The effect of pentobarbital and ether anesthesia on rat brain PGD2 content

Effects of pentobarbital and ether anesthesia on PGD2 contents in brain and plasma levels of compound beta, A.C.TH. epinephrine (E) norepinephrine (NE) and dopamine were investigated in 39 male Wistar strain rats weighing 280-300 g. They were divided into 3 groups: pentobarbital anesthesia group (P.A.), ether anesthesia group (E.A.) and control. Anesthesia or not the rats were decapitated the heads were frozen with liquid nitrogen and PGD2 were extracted and assayed by radioimmunoassay. In the group of P.A. and E.A., PGD2 contents of the brain were decreased by 69.6% and 77.8% of the control group respectively. In the group PA, plasma levels of Comp-beta, ACTH, E and NE were significantly decreased. In the EA group, plasma levels of Comp-beta was not changed but that of ACTH, E and NE were significantly increased. In the EA and PA groups, plasma levels of dopamine were not significantly changed. Intraventricularly injected PGD2 has been reported to induce the natural sleep in rat, increase or decrease the pain threshold and lower the body temperature in rat. On the other hand, intravenous injection of PGD2 has been reported to prolong the duration of pentobarbital anesthesia in rat or changed the EEG pattern to slow wave in cat. Stresses including restrain and foot shock have been reported to increase the PGE2 and PGF2a in the brain of rat. The present findings demonstrate that pentobarbital and ether anesthesia decreased the PGD2 contents in the brain of rat.