caa a22 4500 465738605 CHVBK 20180323111802.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF02245792 doi (NATIONALLICENCE)springer-10.1007/BF02245792 Effects of a selective mu opioid receptor agonist and naloxone on the intake of sodium chloride solutions [Elektronische Daten] [Blake Gosnell, Mark Majchrzak] Endogenous opioid peptides are thought to play a role in mediating the palatability or rewarding aspects of sweet tastes. There is also evidence, however, which suggests that opioids may influence the preference for the taste of salt as well. In the present studies, we measured the effects of central administration of naloxone and the mu agonist [d-Ala2,MePhe4,Gly-ol5]enkephalin (DAGO) on the ingestion of salt solutions. In non-deprived rats given a choice of water and 0.6% saline, ICV injections of DAGO (1 and 3 nmol) significantly increased the intake of 0.6% saline; baseline water intake was minimal and was unaffected by DAGO. When rats were given a choice between water and 1.7% saline, DAGO stimulated both water and saline intake. Because 1.7% saline is a hypertonic solution, the increase in water intake may have been secondary to saline intake. In rats on a deprivation schedule in which water and 0.6% saline were available for only 2-3 h/day, there was a tendency for DAGO to increase 0.6% saline intake and decrease water intake, though these effects were not significant. In rats given water and 1.7% saline, DAGO increased saline intake and had no effect on water intake. Naloxone was also tested in water-deprived rats. Naloxone (20 and 50 µg) significantly decreased 0.6% saline intake; baseline water intake was low (3-5 ml) and was unaffected by naloxone. When rats were given a choice between water and 1.7% saline, naloxone (50 µg) significantly reduced water intake, while intake of 1.7% saline was slightly increased. These results suggest a role for central mu opioid receptors in mediating the preference for salt solutions. Springer-Verlag, 1990 Opioids nationallicence Saline intake nationallicence Naloxone nationallicence Reward nationallicence Palatability nationallicence Taste preference nationallicence Drinking nationallicence Gosnell Blake Department of Psychiatry, University Hospital, 8D8806, University of Michigan, Box 0116, 48109-0116, Ann Arbor, MI, USA aut Majchrzak Mark Department of Psychiatry, University Hospital, 8D8806, University of Michigan, Box 0116, 48109-0116, Ann Arbor, MI, USA aut Psychopharmacology Springer-Verlag 100/1(1990-03-01), 66-71 0033-3158 100:1<66 1990 100 213 https://doi.org/10.1007/BF02245792 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02245792 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gosnell Blake Department of Psychiatry, University Hospital, 8D8806, University of Michigan, Box 0116, 48109-0116, Ann Arbor, MI, USA aut NATIONALLICENCE 700 1- Majchrzak Mark Department of Psychiatry, University Hospital, 8D8806, University of Michigan, Box 0116, 48109-0116, Ann Arbor, MI, USA aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 100/1(1990-03-01), 66-71 0033-3158 100:1<66 1990 100 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer