This study investigated the role that sensory nerves play in mediating the hormone and glucose metabolic response to endotoxin [lipopolysaccharide (LPS)]. Adult rats were pretreated subcutaneously with capsaicin to selectively destroy primary sensory afferent nerve fibers. Ten days later, [3-3H]glucose was infused intravenously to assess whole body glucose flux before and after the intravenous injection of Escherichia coli LPS (100 μg/100 g body wt). Control animals responded to LPS with characteristic increases in the plasma concentration of glucose (91%) and lecture (threefold) and elevations in the rates of glucose appearance and disappearance (77%). In capsaicin-treated rats, the maximal LPS-induced increase in these parameters was attenuated by 50-60%. In addition, these animals were hypoglycemic at the conclusion of the experiment. Control animals demonstrated early and sustained elevations in circulating levels of corticosterone, glucagon, and catecholamines. In contrast, the early LPS- induced elevation in epinephrine and norepinephrine, and to a lesser extent glucagon, was completely absent or greatly impaired by capsaicin pretreatment. In a separate study, the epinephrine-induced increase in glucose flux was blunted by 75% in capsaicin-treated rats. These data indicate that sensory afferent neurons play a critical role in the early secretory response of glucagon and catecholamines, the maintenance of tissue catecholamine responsiveness, and the stimulation of glucose production after LPS.
|Original language||English (US)|
|Journal||American Journal of Physiology - Endocrinology and Metabolism|
|Issue number||2 36-2|
|State||Published - 1997|
All Science Journal Classification (ASJC) codes
- Endocrinology, Diabetes and Metabolism
- Physiology (medical)