Animals ; Biological Transport, Active/physiology* ; Centrioles/metabolism* ; Cilia/metabolism* ; Mice ; Mice, Mutant Strains ; N-Acetylglucosaminyltransferases/metabolism*

The ionic quantity across the channel of the cell membrane decides the cell in a certain life state. The theory analysis that existed on the bio-effects of the electro-magnetic field (EMF) does not unveil the relationship between the EMF exerted on the cell and the ionic quantity across the cell membrane. Based on the cell construction, the existed theory analysis and the experimental results, an ionic probability wave theory is proposed in this paper to explain the biological window-effects of the electromagnetic wave. The theory regards the membrane channel as the periodic potential barrier and gives the physical view of the ion movement across cell-membrane. The theory revises the relationship between ion's energy in cell channel and the frequency exerted EMF. After the application of the concept of the wave function, the ionic probability across the cell membrane is given by the method of the quantum mechanics. The numerical results analyze the physical factors that influences the ion's movement across the cell membrane. These results show that the theory can explain the phenomenon of the biological window-effects.
Animals ; Biological Transport, Active ; Cell Membrane ; physiology ; radiation effects ; Cell Membrane Permeability ; physiology ; radiation effects ; Computer Simulation ; Electromagnetic Fields ; Ion Channels ; metabolism ; Ions ; metabolism ; Models, Biological

OBJECTIVE: To explore the interaction between arginine functionalized hydroxyapatite (HAP/Arg) nanoparticles and endothelial cells, and to investigate mechanisms for endocytosis kinetics and endocytosis.
 METHODS: Human umbilical vein endothelial cells (HUVECs) were selected as the research model.Cellular uptake of HAP/Arg nanoparticles were observed by laser scanning confocal microscopy.Average fluorescence intensity of cells after ingestion with different concentrations of HAP/Arg nanoparticles were determined by flow cytometer and atomic force microscopy.
 RESULTS: The HAP/Arg nanoparticles with doped terbium existed in cytoplasm, and most of them distributed around the nucleus area after cellular uptake by HUVECs. Cellular uptake process of HAP/Arg nanoparticles in HUVECs was in a time and concentration dependent manner. 4 h and 50 mg/L was the best condition for uptake. HAP/Arg nanoparticles were easier to be up-taken into the cells than HAP nanoparticles without arginine functionalized.
 CONCLUSION HAP/Arg nanoparticles are internalized by HUVECs cells through an active transport and energy-dependent endocytosis process, and it is up-taken by cells mainly through caveolin-mediated endocytosis, but the clathrin-dependent endocytic pathway is also involved..
Arginine ; pharmacology ; Biological Transport, Active ; physiology ; Caveolins ; physiology ; Cells, Cultured ; Clathrin ; physiology ; Durapatite ; pharmacokinetics ; Endocytosis ; physiology ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Nanoparticles ; metabolism

Amyotrophic Lateral Sclerosis ; genetics ; Animals ; Biological Transport, Active ; Bipolar Disorder ; genetics ; Glucose Transporter Type 4 ; metabolism ; Hepacivirus ; physiology ; Humans ; Neoplasm Metastasis ; Neoplasms ; metabolism ; Point Mutation ; Polymorphism, Single Nucleotide ; R-SNARE Proteins ; metabolism ; Tissue Distribution ; Transport Vesicles ; physiology ; Vesicular Transport Proteins ; chemistry ; genetics ; metabolism ; physiology ; Virus Replication

Experiments were performed to study the relationship between presynaptic calcium and miniature inhibitory postsynaptic currents (mIPSCs) using voltage-clamp technique with whole cell mode in Xenopus optic tectal slices. The results are as follows: The frequency of mIPSCs decreased from 1.91+/-0.59 Hz to 0.34+/-0.09 Hz in calcium-free solution (paired t test, P=0.019, n=8), the value of mIPSCs frequency being (25.5+/-4.4)% of control. In order to rule out the effect of remaining calcium in perfusing solution we further applied calcium-free solution containing egtazic acid, ethyleneglycol-bis (beta-aminoethylether)-N,N -tetraacetic acid (EGTA) (200 nmol/L-2 mmol/L). The mIPSCs frequency changed from 1.57+/-0.57 in control to 0.89+/-0.41 Hz in calcium-free solution containing EGTA (paired t test, P=0.002, n=12), decreasing to (40.0+/-5.9)% of control. There is no statistical difference in the results between Ca(2+)-free perfusion and Ca(2+)-free solution containing EGTA (paired t test, P=0.74, n=9). When cadmium chloride (CdCl2, 100 micromol/L), a non-specific Ca(2+) channel blocker, was applied to the bath solution, the mIPSCs frequency decreased from 1.15+/-0.34 Hz in control to 0.25+/-0.09 Hz in CdCl2-containing solution (paired t test, P=0.008, n=11), reaching (29.25+/-6.1)% of control. However, the amplitude did not change much. An endoplasmic reticulum pump inhibitor thapsigargin increased the mIPSCs frequency from 0.93+/-0.19 Hz to 1.58+/-0.28 Hz (paired t test, P=0.002, n=11). The value in the latter is (214.6 +/-49.1)% of that in the former. In order to exclude the remaining calcium from the bathing solution, the mIPSCs frequency was first recorded from calcium-free solution as control (0.41+/-0.08 Hz) and then from calcium-free containing TG solution (8-16 micromol/L)(0.71+/-0.15 Hz)(paired t test, P=0.026, n=5), increasing to (175.0+/-14.6)% of control. The endoplasmic reticulum Ca(2+) store RyR agonist (ryanodine, 10-100 nmol/L) enhanced mIPSCs frequency from 1.18+/-0.40 Hz to 1.80+/-0.44 Hz with increment of (261.8+/-89.5)% (paired t test, P=0.004, n=6). However, the endoplasmic reticulum RyR antagonist (procaine, 2 mmol/L) could inhibit mIPSCs from 1.26+/-0.35 Hz to 0.43+/-0.15 Hz (paired t test, P=0.027, n=6). U73122 (40 micromol/L), a phosphalipase C inhibitor, decreased also mIPSCs frequency from 2.01+/-0.58 Hz in control to 0.92+/-0.40 Hz in U73122-containing solution (paired t test, P=0.002, n=10). Caffeine (10 mmol/L) markedly diminished mIPSCs frequency from 3.22+/-0.64 Hz to 0.15+/-0.30 Hz (paired t test, P=0.003, n=7), which is (4.6+/-2.9)% compared to control. Furthermore, in some cases the caffeine could abolish mIPSCs. Taken together, our results demonstrated that cytosolic calcium might be important for mediating the generation of mIPSCs. The cytosolic calcium could be increased by calcium influx through membrane calcium channel on presynaptic membrane, and/or by calcium released through RyR and IP(3)R in presynaptical internal store. The increased cytosolic Ca(2+) both from external solution or internal Ca(2+) stores might increase the transmitter vesicles at the presynaptic terminal, which in turn results in the increase of the mIPSCs frequency in the postsynaptic neurons.
Animals ; Biological Transport, Active ; Calcium ; physiology ; Calcium Channels ; metabolism ; physiology ; Electrophysiology ; Extracellular Space ; metabolism ; Inositol 1,4,5-Trisphosphate Receptors ; Neurons ; physiology ; Patch-Clamp Techniques ; Presynaptic Terminals ; physiology ; Receptors, Cytoplasmic and Nuclear ; metabolism ; Ryanodine Receptor Calcium Release Channel ; metabolism ; Synapses ; physiology ; Synaptic Transmission ; physiology ; Xenopus

