No abstract available.
Ethanol*

There is nothing that is harmless ; the dose alone decides that something is no poison(Paracelsus. 1493-1541). So, in a point of view to maximize the therapeutic efficacy of drug therapy in a was that minimize the drug toxicity, the knowledges of the drug-interactions as well as the pharmacokinetic and pharmacodynamic principles of every therapeutic drug used in the medical clinic cannot be emphasized too much. Many drug interactions can be predicted if the pharmacokinetic properties, pharmacodynamic mechanisms of action of the interacting drugs are known and most adverse interactions can be avoided. In this paper, the clinical importance, classification, and general principles of clinical drug-interactions are presentated with a few explanatory examples.
Classification ; Drug Interactions* ; Drug Therapy ; Drug-Related Side Effects and Adverse Reactions

No abstract available.
Animals ; Brain Stem* ; Brain* ; Electroshock* ; Hypothalamus* ; Mice*

Interactions among dexamethasone, dehydroepiandrosterone (DHEA), lipopolysaccharide (LPS), and antimycin A on the glutamate uptake and the polyamine uptake were investigated in primary cultures of rat cerebral cortical astrocytes to examine the effects of dexamethasone and DHEA on the regulatory role of astrocytes in conditions of increased extracellular concentrations of glutamate or polyamines. 1. (3H)Glutamate uptake: LPS and antimycin A decreased Vmax, but both drugs had little effect on Km. Dexamethasone also decreased basal Vmax without any significant effect on Km. And dexamethasone further decreased the antimycin A-induced decrease of Vmax. DHEA did not affect the kinetics of basal glutamate uptake and the change by LPS or antimycin A. 2. (14C)Putrescine uptake: LPS increased Vmax, and antimycin A decreased Vmax. They showed little effect on Km. Dexamethasone decreased Vmax of basal uptake and further decreased the antimycin A-induced decrease of Vmax, and also decreased Vmax to less than control in LPS-treated astrocytes. DHEA did not affect Km and the change of Vmax by LPS or antimycin A. 3. (14C)Spermine uptake: Antimycin A decreased Vmax, and LPS might increase Vmax. Km was little affected by the drugs. Dexamethasone decreased basal Vmax and might further decrease the antimycin A-induced decrease of Vmax. And dexamethasone also decreased Vmax to less than control in LPS-treated astrocytes. DHEA might increase basal Vmax and Vmax of LPS-treated astrocytes. 4. Vmax of glutamate uptake by astrocytes was increased by putrescine (1000 muM & 2000 muM) and spermidine (200 muM, 500 muM & 2000 muM). Spermine, 200 muM (and 100 muM), also increased Vmax, but a higher dose of 2000 muM decreased Vmax. Km of glutamate uptake was not significantly changed by these polyamines, except that higher doses of spermine showed tendency to decrease Km of glutamate uptake. In astrocytes, dexamethasone inhibited the glutamate uptake and the polyamine uptake in normal or hypoxic conditions, and the polyamine uptake might be stimulated by LPS and DHEA. Polyamines could aid astrocytes to uptake glutamate.
Animals ; Antimycin A* ; Astrocytes* ; Dehydroepiandrosterone* ; Dexamethasone* ; Glutamic Acid* ; Kinetics ; Polyamines ; Putrescine ; Rats* ; Spermidine ; Spermine

The prevalence of obesity is rapidly growing throughout the developing and developed world. Given the seriousness of obesity, it critically needs to develop new therapeutic ways to defend against its growth. Persistent increase in food intake is a primary cause of the energy imbalance. The arcuate nucleus of the hypothalamus is a key region to integrate signals originating from various regions in periphery and leptin resistance in the central nervous system (CNS) contributes to the impaired regulation of food intake. It has been endeavor to treat obesity by understanding the mechanisms of CNS regulation of food intake. Adipose tissue has been regarded as a tumor because of its reversible expansibility and dependency on vasculature. There has been a challenge to starve adipose tissue by inhibiting adipose tissue vasculature. A peptide to cause apoptosis of endothelium only in white adipose tissue greatly loses body weight by reducing food intake independent of the action of leptin. This study provides convincing evidence for a previously unknown relationship between the status of adipose tissue vasculature and the regulation of food intake that may provide a novel way for decreasing body fat. However, the mechanism by which the inhibition of angiogenesis in white adipose tissue decreases food intake and body weight remains unclear. In this review, we describe the potential mechanisms of regulation of food intake induced by inhibition of angiogenesis in white adipose tissue.
Adipose Tissue ; Adipose Tissue, White ; Apoptosis ; Arcuate Nucleus ; Body Weight ; Central Nervous System ; Dependency (Psychology) ; Eating ; Endothelium ; Hypothalamus ; Leptin ; Obesity ; Prevalence

