ABSTRACT
BACKGROUND: We have previously reported that marine algae polysaccharide derivant can significantly promote bone cell growth.OBJECTIVE: To observe the effect of marin algae polysaccharide derivant in treatment of osteoporosis.METHODS: Sixty female Wistar rats were randomly divided into control group, treatment group and model group. There were 20 rats in each group. The rats in treatment group and model group were respectively treated with retinoic acid to induce osteoporosis. The rats in treatment group were gavaged the marine algae polysaccharide derivant 10 mg/kg, and the rats in model group were gavaged the glucose 10 mg/kg orally for 14 days. Changes of rat femur bone histological examination and histomorphometry parameters were observed.RESULTS AND CONCLUSION: The mean Trabecular Number (Tb.N), the mean Trabecular Thickness (Tb.Th) and the percent Trabecular Area (Tb.Ar%) were significantly decreased in the model group compared with control group. The mean trabecular separation (Tb.Sp) was greatly increased. After intake of marine algae polysaccharide derivant, Tb.N, Tb.Th and Tb.Ar% of the treatment group were significantly more than that of the model group. The Tb.Sp was obviously reduced. These indicate that marine algae polysaccharide derivant can increase bone mass and have a therapeutic and preventional effect on the osteoporosis.
ABSTRACT
Objective To research the mechanism or pathway through which Substance P(SP) inhibits r-aminobutyric acid(GABA) activated currents in bullfrog dorsal root ganglion(DRG) neurons.Method The experiment was conducted on freshly isolated bullfrog dorsal root ganglion neurons using a whole-cell patch-clamp technique.Results SP could caused a slow inward current when SP was applied to DRG neurons;SP could inhibits GABA-activated currents;The inhibition could be reduced largely when protein kinase C(PKC) inhibiter,1-(5-isoquinolinesulphorry)-2-methylpiperazine(H-7), was dialyzed in cell body.Conclusion The SP ton inhibit GABA-activated currents through protein kinase C.
ABSTRACT
Objective:To explore the role of reactive oxygen species(ROS,i.e,H_2O_2 and O_2-) in regulation of respiratory rhythm in the medial area of nucleus retrofacialis(mNRF).Methods: Medullary slices of neonatal SD rats,including hypoglossal nerve(Ⅻn) and mNRF,were made according to Suzue's method.Simultaneous recording of the Ⅻn respiratory rhythmic activity(RRA) with suction electrode and the respiratory neuronal discharge were performed with whole cell patch in the mNRF on the brainstem slice in vitro.The effect of t-butyl hydroperoxide(tBHP) and ?-lipoic acid(?-LA) on the respiratory pacemaker neurons and respiratory rhythm in the mNRF were observed.Results: tBHP significantly decreased respiratory cycle(RC) and increased respiratory amplitude;?-LA significantly increased RC and decreased its amplitude.Meanwhile,?-LA significantly prolonged the action potential of the respiratory cadmium-insensitive pacemaker neurons and reduced its amplitude,but it had no significant effect on the cadmium-sensitive respiratory pacemaker neurons.Voltage steps and ramps showed that ?-LA inhibited both the transient and persistent sodium current of cadmium-insensitive pacemaker neurons.Conclusion: ROS has an excitatory effect on the respiratory rhythm and the cadmium-insensitive respiratory pacemaker neurons through modulating sodium current.