Peripheral administration of CDP-choline and its cholinergic metabolites increases serum insulin: Muscarinic and nicotinic acetylcholine receptors are both involved in their actions
NEUROSCIENCE LETTERS, cilt.431, sa.1, ss.71-76, 2008 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 431 Sayı: 1
- Basım Tarihi: 2008
- Doi Numarası: 10.1016/j.neulet.2007.11.024
- Dergi Adı: NEUROSCIENCE LETTERS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.71-76
- Anahtar Kelimeler: CDP-choline, choline, insulin, glucose, cholinergic, RELEASE, GLUCOSE, RAT, SECRETION, CYTIDINE, CNS
- Bursa Uludağ Üniversitesi Adresli: Evet
Özet
The present study was designed to test the effects of CDP-choline and its metabolites on serum insulin concentrations in rats and to investigate the involvements of cholinergic and adrenergic receptors in the effect. Intraperitoneal (i.p.) administration of CDP-choline (200-600 mu mol/kg) increased serum insulin in a dose- and time-related manner. Equivalent doses (200-600 mu mol/kg; i.p.) of phosphocholine or choline also increased serum insulin dose-dependently. Serum-free choline concentrations increased several-fold following i.p. administration of CDP-choline, phosphocholine or choline itself. In contrast, equivalent doses of cytidine monophosphate and cytidine failed to alter serum insulin concentrations. The increases in serum insulin induced by i.p. 600 mu mol/kg of CDP-choline, phosphocholine or choline were abolished by pretreatment with the ganglionic nicotinic acetylcholine receptor antagonist hexamethonium (15 mg/kg; i.p.), or by the muscarinic receptor antagonist atropine methylnitrate (2 mg/kg; i.p.). Pretreatment with prazosin (0.5 mg/kg; i.p.), an alpha(1)-adrenoceptor antagonist, or yohimbine (5 mg/kg, i.p.), an alpha(2)-adrenoceptor antagonist, enhanced slightly the increases in serum insulin in response to 600 mu mol/kg of CDP-choline, phosphocholine and choline. Serum insulin also increased following central administration of choline; the effect was blocked by intracerebroventricularly injected atropine, mecamylamine or hemicholinium-3 (HC-3). It is concluded that CDP-choline or its cholinergic metabolites phosphocholine and choline increases circulating insulin concentrations by increasing muscarinic and nicotinic cholinergic neurotransmission in the insulin secreting beta-cells. (C) 2007 Elsevier Ireland Ltd. All rights reserved.