Loss of synaptic transmission and accumulation of extracellular K+((K+)o) are the key features in ischemic brain damage. Here, we examined the effects of several K+ channel modulators on the early ischemic changes in population spike (PS) and (K+)o in the CA1 pyramidal layer of the rat hippocampal slice using electrophysiological techniques. After onset of anoxic aglycemia (AA), orthodromic field potentials decreased and disappeared in 3.3 +/- 0.22 min (mean +/- SEM, n = 40). The hypoxic injury potential (HIP), a transient recovery of PS appeared at 6.0 +/- 0.25 min (n = 40) in most slices during AA and lasted for 3.3 +/- 0.43 min. (K+)o increased initially at a rate of 0.43 mM/min (Phase 1) and later at a much faster rate (12.45 mM/min, Phase 2). The beginning of Phase 2 was invariably coincided with the disappearance of HIP. Among K+ channel modulators tested such as 4-aminopyridine (0.03, 0.3 mM), tetraethylammonium (0.1 mM), NS1619 (0.3 ~ 10 muM), niflumic acid (0.1 mM), glibenclamide (40 muM), tolbutamide (300 muM) and pinacidil (100 muM), only 4-aminopyridine (0.3 mM) induced slight increase of (K+)o during Phase 1. However, none of the above agents modulated the pattern of Phase 2 in (K+)o in response to AA. Taken together, the experimental data suggest that 4-aminopyridine-sensitive K+ channels, large conductance Ca2+/-activated K+ channels and ATP-sensitive K+ channels may not be the major contributors to the sudden increase of (K+)o during the early stage of brain ischemia, suggesting the presence of other routes of K+ efflux during brain ischemia.
4-Aminopyridine ; Animals ; Brain ; Brain Ischemia ; Glyburide ; Hip ; Ischemia* ; Niflumic Acid ; Pinacidil ; Rats* ; Synaptic Transmission ; Tetraethylammonium ; Tolbutamide

The effects of DFMO or/and putrescine on the dexamethasone-induced apoptosis of CEM cells were studied to investigate the role of polyamines in anti-leukemic glucocorticoid action. Dexamethasone-induced apoptosis was preceded by significant decreases of cellular polyamine contents and putrescine uptake activity. But DFMO produced decreases of putrescine and spermidine contents and marked increase of putrescine uptake activity, but did not induce apoptosis. However, dexamethasone and DFMO, respectively, induced G|1-arrest in cell cycle and hypophosphorylation of pRb, resulting in the increase of G|1 to S ratio and decrease of CEM cell count. DFMO enhanced the dexamethasone-induced apoptosis and G|1-arrest. On the other hand, putrescine little affected the apoptotic and G|1-arresting activities of dexamethasone, but almost suppress the effects of DFMO and also the DFMO-dependent enhancement of dexamethasone effects. These results suggested that the dexamethasone-induced apoptosis to be associated with pRb hypophosphorylation and G|1-arrest in CEM cells might be ascribed to the concomitant decreases of cellular polyamine contents and putrescine uptake activity.
Apoptosis* ; Cell Count ; Cell Cycle ; Dexamethasone ; Hand ; Humans* ; Polyamines ; Putrescine ; Spermidine

