the effect of nano-SiO2 on spatial learning and memory. METHODS: Twenty-four male rats were randomly divided into 3 groups: control group (C group), low dose group (L group) and high dose group (H group). The rats were intragastrically administrated with nanometer particles at 25 and 100 mg/kg body weight every day for 4 weeks. After exposure, the ability of learning and memory of rats was tested by Morris water maze, and electrophysiological brain stereotactic method was used to test long-tear potentiation (LTP) in dentate gyrus (DG) of the rats. RESULTS: The increase rate of body weight in H group was reduced significantly compared with C group ( P < 0.05). In the space exploration experiment of Morris water maze test, the escape latency of H group was longer than that of C group (P < 0.05). The rats of H group spent less time in finding the target quadrant (P < 0.05) . The rate of LP induction of H group was significantly lower than that of C group (P < 0.05). After high fre quency stimulation (HFS), The changes of amplitude of population spike (PS) of L group and H group were lower than those of C group significantly (P < 0.05, P < 0.01). CONCLUSION: Nano-SiO2may result in impairment of spatial learning and memory ability by reducing the rate of LTP induction and the increase of PS in hippocampus.

[Effects of retinol acid and triiodothyronine on alleviating the impairment of cognitive function by sleep deprivation].

OBJECTIVE: To explore the effects of retinol acid (RA) and triiodothyronine (T3) on alleviating the impairment of cognitive function by sleep deprivation (SD). METHODS: Male Wistar rats were divided into 4 groups: control group (C group), sleep deprivation group (SD group), sleep deprivation + RA group (SD + RA group) and sleep deprivation + T3 group (SD + T3 group). Open field test (OFT) was used to observe the nervous behavior of the rats after SD and electrophysiological brain stereotactic method was used to test long-term potentiation (LTP) in dentate gyrus (DG) of the rats. Ng protein expression was determined by Western blot. RESULTS: Compared with the SD group, the number of crossing in OFT, the changes of amplitude of population spike (PS) and the expression of Ng protein in hippocampus were higher significantly in the SD + RA and SD + T3 groups. All of these had not significant difference comparing with the C group. CONCLUSION: RA and T3 may alleviate the restrain state of neural system after SD by augmenting the expression of Ng protein in hippocampus.

Changes of 5-hydroxytryptamine and tryptophan hydroxylase expression in the ventral horn of spinal cord.

OBJECTIVE: To investigate changes of 5-hydroxytryptamine (5-HT) and its synthesis rate-limiting enzyme tryptophan hydroxylase (TPH) in the ventral horn of spinal cord after exercise-induced fatigue, and to further discuss the mechanism of exercise-induced central fatigue at spinal level. METHODS: Sixteen healthy adult Wistar rats were randomly divided into 2 groups: exercise-induced fatigue group and control group. Immunohistochemical staining for 5-HT and TPH in the ventral horn were performed and analyzed quantitatively. The mean optic densities of 5-HT and TPH positive fibers or terminals were measured by computerized image analyzer. RESULTS: Both 5-HT and TPH positive fibers/terminals decreased in the exercise-induced fatigue group. The immunohistochemical staining was weaker and the mean optic densities decreased obviously in the fatigue group compared with those in the control group (P< 0.05). CONCLUSION: 5-HT and TPH in the ventral horn of spinal cord might be involved in exercise-induced fatigue.

[The changes of neurotransmitter content in spinal cord after exercise-induced central fatigue].

AIM: To investigate the changes of neurotransmitter concentration in spinal cord after exercise-induced central fatigue and study the mechanism of central fatigue at spinal level. METHODS: Establish exercise-induced central fatigue model according to Bedford incremental loading training. The rats were divided into three groups, control group (C), immediately after training group (IT), rest 3 hours after training group (RT). Then using high performance liquid chromatography (HPLC) to detect the concentration of neurotransmitter in spinal cord. RESULTS: Amino acid neurotransmitters in spinal cord increased in IT group: Glu, GABA increased significantly (P < 0.05), Gly also increased but have no statistic difference; while in RT group, amino acid neurotransmitters got back to normal. However monoamine neurotransmitters NE, 5-HT tended to decrease in IT group. In RT group 5-HT decreased dramatically (P < 0.05). CONCLUSION: Exercise-induced fatigue changed the concentration of neurotransmitter in spinal cord.The results suggested that neurotransmitter in spinal cord might have relationship with exercise-induced fatigue, especially 5-HT might have more important effect on recovery of fatigue.