Acupuncture at “Zusanli” (St.36) and “Sanyinjiao” (SP.6) Points on the Gastrointestinal Tract: A Study of the Bioavailability of 99mTc-Sodium Pertechnetate in Rats

The objective of this study is to investigate the differences of acupuncture effect between the Zusanli (St.36) and Sanyinjiao (SP.6) points on the gastrointestinal-tract (GIT) segment performed by the bioavailability of 99mTc-sodium-pertechnetate (Na99mTcO4) in rats. Male Wistar rats (n = 21) were allocated into three groups of seven each. Group 1 was treated by acupuncture bilaterally at St.36; Group 2 at SP.6; and Group 3 was untreated (control). After 10 min of needle insertion in anesthetized rats, 0.3 mL of Na99mTcO4 (7.4 MBq) was injected via ocular-plexus. After 20 min, the exitus of animals was induced by cervical-dislocation and GIT organs isolated. However, immediately before the exitus procedure, blood was collected by cardiac-puncture for blood radio-labeling (BRL). The radioactivity uptake of the blood constituents was calculated together with the GIT organs by a well gamma counter. The percentage of injected dose per gram of tissue (%ID/g) of Na99mTcO4 was calculated for each GIT organs, while BRL was calculated in %ID. According to the one-way ANOVA, the stomach, jejunum, ileum from the treated groups (Group 1 and Group 2) had significant differences compared to the controls (Group 3). However, between the treated groups (Group 1 and Group 2), there were significant differences (P < .05) in the stomach, jejunum, ileum, cecum, transverse and rectum. In BRL analysis, Group 2 showed significant increase and decrease of the insoluble and soluble fractions of the blood cells, respectively (P < .0001). The authors suggest that St.36 may have a tendency of up-regulation effect on GIT, whereas SP.6, down-regulation effect. However, further rigorous experimental studies to examine the effectiveness of acupuncture in either acupuncture points need to be carried out

Modeling the electric potential across neuronal membranes: the effect of fixed charges on spinal ganglion neurons and neuroblastoma cells.

We present a model for the electric potential profile across the membranes of neuronal cells. We considered the resting and action potential states, and analyzed the influence of fixed charges of the membrane on its electric potential, based on experimental values of membrane properties of the spinal ganglion neuron and the neuroblastoma cell. The spinal ganglion neuron represents a healthy neuron, and the neuroblastoma cell, which is tumorous, represents a pathological neuron. We numerically solved the non-linear Poisson-Boltzmann equation for the regions of the membrane model we have adopted, by considering the densities of charges dissolved in an electrolytic solution and fixed on both glycocalyx and cytoplasmic proteins. Our model predicts that there is a difference in the behavior of the electric potential profiles of the two types of cells, in response to changes in charge concentrations in the membrane. Our results also describe an insensitivity of the neuroblastoma cell membrane, as observed in some biological experiments. This electrical property may be responsible for the low pharmacological response of the neuroblastoma to certain chemotherapeutic treatments

Relevance of Hydrodynamic Effects for the Calculation of Outer Surface Potential of Biological Membrane Using Electrophoretic Data

ABSTRACT In this paper, we present the results of a study on the influence of hydrodynamic effects on the surface potentials of the erythrocyte membrane, comparing two different models formulated to simulate the electrophoretic movement of a biological cell: the classical Helmholtz-Smoluchowski model and a model presented by Hsu et al. (1996). This model considers hydrodynamic effects to describe the distribution of the fluid velocity. The electric potential equation was obtained from the non-linear Poisson-Boltzmann equation, considering the spatial distribution of electrical charges fixed in glycocalyx and cytoplasmic proteins, as well as electrolyte charges and ones fixed on the surfaces of lipidic bilayer. Our results show that the Helmholtz-Smoluchowski model is not able to reflect the real forces responsible to the electrophoretic behavior of cell, because it does not take account the hydrodynamic effects of glycocalyx. This charged network that covers cellular surface constitutes a complex physical system whose electromechanical characteristics cannot be neglected. Then, supporting the hypothesis of other authors, we suggest that, in electrophoretic motion analyses of cells, the classical model represents a limiting case of models that take into account hydrodynamic effects to describe the velocity distribution of fluid

Sensitivity of the membrane surface potentials to charge density in the cytoplasm.

<p>Electric potentials and as a function of , as is kept constant, for the spinal ganglion neuron () and the neuroblastoma cell (). In the resting state (A), mV, for the ganglion neuron and mV, for the neuroblastoma, when (maximum values), while mV (ganglion) and mV (neuroblastoma), for (minimum). In the AP state (B), mV, for the ganglion neuron and mV, for the neuroblastoma, when (maximum), while mV (ganglion) and mV (neuroblastoma) for (minimum). In all simulations, for resting and AP states, mV, for the ganglion, and mV, for the neuroblastoma. In both graphs, .</p

Sensitivity of the membrane surface potentials to inner surface charge density.

<p>Electric potential on the surfaces of regions of the membranes of the spinal ganglion neuron () and the neuroblastoma cell (), as a function of the ratio , as is kept constant. In the resting state (A), mV, for the ganglion neuron and mV, for the neuroblastoma, when (maximum values), while mV (ganglion) and mV (neuroblastoma), for (minimum). In the AP state (B), mV, for the ganglion neuron and mV, for the neuroblastoma, when (maximum), while mV (ganglion) and mV (neuroblastoma) for (minimum). In all simulations, for resting and AP states, mV, for the ganglion, and mV, for the neuroblastoma. In both graphs, .</p

Electric potential across the membranes of spinal ganglion neurons and neuroblastoma cells, during resting state.

<p>Solutions of Eq. (52) with boundary , and Eq. (45) with boundary  =  result respectively in and , for the spinal ganglion neuron (solid), and for the neuroblastoma cell (dashed) in and . For all simulations, and .</p