OBJECTIVETo investigate the vasodilating effects of pethidine, particularly in association with intracellular calcium.

METHODSAorta rings of Sprague-Dawley rats, with or without endothelium, were prepared in organ bath to measure the vascular tone. Pre-contractions by KCl (80 mmol/L) and phenylephrine (PhE) (10(-6)mol/L) were induced.

RESULTSPethidine did not alter the resting tension of aorta rings, but produced dose-dependent relaxation in KCl and PhE pre-treated aorta rings with or without endothelium. Pethidine did not change the caffeine-stimulated contraction, and still had similar inhibition in KCl pre-contracted aorta rings after pretreatment with ruthenium red. Pethidine decreased the contractile responses induced by PhE in Ca(2+)-free solution or by adding calcium into Ca(2+)-free solution.

CONCLUSIONPethidine could produce an endothelium-independent vasodilatation in KCl and PhE pre-contracted aorta rings, which is related to inhibition of Ca(2+)entry and IP3-sensitive Ca(2+) release in vascular smooth muscle.

Animals ; Caffeine ; pharmacology ; Calcium ; metabolism ; Male ; Meperidine ; pharmacology ; Potassium Chloride ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Vasodilator Agents ; pharmacology

OBJECTIVETo compare the effect of Acanthopanacis senticosi injection, theophylline and caffeine on human sperm mobility in vitro.

METHODSWe incubated the sperm aseptically obtained by masturbation from 12 asthenospermia men and treated by swim-up technique in Acanthopanacis senticosi injection (10 g/L), theophylline (3 mmol/L) and caffeine (7 mmol/L) respectively, and detected various sperm parameters with the computer-assisted sperm analysis (CASA) system at 0 h, 1 h and 3 h.

RESULTSAcanthopanacis senticosi injection significantly increased sperm motility, the percentage of progressive motile sperm, straight line velocity (VSL) and curvilinear velocity (VCL) as compared with theophylline and caffeine (P < 0.05).

CONCLUSIONAcanthopanacis senticosi injection can activate the mobility of human sperm in vitro.

Caffeine ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Eleutherococcus ; chemistry ; Humans ; In Vitro Techniques ; Male ; Sperm Motility ; drug effects ; Theophylline ; pharmacology

In the present study, the intracellular free calcium concentration ([Ca(2+)](i)) in acutely isolated rat dorsal root ganglia (DRG) neurons modulated by loureirin B, an active component of "dragon's blood" which is a kind of Chinese herbal medicine, was determined by the means of Fura-2 based microfluorimetry. It was found that loureirin B could evoke the elevation of [Ca(2+)](i) in a dose-dependent manner. However, the elevation of [Ca(2+)](i) evoked in the calcium free solution was much smaller than that in the standard external cell solution, suggesting that most change of [Ca(2+)](i) was generated by the influx of extracellular Ca(2+), not by the activities of intracellular organelles like Ca(2+) stores and mitochondria. In addition, the mixture of loureirin B and caffeine also induced [Ca(2+)](i) rise, but the peak of [Ca(2+)](i) rise induced by the mixture was significantly lower than that by caffeine alone, which means the triggering pathway and the targets of caffeine are probably involved in loureirin B-induced [Ca(2+)](i) rise. Moreover, compared to the transients induced by caffeine, KCl and capsaicin, the loureirin B-induced [Ca(2+)](i) rise is much slower and more stable. These results indicate that the capability of loureirin B of inducing the [Ca(2+)](i) rise is solid and unique.
Animals ; Caffeine ; pharmacology ; Calcium ; metabolism ; Ganglia, Spinal ; drug effects ; metabolism ; Neurons, Afferent ; drug effects ; metabolism ; Rats ; Resins, Plant ; pharmacology

OBJECTIVETo compare the behavioral effects of psychoactive drugs between two strains of mice.

METHODSThe Kunming (KM) and ICR mice were injected intraperitoneally with caffeine (3, 10, 30, 100 mg/kg), ephedrine (3, 10, 30, 100 mg/kg), diazepam (1, 3,1 0 mg/kg) and chloral hydrate (10, 30, 100 mg/kg), respectively. Ten min after injection, the locomotor activity in the open field was recorded for 2 h. The total distance, the distance ratio to total distance and the time in central region were analyzed for each drugs. Thirty min after injection, the latent time in the passive avoidance test was measured in a shuttle box.