The organic anion transporters (OAT) have recently been identified. Although the some transport properties of OATs in the kidney have been verified, the regulatory mechanisms for OAT's functions are still not fully understood. The rat OAT1 (rOAT1) transports a number of negatively charged organic compounds between the cells and their extracellular milieu. Caveolin (Cav) also plays a role in membrane transport. Therefore, we investigated the protein-protein interactions between rOAT1 and caveolin-2. In the rat kidney, the expressions of rOAT1 mRNA and protein were observed in both the cortex and the outer medulla. With respect to Cav-2, the expressions of mRNA and protein were observed in all portions of the kidney (cortex < outer medulla = inner medulla). The results of Western blot analysis using the isolated caveolae-enriched membrane fractions or the immunoprecipitates by respective antibodies from the rat kidney showed that rOAT1 and Cav-2 co-localized in the same fractions and they formed complexes each other. These results were confirmed by performing confocal microscopy with immunocytochemistry using the primary cultured renal proximal tubular cells. When the synthesized cRNA of rOAT1 along with the antisense oligodeoxynucleotides of Xenopus Cav-2 were co-injected into Xenopus oocytes, the [14C]p-aminohippurate and [3H]methotrexate uptake was slightly, but significantly decreased. The similar results were also observed in rOAT1 over-expressed Chinese hamster ovary cells. These findings suggest that rOAT1 and caveolin-2 are co-expressed in the plasma membrane and rOAT1's function for organic compound transport is upregulated by Cav-2 in the normal physiological condition.
Animals ; Biological Transport, Active/*physiology ; CHO Cells ; Caveolins/*metabolism ; Cell Membrane/*metabolism ; Cells, Cultured ; Hamsters ; Immunoprecipitation ; Kidney Tubules, Proximal/*metabolism ; Methotrexate/metabolism ; Microscopy, Confocal ; Oligonucleotides, Antisense/pharmacology ; Oocytes/metabolism ; Organic Anion Transport Protein 1/antagonists & inhibitors/genetics/*metabolism ; RNA, Complementary/metabolism ; RNA, Messenger/genetics/metabolism ; Rats ; Research Support, Non-U.S. Gov't ; Xenopus laevis/metabolism ; p-Aminohippuric Acid/metabolism

The cardiac electrophysiological effects of capsaicin (CAP) were examined in guinea pig papillary muscles using intracellular microelectrode technique. The results obtained are as follows: (1) the duration of action potential (APD) in normal papillary muscles was decreased by CAP (30, 60, 120 micromol/L) in a concentration-dependent manner; (2) in partially depolarized papillary muscles, 60 micromol/L CAP not only reduced APD, but also decreased the amplitude of action potential, overshoot and maximal velocity of phase 0 depolarization; (3) pretreatment with L-type Ca(2+) channel agonist Bay K8644 (0.5 micromol/L) could completely block the effects of CAP (60 micromol/L); (4) pretreatment with ruthenium red (20 micromol/L), a vanilloid receptor (VR) blocker, did not affect the actions of capsaicin on papillary muscles. All these results suggest that the effects of CAP on papillary muscles are likely due to a decrease in calcium influx which is not mediated by VR.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester ; pharmacology ; Action Potentials ; drug effects ; Animals ; Biological Transport, Active ; Calcium Channel Agonists ; pharmacology ; Calcium Channels, L-Type ; Capsaicin ; pharmacology ; Female ; Guinea Pigs ; Male ; Microelectrodes ; Papillary Muscles ; physiology ; Receptors, Drug ; antagonists & inhibitors ; Ruthenium Red ; pharmacology