| First Author | Rinaman L | Year | 2005 |
| Journal | Am J Physiol Regul Integr Comp Physiol | Volume | 288 |
| Issue | 6 | Pages | R1791-9 |
| PubMed ID | 15718385 | Mgi Jnum | J:98510 |
| Mgi Id | MGI:3578595 | Doi | 10.1152/ajpregu.00860.2004 |
| Citation | Rinaman L, et al. (2005) Dehydration anorexia is attenuated in oxytocin-deficient mice. Am J Physiol Regul Integr Comp Physiol 288(6):R1791-9 |
| abstractText | Evidence in rats suggests that central oxytocin (OT) signaling pathways contribute to suppression of food intake during dehydration (i.e., dehydration anorexia). The present study examined water deprivation-induced dehydration anorexia in wild-type and OT -/- mice. Mice were deprived of food alone (fasted, euhydrated) or were deprived of both food and water (fasted, dehydrated) for 18 h overnight. Fasted wild-type mice consumed significantly less chow during a 60-min refeeding period when dehydrated compared with their intake when euhydrated. Conversely, fasting-induced food intake was slightly but not significantly suppressed by dehydration in OT -/- mice, evidence for attenuated dehydration anorexia. In a separate experiment, mice were deprived of water (but not food) overnight for 18 h; then they were anesthetized and perfused with fixative for immunocytochemical analysis of central Fos expression. Fos was elevated similarly in osmo- and volume-sensitive regions of the basal forebrain and hypothalamus in wild-type and OT -/- mice after water deprivation. OT-positive neurons expressed Fos in dehydrated wild-type mice, and vasopressin-positive neurons were activated to a similar extent in wild-type and OT -/- mice. Conversely, significantly fewer neurons within the hindbrain dorsal vagal complex were activated in OT -/- mice after water deprivation compared with activation in wild-type mice. These findings support the view that OT-containing projections from the hypothalamus to the hindbrain are necessary for the full expression of compensatory behavioral and physiological responses to dehydration. |
