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An Association Between Ethanol‐Evoked Enhancement of c‐ jun Gene Expression in the Nucleus Tractus Solitarius and the Attenuation of Baroreflexes
Author(s) -
Wang Xu,
AbdelRahman Abdel A.
Publication year - 2004
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1097/01.alc.0000137299.04112.c2
Subject(s) - baroreflex , baroreceptor , endocrinology , solitary nucleus , medicine , immediate early gene , c fos , in situ hybridization , c jun , messenger rna , gene expression , premovement neuronal activity , chemistry , stimulation , heart rate , blood pressure , biology , neuroscience , gene , transcription factor , biochemistry
Background: An increased expression of Fos, the protein product of the immediate early gene c‐ fos , in the nucleus tractus solitarius (NTS) is associated with dysfunction in baroreceptor reflex control of heart rate. Our previous studies demonstrated that ethanol attenuates baroreflex sensitivity (BRS) in rats and humans. In this study, we tested the hypothesis that enhanced expression of the immediate early gene c‐ jun (an index of neuronal activity) in the NTS contributes to the baroreflex dysfunction caused by ethanol. Methods: Conscious male spontaneously hypertensive (SHR) and Wistar‐Kyoto (WKY) rats were used to measure blood pressure, heart rate, and baroreflex sensitivity (Oxford method). The c‐ jun messenger RNA (mRNA) expression in NTS was measured by in situ hybridization. Results: Ethanol elicited dose‐dependent attenuation in BRS in WKY rats, which was associated with significant increases in c‐ jun mRNA in the NTS. In contrast, ethanol had no effect on BRS or c‐ jun mRNA in the NTS of the SHRs; the latter exhibited significantly lower BRS and higher c‐ jun mRNA in the NTS compared with WKY rats. Conclusions: An increased basal level of c‐ jun mRNA in the NTS may contribute to the reduced BRS in the SHR, and ethanol enhancement of neuronal activity of the NTS, expressed as increased c‐ jun mRNA expression, may contribute to its attenuation of BRS, which highlights the NTS as a neuroanatomical target for ethanol action on baroreflexes.