Intracellular Ca2+ mobilization in neuro-skeletal muscle synapse was studied by measuring Ca2+-aequorin luminescence transients (Ca2+ transients). Ca2+ transients were categorized into three groups as follows : (1) The 1st phase of rapid Ca2+ mobilization was accompanied with twitch tension, (2) the 2nd phase of slow Ca2+ mobilization was not accompanied with twitch tension, and only observed in the presence of cholinesterase inhibitors, and (3) the 3rd phase was spontaneous Ca2+ mobilization which was rather related to contracture. The caffeine effects were composed of 1st phase-potentiation (cyclic AMP increase?), 2nd phase-inhibition (n-acetylcholine receptor (AChR) closely related), and the increase of 3rd phase (Ca2+ release from salcoplasmic reticulum). d-Tubocurarine showed much higher potency for the inhibition of the 2nd phase than for that of the 1st phase. These results suggest that the 1st phase Ca2+ transients are related to T-type n-AChR channel, whereas the 2nd phase Ca2+ transients are related to S-type n-AChR channel and its mediated signal transduction.
Effects of a 70% methanolic extract (E-S) from the dried leaves of Epimedium sagittatum on a phagocytic activity of reticuloendothelial system were studied by the carbon clearance method in mice. The clearance-rate of carbon significantly increased 1 h after the oral administration of E-S (200 or 500 mg/kg, one time/d for 5d). E-S activated the phagocytosis of carbon by Kupffer cells in the liver. Icariin and epimedin C isolated from E-S also activated the phagocytosis. These results suggest that E-S promotes the phagocytic activity of the reticuloendothelial system in mice and has a stimulatory effect on macrophage.
Effects of cepharanthine, one of membrane-stabilizing agents, on membrane permeability and on liposomal size were examined. When cepharanthine was added to the lipid before liposome formation, the size of liposome increased and the permeability did not change. On the other hand, when cepharanthine was added to the liposome suspension after liposome formation, no effect was found on liposomal size but the membrane permeability increased and lag time of initial leak of 5 (& 6)-carboxyfluorescein reduced dosedependently.
In designing the dosage form, one major factor controling their physicochemical properties is solid forms of the drug powder. The method for improving the physicochemical stability of unstable β-lactam antibiotics is very important. E1040 is a novel parenteral 3-betaine type cephalosporin which has a broad antibacterial spectrum and potent activities against Citrobacter, freundii, Enterobacter cloacase, and glucose-nonfermentative bacteria, including P. aeruginosa. The present study was intended to provide the solid-state chemical stability of perenteral steril dry dosage form of E1040. The chemical stability differences among the various solid forms, dry amorphous, additive freeze dried amorphous solid and crystalline powder, were evaluated as a function of temperature by thermo stress tests. Freeze dried anhydrous amorphous form was the first steril dry dosage form investigated during the preformulation study. However, this compound is chemically unstable, in the titer of them, reduction are observed in the freeze dried amorphous solid. In order to select the most suitable solid form of E1040, two methods were used. One was crystalline solid and the other was NaCl additive freezedried formulation. Through our experiments, the solid-state chemical stabilization can be achieved by these two methods (effect of crystal structure and effect of NaCl additive).
An X-ray diffraction methods and Fourier transform infrared analysis with photoacoustic detector (FTIR-PAS) for estimation of the degree of crystallinity of crystalline E1040 formulation was established. The X-ray procedure to determine the crystallinity of E1040 was based upon the measurement of the total scattering and the scattering from the crystalline region of the drug. The FTIR-PAS procedures are based upon the measurement of the peak height ratio at 1628 cm-1 and measurement of the spectral region between 2400 and 3700 cm-1 by the Partial least squares (PLS) techniques. The data of the degree of crystallinity from the X-ray diffraction methods are consistent with the data from FTIR-PAS methods. The increase of the degree of crystallinity of the drug formulation decreased the decomposition rate of E1040. As a result, it had become apparent that two analytical procedures were actually valid. This assured optimizing process conditions which affect the improvement of crystallinity.
The effects of various nucleic acid constitutional compounds, base, nucleoside and nucleotide on lethality and skin injury induced by soft X-irradiation were studied. The survival effect was determined by use of survival days after irradiation of lethal dose of 70 kVp, 2100R and the protective effect on skin injury was determined by use of degrees on skin injury after 30 kVp, 1100R soft X-irradiation. As a result of these studies, the survival effect was observed by single injection of inosine at 120, 60 and 5 min before irradiation and three times injection after irradiation. And the other nucleic acid constitutional compounds had no effect on survival. Protective effect of skin injury was observed by single injection of adenosine, guanosine, inosine, 5'-adenosine monophosphate (5'-AMP), 5'-guanosine monophosphate (5'-GMP) and 5'-inosine monophosphate (5'-IMP) before irradiation. Protective effect of skin injury by three time injection before irradiation were revealed in adenosine, inosine, 5'-AMP and 5'-IMP. For the investigation of superoxide anions and hydroxyl radicals scavenge activities, the relationship between radical scavenge activities and protective effect of radiation by using various nucleosides was not observed.
In order to investigate useful protective medicines for the relief of skin injury induced by irradiation, 60 methanol extracts of Chinese traditional medicines were used in the test of protective potency on skin injury. ICR male mice at 6 weeks of age were whole-body irradiated with 1100R by using a soft X-ray generator (30 kVp, 10 mA, 190 R/min). Each methanol extract of these medicines was injected intraperitoneally into mice before or after irradiation. The degrees of skin injury were determined by a score system of skin reaction within the observation period from 21st to 40th day after irradiation. Protective potency of each medicine on skin injury was calculated from the maximum mean scores of administrated group and un-administrated group. As a result of these studies, the protective potency was detected in Unsei-in, Kumi-binro-to, Keisi-syakuyaku-chimo-to, Keigai-rengyo-to, Gosyuyu-to, Koso-san, Saiko-seikan-to, Syo-kankyo-to, Syo-saiko-to, Syoma-kakkon-to, Sen-kan-meimoku-to, Zokumei-to, Sokei-kakketu-to, Bokuryo-in, Mao-to and Rikkunsi-to by intraperitoneal injection before irradiation. Of these effective medicines, only Unsei-in and Mao-to are shown to have a significant protective effect by intraperitoneal injection after irradiation.
The effects of levocarnitine chloride [LC-80, (-)-(R)-(3-carboxy-2-hydroxypropyl)-trimethylammonium chloride] on the oxidation of [U-14C] palmitate, [U-14C] glucose and [2-3H] glucose under hypoxic conditions in homogenates from the rat heart were investigated. LC-80 at concentrations of 0.5 and 1.0 mM caused significant and concentrationdependent increases in the depressed 14CO2 production from [U-14C] palmitate or [U-14C]-glucose oxidation under hypoxia up to 50 min after the addition of LC-80. In contrast, a marked increase in 3H2O production from [2-8H] glucose oxidation under hypoxia was observed, and LC-80 at concentrations of 0.5 and 1.0 mM caused further significant and concentration-dependent enhancement of 3H2O production up to 50 min after the addition of LC-80. Moreover, LC-80 at a concentrations of 1.0 mM significantly restored the marked depression of pyruvate dehydrogenase complex activity and mitochondrial respiratory function under hypoxia. These results suggested that LC-80 has an improving effect on myocardial metabolism under ischemia by enhancing fatty acid and glucose metabolisms.