| First Author | Morris M | Year | 2001 |
| Journal | Am J Physiol Regul Integr Comp Physiol | Volume | 280 |
| Issue | 4 | Pages | R1177-84 |
| PubMed ID | 11247842 | Mgi Jnum | J:68658 |
| Mgi Id | MGI:1933032 | Doi | 10.1152/ajpregu.2001.280.4.R1177 |
| Citation | Morris M, et al. (2001) Enhanced central response to dehydration in mice lacking angiotensin AT(1a) receptors. Am J Physiol Regul Integr Comp Physiol 280(4):R1177-84 |
| abstractText | The objective was to determine the central nervous system (CNS) responses to dehydration (c-Fos and vasopressin mRNA) in mice lacking the ANG AT(1a) receptor [ANG AT(1a) knockout (KO)]. Control and AT(1a) KO mice were dehydrated for 24 or 48 h. Baseline plasma vasopressin (VP) was not different between the groups; however, the response to dehydration was attenuated in AT(1a) KO (24 +/- 11 vs. 10.6 +/- 2.7 pg/ml). Dehydration produced similar increases in plasma osmolality and depletion of posterior pituitary VP content. Neuronal activation was observed as increases in c-Fos protein and VP mRNA. The supraoptic responses were not different between groups. In the paraventricular nucleus (PVN), c-Fos-positive neurons (57.4 +/- 10.7 vs. 98.4 +/- 7.4 c-Fos cells/PVN, control vs. AT(1a) KO) and VP mRNA levels (1.0 +/- 0.1 vs. 1.4 +/- 0.1 microCi, control vs. AT(1a) KO) were increased with greater responses in AT(1a) KO. A comparison of 1- to 2-day water deprivation showed that plasma VP, brain c-Fos, and VP mRNA returned toward control on day 2, although plasma osmolality remained high. Data demonstrate that AT(1a) KO mice show a dichotomous response to dehydration, reduced for plasma VP and enhanced for PVN c-Fos protein and VP mRNA. The results illustrate the importance of ANG AT(1a) receptors in the regulation of osmotic and endocrine balance. |
