Effect Of Eugenol On The NO-cGMP Signal Pathway In CNS Of Cyprinus Carpio

Highly demanding were emerged during anesthesia process because of the fish physiology feature. The efficient way to meet this problem must develope a new type anesthesia agent, which owns good performance, long anesthesia time, recovery quick.This drug residues in fish was less and it is cheap and safety for people and fish. In the study, the anesthesia molecule mechanism of Eugenol to Cyprinus Carpio was investigated through determining effect on the activity change of two sort ATPases and NOS, the content of NO, cAMP and cGMP in brains of Cyprinus Carpio, which narcotized by Eugenol. The research result might provide useful reference for anesthesiology and developing efficient safe anesthesia to fish.1、36 cyprinoid fishes, each weight between 900 g~1000 g as the experimental animals,were divided into 6 groups randomly and each group had 6 fishes. The optimal anesthetic concentration of eugenol emulsion was investigated in one of six different concentrations(20,30,40,60,80 mg/L and 120 mg/L) between 20~22℃ of water temperature, and repeated the process for 5 times. The results showed that the time to reach anaesthesia period was negatively correlated with concentration, and the recovery time was positively correlated with concentration. The cyprinoid’s optimal anesthetic concentration of eugenol emulsion was 40 mg/L when cyprinoid fish was900 g~1000 g.2、160 cyprinoid fishes as the experimental animals were divided into 4 groups randomly. 40 fishes were in the control group and the other 120 fishes were in eugenol emulsion which concentration was 40 mg/L. Then the brain and the spinal cord tissues were taken during induction period, or anesthesia period or recovery period respectively. The activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase were detected by spectrophotometry. Results: After anaesthetized by eugenol emulsions,the activities of both ATPases which were in the brain and the spinal cord tissues of Cyprinus carpio were inhibited in different degrees during the anaesthetic periods.And the inhibitory effects were enhanced when the anesthesia was deepening. And the strongest inhibitory effect was in anesthetic period. Compared with control group, the Na+-K+-ATPase activities of the fish brain and the spinal cord tissues in anesthesia period were significantly decreased(P<0.01). Ca2+-Mg2+-ATPase activities in the cerebrum, mesencephalon, cerebellum, diencephalon and spinal cord were significantly decreased(P<0.01). Ca2+-Mg2+-ATPase activities in the medulla oblongata were decreased(P<0.05). Compared with anaesthetic period, both of these enzymes activities in the cerebrum, mesencephalon, cerebellum and spinal cord raised significantly in recovery period(P<0.01). Both of these enzymes activities were all lower than control group. They were closely related to anesthesia depth.Conclusion: Eugenol inhibited the ATPase activities in brain and the spinal cord tissues significantly of Cyprinus carpio Linnaeus in anesthesia periods. It suggested that the Eugenol anaesthetic mechanism to Cyprinus carpio Linnaeus may work through inhibiting the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in the fish brainsand the spinal cord.3 、 With the same experiment process and same method to collect and treat samples, the cAMP concentration in the brains and the spinal cord of Cyprinus carpio Linnaeus determined by ELISA within different anaesthetic periods. Results: After anaesthetized with eugenol emulsions, the cAMP concentrations in the cerebrum,mesencephalon, diencephalon, medulla oblongata and spinal cord were increased along with the deepening of anesthesia. Compared with control group, the cAMP concentrations in brains and spinal cord in anesthesia period were significantly raised(P<0.01). And the concentration was maximum in anesthesia. Compared with anaesthetic period, the cAMP concentrations in the cerebrum, mesencephalon,diencephalon and medulla oblongata decreased significantly in recovery period(P<0.01). The cAMP concentrations in diencephalon were even below significantly the level of control group(P<0.01). Then the cAMP concentrations in the cerebrum,mesencephalon, medulla oblongata and spinal cord were still much higher than the control group(P<0.01). The results showed that the cAMP in the cerebrum,mesencephalon, diencephalon, medulla oblongata and spinal cord of Cyprinus carpioLinnaeus might participate in the regulation process during eugenol anesthesia.4 、 With the same experiment process and same method to collect and treat samples, the cGMP concentration in the brains and the spinal cord of Cyprinus carpio Linnaeus determined by ELISA within different anaesthetic periods. Results: After anaesthetized with eugenol emulsions, the cGMP concentrations in the cerebrum,mesencephalon, diencephalon, medulla oblongata and spinal cord were inhibited along with the deepening of anesthesia. Compared with control group, the cGMP concentrations in the cerebellum, diencephalon and spinal cord in anesthesia period were significantly decreased(P<0.01), the cGMP concentrations in cerebrum,mesencephalon and medulla oblongata were decreased(P<0.05). The cGMP concentrations in the brains raised in recovery period, and the cGMP concentrations in cerebellum and spinal cord were significantly higher than it in anesthesia period(P<0.01), and which in spinal cord was almost raised near to the level of control group. The cGMP concentrations in other brains was all lower than control group.5 、 With the same experiment process and same method to collect and treat samples, the NO content, NOS and iNOS activities in the brains were determined by spectrophotometry. Results: The NO content in the cyprinoid cerebrum,mesencephalon, cerebellum, diencephalon and spinal cord in anesthesia period were decreased(P<0.05). The NOS and iNOS activities were inhibitied(P<0.05). The mechanism of narcotizing Cyprinus carpio Linnaeus was related to inhibite NO metabolism in the cerebrum, mesencephalon, cerebellum, diencephalon and spinal cord.