Effect of transection of various branches of the vagus nerve on lipopolysaccharide-induced synthesis of corticotropin-releasing hormone mRNA in the paraventricular nuclei of rat hypothalamus.
Effects of selective transection of the gastric, celiac, and hepatic branches of the vagus nerve on expression of corticotropin-releasing hormone mRNA in small cell neurons of the hypothalamic paraventricular nuclei in rats administered with bacterial lipopolysaccharide were studied using in situ hybridization technique. Low doses of lipopolysaccharide stimulated expression of corticotropin-releasing hormone mRNA in rats subjected to axotomy of the gastric or celiac branches of the vagus nerve, but did not change the intensity of autoradiographic labeling in animals with transected hepatic branches. High doses of lipopolysaccharide enhanced expression of corticotropin-releasing hormone mRNA in vagotomized rats of all groups, which indicated the existence of a vagus-independent mechanism responsible for activation of paraventricular neurons mediating the effect of this hormone. The data suggest that the inflammation-dependent activation of stress-regulating neurons in the hypothalamus is controlled by several mechanisms, whose activation depends on the severity of inflammatory processes.
Sergeev
V G
VG
Institute of Experimental Endocrinology, Endocrinology Research Center, Russian Academy of Medical Sciences, Moscow.
Akmaev
I G
IG
D000818:Animals; D001345:Autoradiography; D003346:Corticotropin-Releasing Hormone / Q000096:biosynthesis / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014630:Vagus Nerve / Q000601:surgery*
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D003346:Corticotropin-Releasing Hormone