Frequency-domain electricity properties of four objects, including bullfrog skin, bullfrog muscle, triply distilled water and 0.9% NaCl, were tested in the range of 100Hz-10MHz using home-made electrode and measuring system. The experimental results showed that the resistance of 0.9% NaCl decreased dramatically, that the amplitude frequency characteristics of bullfrog's muscle and skin were similar, but that of triply distilled water did not change significantly. The frequency dependence of 0.9% NaCl showed that the electrode had great influence on the measuring system, so a new equivalent circuit model based on the electrode system was needed. These findings suggest that the new five-parameter equivalent circuit model, which embodies considerations on the interaction between electrodes and tissues, is a reasonable equivalent circuit for studying the electrical characteristics of biological materials.
Animals ; Electric Capacitance ; Electric Impedance ; Electricity ; Electrodes ; Muscle, Skeletal ; physiology ; Rana esculenta ; Skin ; Sodium Chloride

The paper introduced a process to enhance the yield of Oviducts Ranae protein using in vitro enzyme hydrolysis. The treatment process included two steps: (1) a 3 - 4 h of hydrolysis of a 0.025 g x g(-1) concentration of substance, at pH 7 and 60 degrees C, using 4% of papain; and (2) followed with a 6 - 8 h hydrolysis, at pH 2 - 2.5 and 60 degrees C, using 3% of pepsin. This treatment process significantly improved the lyophilized Oviducts Ranae in solubility and fluidity, which is convenient for the relative pharmaceutical preparations.
Amphibian Proteins ; chemistry ; isolation & purification ; Animals ; Estradiol ; analysis ; Female ; Hydrogen-Ion Concentration ; Hydrolysis ; Materia Medica ; chemistry ; Oviducts ; chemistry ; Papain ; chemistry ; Pepsin A ; chemistry ; Rana esculenta