Adrenergic control of glycemia in the paraventricular nucleus of the hypothalamus in pigeons.
The effects of local injections of adrenaline into the paraventricular nucleus (PVN) and into other anterior hypothalamic areas on blood glucose levels were investigated in conscious pigeons (Columba livia). Adrenaline evoked a reliable and potent increase in blood glucose levels when injected into the PVN; no glycemic change was observed after vehicle injections into the PVN or after adrenaline injections into the 3rd ventricle or hypothalamic structures adjacent to the PVN. Local pretreatment with propranolol, but not with phentolamine, abolished the adrenaline-induced hyperglycemia. The present results indicate that adrenergically mediated circuits into the avian PVN play an important role in central mechanisms of energy balance that may be equivalent to those observed in mammalian species.
Sabi
Marcelo
M
Department of Physiological Sciences CCB, Federal University of Santa Catarina, 88040-900 Florianópolis, SC, Brazil.
Raimondi
Cesar
C
Marques
Sandro
S
Paschoalini
Marta Aparecida
MA
Marino-Neto
José
J
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D010856:Columbidae / Q000033:anatomy & histology / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology*; D004837:Epinephrine / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D009434:Neural Pathways / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D004837:Epinephrine