Enhanced central response to dehydration in mice lacking angiotensin AT1areceptors
| Autor: | Thomas M. Coffman, Mariana Morris, Michael I. Oliverio, Shelia Means |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Vasopressin Genotype Transcription Genetic Vasopressins Physiology Central nervous system Neuropeptide Biology Receptor Angiotensin Type 1 Mice Physiology (medical) Internal medicine Renin–angiotensin system medicine Animals RNA Messenger Receptor Crosses Genetic In Situ Hybridization Mice Knockout Neurons Receptors Angiotensin Angiotensin II receptor type 1 Dehydration Genes fos Immunohistochemistry Angiotensin II Endocrinology medicine.anatomical_structure Gene Expression Regulation Hypothalamus Pituitary Gland Female |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 280:R1177-R1184 |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.2001.280.4.r1177 |
| Popis: | The objective was to determine the central nervous system (CNS) responses to dehydration (c-Fos and vasopressin mRNA) in mice lacking the ANG AT1areceptor [ANG AT1aknockout (KO)]. Control and AT1aKO 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 AT1aKO (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. AT1aKO) and VP mRNA levels (1.0 ± 0.1 vs. 1.4 ± 0.1 μCi, control vs. AT1aKO) were increased with greater responses in AT1aKO. 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 AT1aKO 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 AT1areceptors in the regulation of osmotic and endocrine balance. |
| Databáze: | OpenAIRE |
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