Details

Autor(en) / Beteiligte

• Hoehle, S
• Spitznagel, H
• Rascher, W
• Culman, J
• Unger, T

Titel

Angiotensin AT sub(1) receptor-mediated vasopressin release and drinking are potentiated by an AT sub(2) receptor antagonist

Ist Teil von

• European journal of pharmacology, 1995-03, Vol.275 (3), p.277-282

Erscheinungsjahr

1995

Link zum Volltext

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• Stimulation of angiotensin II AT sub(2) receptors has been shown to inhibit AT sub(1) receptor-mediated actions in peripheral tissues. The role of AT sub(2) receptors in the central actions of angiotensin is not well understood. In the present study, plasma vasopressin levels and water intake in response to intracerebroventricular angiotensin II (10 pmol) were determined after intracerebroventricular pretreatment with PD 123177 (1-(4-amino-3-methylphenyl)methyl -5-diphenylacetyl-4,5,6,7-tetrahydro-1H-imidazo [4,5-c]pyridine-6-carboxylic acid-2HCl), a selective AT sub(2) receptor antagonist (10, 100 and 1000 pmol), or with losartan (2-n-butyl-4-chloro-5-hydroxy-methyl-1-2'- (1H-tetrazole-5-yl)biphenyl-4-yl)methlimidazole, thylimidazole, potassium salt), a specific AT sub(1) receptor antagonist (0.2, 2 and 10 nmol). Blood samples for vasopressin determination were drawn 90 s after angiotensin II injection and the drinking response was determined in a time interval of 10 min after intracerebroventricular angiotensin II. Losartan at a dose of 2 nmol or higher completely prevented vasopressin release and drinking response to angiotensin II. The drinking response was already attenuated after pretreatment with the lowest dose of losartan. In contrast, PD 123177 potentiated the angiotensin II-induced vasopressin release (39.7 plus or minus 2.7 pg/ml after 1000 pmol PD 123177 vs. 21.3 plus or minus 2.9 pg/ml in vehicle-pretreated controls, P < 0.05). The dipsogenic response to angiotensin II was also potentiated by PD 123177 (9.5 plus or minus 0.7 ml after 1000 pmol PD 123177 vs. 5.1 plus or minus 1.3 ml in vehicle-pretreated controls, P < 0.05). Our results suggest that the angiotensin II-induced vasopressin release and drinking, mediated by central AT sub(1) receptors, are under inhibitory control by central AT sub(2) receptors.