Central nitric oxide blocks vasopressin, oxytocin and atrial natriuretic peptide release and antidiuretic and natriuretic responses induced by central angiotensin II in conscious rats
| Autor: | Lisandra Oliveira Margatho, Wagner Luis Reis, Renato Rizo Ventura, Alexandre Giusti-Paiva, Lucila Leico Kagohara Elias, José Antunes-Rodrigues, Dayane Aparecida Gomes |
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| Rok vydání: | 2007 |
| Předmět: |
Vasopressin
medicine.medical_specialty Chemistry General Medicine Angiotensin II Nitric oxide Natriuresis chemistry.chemical_compound Endocrinology medicine.anatomical_structure Oxytocin Atrial natriuretic peptide Internal medicine cardiovascular system medicine hormones hormone substitutes and hormone antagonists Antidiuretic Circumventricular organs medicine.drug |
| Zdroj: | Experimental Physiology. 92:903-911 |
| ISSN: | 0958-0670 |
| Popis: | The presence of nitric oxide synthase (NOS), the enzyme that catalyses the formation of nitric oxide (NO), in the circumventricular organs and magnocellular neurones suggests an important role of NO in the modulation of vasopressin (AVP) and oxytocin (OT) release. Intracerebroventricular (I.C.V.) injection of angiotensin II (Ang II) stimulates the release of AVP, OT and atrial natriuretic peptide (ANP), with the resultant antidiuretic and natriuretic effects. This study investigated the interaction between nitrergic and angiotensinergic pathways on the release of AVP, OT and ANP and on urinary volume and sodium excretion in water-loaded rats. Unanaesthetized, freely moving, male Wistar rats received two water loads followed by an injection into the lateral ventricle of an inhibitor of NOS (L-NAME), a NO donor [3-morpholinylsydnoneimine chloride (SIN-1) or S-nitroso-N-acetyl penicillamine (SNAP)] or vehicle (isotonic saline) and, 20 min after, they received a second I.C.V. injection of Ang II or vehicle. Injections of L-NAME or Ang II produced an increase in plasma levels of AVP, OT and ANP, a reduction in urinary volume and an increase in sodium excretion. Pretreatment with L-NAME enhanced the Ang II-induced increase in AVP, OT and ANP release, as well as the antidiuresis and natriuresis. Injection of SIN-1 or SNAP did not modify hormonal plasma levels and urinary parameters. In contrast SNAP blocked the AVP, OT and ANP release, as well as antidiuretic and natriuretic responses induced by ANG-II. Thus, the central nitrergic system can act to inhibit AVP, OT and ANP secretion and the antidiuretic and natriuretic effects in response to Ang II. |
| Databáze: | OpenAIRE |
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