Anesthesia and anesthetic action mechanism of essential oils of Aloysia triphylla and Cymbopogon flexuosus in silver catfish (Rhamdia quelen)

作者：dos Santos Alessandro C; Junior Guerino B; Zago Daniane C; Zeppenfeld Carla C; da Silva Daniela T; Heinzmann Berta M; Baldisserotto Bernardo; da Cunha Mauro A^*

来源：Veterinary Anaesthesia and Analgesia, 2017, 44(1): 106-113.

DOI：10.1111/vaa.12386

• diazepam
• fish
• flumazenil
• gamma-aminobutyric acid
• sedation

Objectives To document the time for anesthesia induction and recovery using different concentrations of essential oils (EOs) of Cymbopogon flexuosus and Aloysia triphylla in silver catfish (Rhamdia quelen), and to determine whether the mechanism of action of either EO involves the benzodiazepine (BDZ) site of the GABA(A) receptor.
Study design Experimental study.
Animals A total of 144 silver catfish, length 7.5 +/- 1.1 cm, weighing 3.95 +/- 0.85 g.
Methods Essential oils were evaluated at concentrations of 25, 150 and 300 mL L-1, and also ethanol alone (seven groups, n = 6 per group). Induction of sedation or anesthesia and recovery were assessed. In a further six groups (n = 6 per group), fish were exposed to both EOs (25, 150 or 300 mL L-1) with diazepam 150 mM, and also diazepam (10 mM) alone. Flumazenil (5 or 10 mM) was added to the recovery water of fish exposed to diazepam (150 mM) or both EOs (150 and 300 mL L-1) (total of 10 groups = 60 fish).
Results Both EOs induced anesthesia at concentrations of 150 and 300 mL L-1, and sedation at 25 mL L-1. There was no significant difference between EOs for reaching deep anesthesia; there was a significantly longer recovery time for the EO of C. flexuosus. The addition of diazepam (150 mM) resulted in faster induction of anesthesia with both EOs, with no significant change in recovery times. Flumazenil (10 mM) reversed the diazepam-induced anesthesia, but not the anesthesia induced by EOs.
Conclusions and clinical relevance The EO of C. flexuosus induced effective sedation (25 mL L-1) and anesthesia (150 and 300 mL L-1) without short-term mortality. The modulation of the BDZ site of the GABA(A) receptor in the anesthetic action mechanism of both EOs was not demonstrated.

• 出版日期2017-1