Role of AT1 and AT2 receptor subtypes in salt-sensitive hypertension induced by sensory nerve degeneration

Authors
Citation
Y. Huang et Dh. Wang, Role of AT1 and AT2 receptor subtypes in salt-sensitive hypertension induced by sensory nerve degeneration, J HYPERTENS, 19(10), 2001, pp. 1841-1846
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Journal title
JOURNAL OF HYPERTENSION
ISSN journal
0263-6352 → ACNP
Volume
19
Issue
10
Year of publication
2001
Pages
1841 - 1846
Database
ISI
SICI code
0263-6352(200110)19:10<1841:ROAAAR>2.0.ZU;2-R
Abstract
Objective To define the role of the type 1 angiotensin II (AT1) and type II (AT2) receptors in the development of salt-sensitive hypertension induced by sensory nerve degeneration. Design and methods Neonatal Wistar rats were given capsaicin 50 mg/kg s.c. on the first and second days of life. After weaning, male rats were divided into six groups and treated for 3 weeks with: control + high sodium diet ( 4%, CON-HS), capsaicin pretreatment + normal sodium diet (0.5%, CAP-NS), CA P-HS, CAP + HS + candesartan (10 mg/kg per day) (CAP-HS-CAN), CAP + HS + PD 123319 (30 mg/kg per day) (CAP-HS-PD), and capsaicin pretreatment + high s odium diet + candesartan + PD 123319 (CAP-HS-CAN-PD). Mean arterial pressur e (MAP) was measured by carotid arterial catheterization. Urinary Na+ conce ntrations were determined by using a flame atomic absorption spectrophotome ter. Levels of calcitonin gene-related peptide (CGRP) in dorsal root gangli a (DRG) and plasma renin activity (PRA) were determined by radioimmunoassay . Results CGRP contents in DRG were decreased by capsaicin (P < 0.05). MAP wa s higher in CAP-HS rats compared with all the other groups (P < 0.05). The 24 h urine and sodium excretion increased when a high salt diet was given, but they were lower in CAP-HS and CAP-HS-CAN than in CON-HS (P < 0.05). PRA was suppressed in CON-HS and CAP-HS compared with CAP-NS, but it was highe r in CAP-HS than in CON-HS (P < 0.05). Conclusion Insufficiently suppressed PRA by high salt intake may contribute to increased salt sensitivity and account for effectiveness of candesartan in lowering blood pressure in this model. Furthermore, PD 123319 attenuate s the development of hypertension in salt-loaded rats neonatally treated wi th capsaicin, indicating that the AT2 receptor contributes to the increase in blood pressure. (C) 2001 Lippincott Williams & Wilkins.