title: Involvement of hypothalamic neuropeptide Y in pentazocine induced suppression of food intake in rats.
abstract: The potent orexigenic peptide neuropeptide Y (NPY) has been considered as a possible endogenous ligand for a subpopulation of sigma receptors (SigR). However, their mutual interaction with reference to feeding behavior remains poorly understood. In the present study, we explored the possible interaction between sigma1 receptors (Sig1R) agonist, pentazocine, and NPY on food intake in satiated rats. While pentazocine dose-dependently reduced the food intake, NPY significantly increased it at 2, 4 and 6h post injection time points. In combination studies, pretreatment with NPY (0.1 nmol/rat, intra-PVN) normalized the inhibitory effect of pentazocine (60 μg/rat, intra-PVN) on food intake. Similarly, pre-treatment with pentazocine (30 μg/rat, intra-PVN) significantly antagonized the orexigenic effect of NPY (0.5 and 1.0 nmol/rat, intra-PVN). Moreover, pentazocine treatment decreased NPY immunoreactivity in arcuate (ARC), paraventricular (PVN), dorsomedial (DMH) and ventromedial (VMH) nuclei of hypothalamus. However, no change was observed in lateral hypothalamus (LH). Study implicates the reduced NPY immunoreactivity for the anorectic effect observed following pentazocine injections. Therefore, the concomitant activation of the NPYergic system along with the Sig1R agonist treatment may serve a useful purpose in the management of the unwanted side effects related to energy homeostasis.
authors.affiliation: Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India.
authors.forename: Nandkishor R
authors.initials: NR
authors.lastname: Kotagale
authors.affiliation: Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India; Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University Campus, Nagpur 440 033, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Upadhya
authors.affiliation: Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India.
authors.forename: Pravin N
authors.initials: PN
authors.lastname: Hadole
authors.affiliation: Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University Campus, Nagpur 440 033, India.
authors.forename: Dadasaheb M
authors.initials: DM
authors.lastname: Kokare
authors.affiliation: Division of Neuroscience, Department of Pharmacology, Shrimati Kishoritai Bhoyar College of Pharmacy, New Kamptee, Nagpur 441 002, MS, India. Electronic address: nandukotagale@gmail.com.
authors.forename: Brijesh G
authors.initials: BG
authors.lastname: Taksande
mesh_terms: D000818:Animals; D001069:Appetite Regulation / Q000187:drug effects*; D004435:Eating / Q000187:drug effects*; D007031:Hypothalamus / Q000187:drug effects*; D008297:Male; D009478:Neuropeptide Y / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D010423:Pentazocine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017480:Receptors, sigma / Q000819:agonists*; D000097605:Sigma-1 Receptor
chemical_list: D009478:Neuropeptide Y; D018377:Neurotransmitter Agents; D010423:Pentazocine; D017480:Receptors, sigma; D000097605:Sigma-1 Receptor
keywords: Food intake; Hypothalamus; Immunohistochemistry; Neuropeptide Y; Pentazocine