| Full text | |
| Author(s): |
Andrade, C. A. F.
[1]
;
Margatho, L. O.
[2]
;
Andrade-Franze, G. M. F.
[1]
;
De Luca, Jr., L. A.
[1]
;
Antunes-Rodrigues, J.
[2]
;
Menani, J. V.
[1]
Total Authors: 6
|
| Affiliation: | [1] Sao Paulo State Univ, UNESP, Sch Dent, Dept Physiol & Pathol, BR-14801903 Araraquara, SP - Brazil
[2] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Neuroscience; v. 208, p. 69-78, APR 19 2012. |
| Web of Science Citations: | 9 |
| Abstract | |
The deactivation of the inhibitory mechanisms with injections of moxonidine (alpha(2)-adrenoceptor/imidazoline receptor agonist) into the lateral parabrachial nucleus (LPBN) increases hypertonic NaCl intake by intra- or extracellular dehydrated rats. In the present study, we investigated the changes in the urinary sodium and volume, sodium balance, and plasma vasopressin and oxytocin in rats treated with intragastric (i.g.) 2 M NaCl load (2 ml/rat) combined with injections of moxonidine into the LPBN. Male Holtzman rats (n=5-12/group) with stainless steel cannulas implanted bilaterally into LPBN were used. Bilateral injections of moxonidine (0.5 nmol/0.2 mu l) into the LPBN decreased i.g. 2 M NaCIinduced diuresis (4.6 +/- 0.7 vs. vehicle: 7.4 +/- 0.6 ml/120 min) and natriuresis (1.65 +/- 0.29 vs. vehicle: 2.53 +/- 0.17 mEq/120 min), whereas the previous injection of the alpha(2)-adrenoceptor antagonist RX 821002 (10 nmol/0.2 mu l) into the LPBN abolished the effects of moxonidline. Moxonidine injected into the LPBN reduced i.g. 2 M NaCl-induced increase in plasma oxytocin and vasopressin (14.6 +/- 2.8 and 2.2 +/- 0.3 vs. vehicle: 25.7 +/- 7 and 4.3 +/- 0.7 pg/ml, respectively). Moxonidine injected into the LPBN combined with i.g. 2 M NaCl also increased 0.3 M NaCl intake (7.5 +/- 1.7 vs. vehicle: 0.5 +/- 0.2 mEq/2 h) and produced positive sodium balance (2.3 +/- 1.4 vs. vehicle: -1.2 +/- 0.4 mEq/2 h) in rats that had access to water and NaCl. The present results show that LPBN alpha(2)-adrenoceptor activation reduces renal and hormonal responses to intracellular dehydration and increases sodium and water intake, which facilitates sodium retention and body fluid volume expansion. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved. (AU) | |
| FAPESP's process: | 07/52343-8 - Interactions between serotoninergic, alpha2-adrenergic, gabaergic and opioidergic mechanisms of the lateral parabrachial nucleus in the control of nacl intake. |
| Grantee: | Carina Aparecida Fabrício de Andrade |
| Support Opportunities: | Research Grants - Meeting - Abroad |