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Additive impairment of beta‐adrenoceptor‐mediated renal vasodilation by nicotine and cyclosporine
Author(s) -
Elgowilly Sahar M,
Ghazal AbdelRheem M,
Goher Eman Y,
ElMas Mahmoud M
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1129.10
Subject(s) - isoprenaline , propranolol , hexamethonium , nicotine , phenylephrine , nifedipine , pharmacology , vasodilation , chemistry , endocrinology , medicine , blood pressure , acetylcholine , calcium , stimulation
We tested the hypothesis that nicotine aggravates the deleterious effect of the immunosuppressant drug cyclosporine (CSA) on β‐adrenoceptor‐mediated renovascular control. The effect of nicotine alone or combined with CSA on isoprenaline vasodilation in phenylephrine‐preconstricted perfused rat kidneys was assessed. Bolus isoprenaline (0.25 μmol) caused 35.4±4.0% reduction in the phenylephrine‐induced tone, which was attenuated by propranolol and tetraethylammonium (TEA), potentiated by hexamethonium and diclophenac, and abolished in KCl‐preconstricted tissues. N G ‐nitro‐L‐arginine (L‐NNA), methylene blue, CHAPS, nifedipine, or SQ22,536 had no effect on isoprenaline vasodilation. Nicotine infusion caused 30.2±3.6% reduction in isoprenaline vasodilation and this effect was potentiated when CSA was concomitantly infused with nicotine. The effect of nicotine on isoprenaline vasodilation was reduced by hexamethonium and potentiated by L‐NNA, methylene blue, CHAPS, or nifedipine. The CSA exacerbation of nicotine‐isoprenaline interaction was abolished by propranolol, L‐NNA, methylene blue, CHAPS, L‐arginine, TEA, or nifedipine. It is concluded that nicotine and CSA produce additive impairment of β‐adrenoceptor‐mediated renovascular control and implicated the endothelial NO/K + pathway in the interaction. Supported by Faculty of Pharmacy, Univ. of Alexandria, Egypt.