151. Brain Atrial Natriuretic Peptide Family Abolishes Cardiovascular Haemodynamic Alterations Caused By Hypertonic Saline In Rats
- Author
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Hakuo Takahashi, Masatoshi Sakamoto, and Masato Nishimura
- Subjects
Male ,Vasopressin ,medicine.medical_specialty ,Physiology ,Angiotensin Receptor Antagonists ,Atrial natriuretic peptide ,Physiology (medical) ,Internal medicine ,Natriuretic Peptide, Brain ,Renin–angiotensin system ,medicine ,Animals ,Rats, Wistar ,Saline Solution, Hypertonic ,Pharmacology ,Receptors, Angiotensin ,Angiotensin II receptor type 1 ,business.industry ,Hemodynamics ,Natriuretic Peptide, C-Type ,Angiotensin II ,Rats ,Hypertonic saline ,medicine.anatomical_structure ,Endocrinology ,Regional Blood Flow ,Vascular resistance ,Tonicity ,Vascular Resistance ,business ,Atrial Natriuretic Factor ,hormones, hormone substitutes, and hormone antagonists - Abstract
SUMMARY 1. Regional haemodynamic alterations caused by hypertonic NaCl solution (Hi-Salt; 10%, 10 μL) injected intracerebroventricularly (i.c.v.) were investigated by using radioactive microspheres in anaesthetized rats. 2. Intracerebroventricular injections of Hi-Salt increased regional vascular resistance of visceral organs, including the kidney, and elevated plasma levels of vasopressin. 3. Intracerebroventricular pretreatment with TCV-11974 (50 μg/10 μL/nat), an angiotensin AT1 receptor antagonist, attenuated the pressor response and vasopressin release to subsequently injected Hi-Salt, but did not affect regional haemodynamic effects of i.c.v. Hi-Salt on vascular resistance. 4. In contrast, i.c.v. pretreatment with atrial natriuretic polypeptide (ANP) or type-C natriuretic polypeptide (CNP) almost completely abolished the haemodynamic changes and vasopressin release caused by i.c.v. Hi-Salt. 5. The present findings indicate that a natriuretic family in the brain may be involved to a great degree in the central regulation of salt-induced hypertension in rats, while brain angiotensin II is likely to participate only in vasopressin release.
- Published
- 1999