The hypothalamic paraventricular nucleus and carotid receptors modulate hyperglycemia induced by hemorrhage

• DOI: 10.1016/j.brainres.2003.09.013
• Publication Date: 2003-10-24T17:43:31Z
• Authors: Simonton Andrade ...; Nilo Resende Vian...; Andréa Siqueira H...; Cândido Celso Coi...
• Keywords: Blood Glucose; Male; Carotid Body; Time Factors; Microinjections; Statistics as Topic; 05 social sciences; Blood Pressure; Hemorrhage; Sodium Chloride; Denervation; Models, Biological; Rats; Carotid Arteries; Heart Rate; Hyperglycemia; Animals; 0501 psychology and cognitive sciences; Atropine Derivatives; Rats, Wistar; Paraventricular Hypothalamic Nucleus

The aim of this study was to assess the role of cholinergic transmission in the paraventricular nucleus of the hypothalamus (PVN) and carotid body receptors in mediating a rise in plasma glucose levels in response to hemorrhagic hypotension in rats. Methylatropine (1x10(-9) mol) or 0.15 M NaCl (0.2 microl) was injected into the PVN of Wistar rats weighing 250-300 g bearing a chronic jugular catheter for blood sampling and hemorrhage (1.2 ml/100 g/2 min). Polyethylene cannulae (PE-10) were inserted into the left femoral artery for cardiovascular monitoring. In the other experimental protocol, hemorrhage was performed on rats submitted to bilateral carotid receptor denervation (H-CD). The results show that the hyperglycemic response to hemorrhage was decreased by either methylatropine (H-MA) treatment or bilateral carotid receptor denervation (10.3+/-0.4 mM, control, n=15 vs. 7.7+/-0.2 mM, H-MA, n=12, and 7.6+/-0.3 mM, H-CD, n=5, p<0.01). Furthermore, methylatropine did not affect the recovery of blood pressure after hemorrhage-induced hypotension, suggesting that the metabolic and pressor adjustments have different efferent pathways. Our data demonstrate that cholinergic input from the PVN and carotid receptors (chemo- and/or baroreceptors) might participate in the same neural pathway activated by hemorrhage-induced hypotension that produces hyperglycemia.