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DOI: 10.1055/s-0038-1640256
The cannabinoid receptor 2 agonist JWH-133 is capable of revoking changes in cochlear microcirculation induced by lipopolysaccharide
Introduction:
Cannabinoid receptors (CBR) are divided into two subclasses. The subtype 2 mediates several antiinflammatory effects that make it a valid candidate as an otoprotective agent. We therefore investigated the ability of JWH-133, a CBR-2 agonist, to reduce the effects of abacterial labyrinthitis on cochlear microcirculation.
Material and Methods:
40 dunkin-hartley guines pigs were divided into 8 groups of 5 animals each. In each animal cochlear microcirculation was quantified by in-vivo fluorescence microscopy. In the first four groups, lipopolysaccharide (LPS) was applied topically in various concentration (1 mg/ml, 10 µg/ml, 100 ng/ml, placebo) to emulate the effects of abacterial labyrinthitis. In the second four groups, JWH-133 (500 ng/ml), a potent CBR-2 agonist, was applied topically before application of LPS. Microcirculation was quantified before, 30 minutes after the initial treatment and at the end of the second treatment.
Results:
30 and 60 minutes after topical application of LPS, microcirculation dropped to 79.1% or 75.6%, respectively (1 mg/ml), to 88.8% or 81.7%, respectively (10 µg/ml) and to 96.8% or 89.3%, respectively (100 ng/ml). Application of Placebo caused no such decreases in microcirculation (99.8% and 99.6% from the basal values). Previous application of JWH-133 showed no changes in microcirculation (97.8% of the basal values). The subsequent application of LPS then caused no changes in microcirculation (99.0% of the basal values).
Conclusion:
JWH-133 is capable of abrogating the effects of abacterial labyrinthitis on cochlear microcirculation. It therefore is a valid candidate as an otoprotective agent in bacterial otitis media and various other inner ear pathologies.
No conflict of interest has been declared by the author(s).
Publikationsverlauf
Publikationsdatum:
18. April 2018 (online)
© 2018. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).
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