The effects of crude saponin (SAP) and alkaloid (ALK) fractions of Panax ginseng C.A. Meyer on the detrimental effects of electroconvulsive shock (ECS) and scopolamine on passive avoidance response (PAR) were studied in male Sprague-Dawley rats, referring their effects on the neuronal injury and plasticity of hippocampus in response to electrolytic lesion of left entorhinal cortex (ECL). The detrimental ECS effect on PAR was attenuated by pre- and post-treatments with SAP and ALK, respectively, or by pretreatment with aminoguanidine (AG), an inhibitor of diamine oxidase and NO synthase. And the detrimental scopolamine effect on PAR was also inhibited by pretreatment with ALK or AG, and by posttreatment with SAP or ALK, respectively. On the 7th day after ECL, the brain sections stained by cresyl violet and by acetylcholinesterase (AChE) histochemistry, respectively, showed the chromatolysis and numeral decrease of neurons and the reduction of AChE reactivity in the hippocampus CA1 area and to a lesser extent, in the dentate gyrus. The neuronal cell death of the CA1 area was significantly reduced by SAP, ALK, or AG, and the reduction of AChE reactivity was significantly attenuated by SAP or ALK and to a lesser extent by AG. These results suggests that the protective effect of ginseng SAP and ALK fractions on ECS- or scopolamine-induced impairment of PAR may be ascribed in part to preservation of hippocampal neurons, particularly cholinergic neurons.
Acetylcholinesterase ; Amine Oxidase (Copper-Containing) ; Brain ; Cell Death ; Cholinergic Neurons ; Cholinesterases ; Dentate Gyrus ; Electroshock ; Entorhinal Cortex ; Hippocampus* ; Humans ; Male ; Neurons* ; Nitric Oxide Synthase ; Panax* ; Plastics ; Rats, Sprague-Dawley ; Saponins ; Scopolamine Hydrobromide ; Viola

Hepatic stellate cells (HSCs) are known to play a role in the pathogenesis of the increased intrahepatic vascular resistance found in chronic liver diseases. The aim of this study was to evaluate the K+ and Ca2+ currents in cultured HSCs from rat liver, through the patch-clamp technique. Most cells were positive for desmin immunostain after isolation and in alpha-smooth muscle actin immunostain after 10 - 14 days of culturing. Outward and inward rectifying K+ currents were confirmed. Two different types of K+ currents were distinguished: one with the inward rectifying current and the other without. The outward K+ currents consisted of at least four components: tetraethylammonium (TEA) -sensitive current, 4-aminopyridine (4-AP) -sensitive current, pimozide-sensitive current and three blocker-resistant current. The peaks of the outward K+ currents evoked by a depolarizing pulse were decreased to 32.0 +/- 3.0, 62.8 +/- 3.7 and 32.8 +/- 3.5% by 5 mM TEA, 2 mM 4-AP and 15microM pimozide, respectively. Moreover, the combined application of three blockers caused 86.6 +/- 4.8% suppression. The inward currents evoked hyperpolarizing pulses were inwardly rectifying and almost blocked by Ba2+. Elevation of external K+ increased the inward current amplitude and positively shifted its reversal potential. Voltage- dependent Ca2+ currents which were completely abolished by Cd2+ and nimodipine were detected in 14 day cultured HSCs. In this study, the cultured HSCs were found to express outward K+ currents composed of multiple pharmacological components, Ba2+-sensitive inward rectifying K+ current and L-type Ca2+ current.
Animals ; Calcium/*metabolism ; Calcium Channel Blockers/pharmacology ; Calcium Channels, L-Type/*physiology ; Cells, Cultured ; Hepatocytes/cytology/*physiology ; Immunohistochemistry ; Male ; Membrane Potentials/drug effects/physiology ; Patch-Clamp Techniques ; Potassium/*metabolism ; Potassium Channel Blockers/pharmacology ; Potassium Channels, Voltage-Gated/*physiology ; Rats ; Rats, Sprague-Dawley

We studied the sex different nicotine effect on evoked population spike amplitudes (ePSA) and connexin (Cx) expression in the hippocampus CA1 area of gerbils. Acute doses of nicotine bitartrate (0.5 mg/kg: NT-0.5) slightly reduced ePSA in males but markedly augmented that in females. Acute NT (5.0 mg/kg) markedly increased the ePSA in all gerbils. Unlike acute NT-0.5, repeated NT-0.5 injection (twice a day for 7 days) significantly increased the ePSA in males and slightly affected the NT-0.5 effect in females. The Cx36 and Cx43 expression levels as well as Cx expressing neuronal populations were significantly increased by repeated NT-0.5 in in both male and female gerbils, and particularly, Cx43 expression was somewhat prominent in females. These results demonstrated a sex difference with respect to the nicotine effect on hippocampal bisynaptic excitability, irrelevant to connexin expression.
Animals ; Connexins ; Connexin 43 ; Female ; Gerbillinae* ; Hippocampus ; Male ; Neurons* ; Nicotine* ; Sex Characteristics*