Carbenoxolone does not Improve Sevoflurane-induced Neurotoxicity in the Developing Rat Hippocampus
Background: Connexin 43 is the most abundant connexin protein expressed in astrocytes. Our previous research found that sevoflurane-induced neurotoxicity was related to Cx43 via JNK/MAPK/Ap-1 signaling pathway. Cx43 functions through hemichannels (HCs) and gap junctions (GJs) and both of them could affect the homeostasis of central nervous system. Carbenoxolone (Cbx) is generally considered as a Cx43 hemichannel and gap junction inhibitor in traditional applications. Therefore, we hypothesized that preadministration of Cbx may attenuate sevoflurane-induced cognitive dysfunction.
Methods: Seven-day-old SD rats (P7) were exposed to 3% sevoflurane for 4 hours with or without Cbx pretreatment at a dose of 50 mg/kg. Levels of Bcl-2, Bax, Cx43 and caspase-3 positive cells in P8 rat’s hippocampus were examined using Western blotting and immunohistochemistry. Morris water maze was performed from P28 to P33 to test the cognitive function.
Results: Cx43 levels and caspase-3 positive cells in P7 rat hippocampus were increased 1 day after exposure to 3% sevoflurane for 4 h compared with control rats. Sevoflurane anesthesia decreased the expression of Bcl-2 and increased the expression of Bax in P8 rat’s hippocampus (P<0.05, n=5). Exposure to sevoflurane led to significant cognitive impairment from P28 to P33.All these defects could not be alleviated by pretreatment with Cbx.
Conclusions: These data suggested that Cbx could not improve sevoflurane-induced neurotoxicity by inhibiting Cx43 HCs in the developing brain.
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Posted 21 Jan, 2021
Received 28 Feb, 2021
On 26 Feb, 2021
On 26 Feb, 2021
Invitations sent on 25 Feb, 2021
On 25 Feb, 2021
On 19 Jan, 2021
On 19 Jan, 2021
On 15 Jan, 2021
Carbenoxolone does not Improve Sevoflurane-induced Neurotoxicity in the Developing Rat Hippocampus
Posted 21 Jan, 2021
Received 28 Feb, 2021
On 26 Feb, 2021
On 26 Feb, 2021
Invitations sent on 25 Feb, 2021
On 25 Feb, 2021
On 19 Jan, 2021
On 19 Jan, 2021
On 15 Jan, 2021
Background: Connexin 43 is the most abundant connexin protein expressed in astrocytes. Our previous research found that sevoflurane-induced neurotoxicity was related to Cx43 via JNK/MAPK/Ap-1 signaling pathway. Cx43 functions through hemichannels (HCs) and gap junctions (GJs) and both of them could affect the homeostasis of central nervous system. Carbenoxolone (Cbx) is generally considered as a Cx43 hemichannel and gap junction inhibitor in traditional applications. Therefore, we hypothesized that preadministration of Cbx may attenuate sevoflurane-induced cognitive dysfunction.
Methods: Seven-day-old SD rats (P7) were exposed to 3% sevoflurane for 4 hours with or without Cbx pretreatment at a dose of 50 mg/kg. Levels of Bcl-2, Bax, Cx43 and caspase-3 positive cells in P8 rat’s hippocampus were examined using Western blotting and immunohistochemistry. Morris water maze was performed from P28 to P33 to test the cognitive function.
Results: Cx43 levels and caspase-3 positive cells in P7 rat hippocampus were increased 1 day after exposure to 3% sevoflurane for 4 h compared with control rats. Sevoflurane anesthesia decreased the expression of Bcl-2 and increased the expression of Bax in P8 rat’s hippocampus (P<0.05, n=5). Exposure to sevoflurane led to significant cognitive impairment from P28 to P33.All these defects could not be alleviated by pretreatment with Cbx.
Conclusions: These data suggested that Cbx could not improve sevoflurane-induced neurotoxicity by inhibiting Cx43 HCs in the developing brain.
Figure 1
Figure 2
Figure 3
Figure 4