RESULTSCaffeine and diazepam prolonged the latent time, and ephedrine and chloral hydrate decreased the latent time, but there were no differences between the two strains. The two strains of mice exhibited significant differences in the total distance after injection of ephedrine 10 mg/kg, diazepam 3 mg/kg and chloral hydrate 100 mg/kg. Compared to KM mice, ICR mice exhibited an increase in the distance ratio and the time in central region after injection of ephedrine 10-100 mg/kg, but a decrease after diazepam 3-10 mg/kg.

CONCLUSIONKM and ICR mice show no differences in latent time, but significant differences in the total distance, the distance ratio and the time in central region in the locomotor activity. Therefore, selection of mouse strains is important in the study of psychoactive drugs.

Animals ; Caffeine ; pharmacology ; Central Nervous System Agents ; pharmacology ; Chloral Hydrate ; pharmacology ; Diazepam ; pharmacology ; Dose-Response Relationship, Drug ; Ephedrine ; pharmacology ; Mice ; Mice, Inbred ICR ; Motor Activity ; drug effects

Action Potentials ; Animals ; Bufo bufo ; Caffeine ; pharmacology ; Female ; Heart ; drug effects ; physiology ; In Vitro Techniques ; Male ; Sciatic Nerve ; physiology

OBJECTIVETo investigate the effect and mechanism of Huanglian Jiedu Tang active fraction (HIJDTAF) on calcium overloading in neurons.

METHODCerebral ischemia was imitated by hypoxia/hypoglycemia damage on fetal rat neurons. Double wavelength fluorospectrophotometry was used to assay the content of calcium in neurons in order to evaluate the effect of HLJDTAF on calcium overloading. Neurons were treated with glutamic acid, potassium chloride (KCl), A23187, caffeine(CAF) and methacholine (Mch) to analysis the related mechanism of HLJDTAF on calcium overloading in neurons.

RESULTHLJDTAF 0.3, 0.15 g x k(-1) could remarkably inhibit the calcium overloading in neurons caused by hypoxia/hypoglycemia, glutamic acid, KCl and A23187. HLJDTAF 0.3 g x kg(-1) could inhibit the increasing of calcium caused by CAF and Mch in the presence of and in the absence of extra-calcium.

CONCLUSIONHLJDTAF could remarkably inhibit the calcium overloading in neurons after cerebral ischemia injury, it probably plays the function via several pathways.

Animals ; Caffeine ; pharmacology ; Calcimycin ; pharmacology ; Calcium ; metabolism ; Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; Glutamic Acid ; pharmacology ; Male ; Methacholine Chloride ; pharmacology ; Neurons ; cytology ; drug effects ; metabolism ; Potassium Chloride ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Spectrometry, Fluorescence

Caffeine,as an important component of refreshment beverage,has been used for a long history. In recent years,its effect on pain relief has been widely explored. As one of nonselective adenosine receptor blockers,caffeine plays different roles in the central and peripheral pain. This review explores the roles of caffeine in acute and chronic pain and the potential mechanisms.
Adenosine ; antagonists & inhibitors ; metabolism ; Caffeine ; pharmacology ; therapeutic use ; Central Nervous System Stimulants ; pharmacology ; therapeutic use ; Chronic Pain ; drug therapy ; Humans ; Pain ; drug therapy

AIMTo study whether store-operated Ca2+ channel (SOC) is present in rat colonic smooth muscle cells.

METHODSIntracellular Ca2+ ([Ca2+]i) changes induced by thapsigargin- or caffeine-activated SOC channel were measured in enzymatically dissociated rat colonic smooth muscle cells with the fluorescent indicator Fura-2/AM.

