Octreotide-induced suppression of the hyperglycemic response to neostigmine or bombesin: relationship to hypothalamic noradrenergic drive

Neostigmine (cholinesterase inhibitor) or bombesin, when injected into the third cerebral ventricle of awake rat, dose-dependently increased ser-um gl ucose with the simultaneous rise in hypothalamic noradrenergic neuronal act ivity (NAA). Co-administration of octreotide with neostigmine or bombesin s uppressed the hypothalamic NNA response with the simultaneous inhibition of the hyperglycemic response. There was a close relationship between hypotha lamic NNA and serum glucose in these studies. On the basis of the concept t hat hypothalamic noradrenergic drive plays an important role in mediating t he hyperglycemic response to stressful stimuli, the present findings sugges t that the hyperglycemic response to neostigmine or bombesin is mediated vi a the interaction with hypothalamic noradrenergic neurons. (C) 2001 Elsevie r Science B.V. All rights reserved.