Selective effects of pentobarbital and halothane on c-fos and jun-B gene expression in rat brain

The effects of pentobarbital and halothane anesthesia on the expression in brain of the immediate-early genes c-fos and jun-B were investigated. Pentobarbital-anesthetized rats (n = 10) received a single intraperitoneal injection of pentobarbital 65 mg/kg in a vehicle of 40% propylene glycol and 10% ethanol and then were placed in a plexiglass box flushed continously with 100% oxygen at 5 l/min. Halothane-anesthetized rats (n = 10) received an intraperitoneal injection of vehicle only and were transferred to a box flushed continuously with oxygen plus 1.5% halothane. Unanesthetized control rats (n = 10) received an intraperitoneal injection of vehicle and were placed in a box flushed continuously with 100% oxygen. Four additional rats received no intraperitoneal injection but were handled and otherwise treated identically to the control group, and six others had a femoral arterial catheter inserted for blood pressure and blood gas measurements. Five animals from the control and both anesthetized groups were killed at 30 and 120 min postinjection and their brains rapidly removed and frozen. The messenger ribonucleic acid transcription products of the genes c-fos, jun-B, and beta-actin from whole cerebral hemispheres were analyzed autoradiographically after Northern blot hybridization with 32P-labeled deoxyribonucleic acid probes. Relative levels of c-fos and jun-B messenger ribonucleic acid were determined from optical density measurements of the autoradiographic bands, with beta-actin measurements being used to correct for sample-to-sample variation. Rats became immobile within minutes of drug administration and remained anesthetized until they were killed.(ABSTRACT TRUNCATED AT 250 WORDS)