RESULTSIn the absence of external Ca2+ , the sarco-endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (1 micromol/L) and ryanodine receptor (RyR) activator caffeine both transiently elevated [Ca2+]i from (68.32 +/- 3.43) nmol/L to (240.85 +/- 12.65 ) nmol/L, (481.25 +/- 34.77) nmol/L. A subsequent reintroduction of Ca2+ into the extracellular solution resulted in [Ca2+]i further elevated to (457.55 +/- 19.80) nmol/L, (1005.93 +/- 54.62) nmol/L; (643.88 +/- 34.65) nmol/L, (920.16 +/- 43.25) nmol/L, respectively. And the elevated response was blocked by lanthanum (1 mmol/L), but was insensitive to L-type voltage calcium channels blocker verapamil and membrane depolarization.

CONCLUSIONSOC activated by store depletion are present in rat colonic smooth muscle cells. And we further prove the existence of such Ca2+ channels in excitable cells.

Animals ; Caffeine ; pharmacology ; Calcium ; metabolism ; Calcium Channels ; physiology ; Colon ; cytology ; Fura-2 ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Rats ; Rats, Wistar ; Thapsigargin ; pharmacology

BACKGROUNDPreconditioning with remifentanil confers cardioprotection. Since Ca(2+) overload is a precipitating factor of injury, we determined the effects of remefentanil on intracellular Ca(2+) ([Ca(2+)](i)) and its transients induced by electrical stimulation and caffeine, which reflects Ca(2+) handling by Ca(2+) handling proteins, in rat ventricular myocytes.

METHODSFreshly isolated adult male Sprague-Dawley rat myocytes were loaded with Fura-2/AM and [Ca](i) was determined by spectrofluorometry. Remifentanil at 0.1 - 1000 microg/L was administered. Ten minutes after administration, either 0.2 Hz electrical stimulation was applied or 10 mmol/L caffeine was added. The [Ca(2+)](i), and the amplitude, time resting and 50% decay (t(50)) of both transients induced by electrical stimulation (E [Ca(2+)](i)) and caffeine (C [Ca(2+)](i)) were determined.

RESULTSRemifentanil (0.1 - 1000.0 microg/L) decreased the [Ca(2+)](i) in a dose-dependent manner. It also decreased the amplitude of both transients dose-dependently. Furthermore, it increased the time to peak and t(50) of both transients dose-dependently.

CONCLUSIONRemifentanil reduced the [Ca(2+)](i) and suppressed the transients induced by electrical stimulation and caffeine in rat ventricular myocytes.

Animals ; Caffeine ; pharmacology ; Calcium ; metabolism ; Calcium Signaling ; drug effects ; Cells, Cultured ; Electric Stimulation ; Male ; Myocytes, Cardiac ; drug effects ; metabolism ; Piperidines ; pharmacology ; Rats ; Rats, Sprague-Dawley

The threshold of cyclin E expression at G1/S boundary is a characteristic feature of cell cycle progressing. In this study, we tried to develop a quantitative approach to analyze cyclin E threshold by multiparameter flow cytometry. The expression of cyclin E in exponentially growing MOLT-4 cells was detected under different photomultiplier tube (PMT) voltages by cyclin E/DNA multiparameter flow cytometry. Additionally, cyclin E was detected in cells which were treated with caffeine and cycloheximide (CHX) under the same PMT voltage. Moreover, the expression of cyclin E in MOLT-4 cells was compared with that in JURKAT cells. Cyclin E threshold was quantified by formula B2/AxC (A, B, C indicates the minimum, threshold, and maximum of cyclin E fluorescence intensity, respectively). Results showed that in MOLT-4 cells, cyclin E threshold calculated by formula B2/AxC was invariable under different PMT settings. It was decreased in cells treated with caffeine and remained changeless in cells treated with cycloheximide. Cyclin E threshold in JURKAT cells was much lower than that in MOLT-4 cells. It was suggested that Formula B2/AxC we firstly set up could be used to analyze cyclin E expression threshold quantitatively.
Caffeine/pharmacology ; Cell Cycle/*physiology ; Cell Line, Tumor ; Cyclin E/*analysis ; Cycloheximide/pharmacology ; DNA, Neoplasm/*analysis ; Flow Cytometry/methods ; Jurkat Cells ; Leukemia, Lymphoid/pathology