ABSTRACT
This study examined whether propofol and aminophylline affect the mobilization of intracellular calcium in human umbilical vein endothelial cells. Intracellular calcium was measured using laser scanning confocal microscopy. Cultured and serum-starved cells on round coverslips were incubated with propofol or aminophylline for 30 min, and then stimulated with lysophosphatidic acid, propofol and aminophylline. The results were expressed as relative fluorescence intensity and fold stimulation. Propofol decreased the concentration of intracellular calcium, whereas aminophylline caused increased mobilization of intracellular calcium in a concentration-dependent manner. Propofol suppressed the lysophosphatidic acid-induced mobilization of intracellular calcium in a concentration-dependent manner. Propofol further prevented the aminophylline-induced increase of intracellular calcium at clinically relevant concentrations. However, aminophylline reversed the inhibitory effect of propofol on the elevation of intracellular calcium by lysophosphatidic acid. Our results suggest that propofol and aminophylline antagonize each other on the mobilization of intracellular calcium in human umbilical vein endothelial cells at clinically relevant concentrations. Serious consideration should be given to how this interaction affects mobilization of intracellular calcium when these two drugs are used together.
Subject(s)
Humans , Aminophylline/antagonists & inhibitors , Anesthetics, Intravenous/antagonists & inhibitors , Bronchodilator Agents/antagonists & inhibitors , Calcium/metabolism , Cells, Cultured , Endothelial Cells/drug effects , Endothelium, Vascular/cytology , Lysophospholipids/pharmacology , Microscopy, Confocal , Propofol/antagonists & inhibitors , Umbilical Veins/cytologyABSTRACT
La aminofilina, un antagonista no específico de las benzodiazepinas, fue evaluada para determinar su acción en la reversión de la sedacción de pacientes sometidos a legrados uterinos o braquiterapia intrauterina bajo anestesia general. Veintiocho pacientes recibieron Fentanil 3ug.kg-1, Diazepán 0.2 mg.kg-1 y Tiopental 4mg.kg-1, y fueron ventiladas con Oxido Nitroso- Oxígeno (66/33 por ciento). Después del procedimiento quirúrgico, cada paciente recibió en forma randomizada y doble ciego, ®droga activa¼ (aminofilina 4 mg.kg-1n=14) o ®placebo¼ (solución Salina isotónica; n = 14). Ambos grupos fueron similares en sus variables demográficas y no se detectaron diferencias en las determinaciones de presión arterial, frecuencia cardíaca y frecuencia respiratoria después de la administración de aminofilina. La recuperación fue bien tolerada y significativamente más rápida en el grupo aminofilina (30.9 min+DS4.91) que en el grupo control (39.0 min. + DS 8.06) (p<0.01). Los niveles de sedación revirtieron antes que en el grupo control <0.05), pero esta deferencia desaparecio 30 minutos después de finalizado el procedimiento anestésico quirúrgico. Se infiere que en las pacientes que recibieron fentanil, diazepán y tiopental, la aminofilina acelera el despertar, probablemente debido al bloqueo de los receptores de adenosina
Subject(s)
Humans , Female , Aminophylline/administration & dosage , Aminophylline/antagonists & inhibitors , Aminophylline/therapeutic use , Diazepam/adverse effects , Diazepam/antagonists & inhibitors , Diazepam/therapeutic use , Fentanyl/therapeutic use , Thiopental/therapeutic useABSTRACT
Aminophylline, 285.7 +/- 2.19 mg/kg infused intravenously in unanaesthetized rats produced onset of seizures within 3.2 +/- 0.99 minutes. Seizures were repetitive and death occurred in 10.5 +/- 1.75 minutes. Pretreatment of rats with carbamazepine, sodium valproate and diazepam at doses that prevented electroshock induced seizures were effective in significantly postponing seizures and death, but did not reduce mortality. Concomitant EEG studies in aminophylline infused rats showed that cortical excitability evidenced by initial cortical spiking occurred at 42 secs and polyspiking at 165 seconds. Following diazepam, the initial cortical spike was delayed 50 fold, appearing after 36 minutes. Antiepileptic drugs and EEG monitoring may prove useful in patients with status asthmaticus receiving intravenous aminophylline.