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Bkca potassium channels and sympathetic transmission in the pulmonary artery from pulmonary hypertensive rats
Author(s) -
Oriowo Mabayoje,
ElHajj Hanadi
Publication year - 2009
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.23.1_supplement.579.3
Subject(s) - pulmonary artery , medicine , pulmonary hypertension , cardiology , potassium channel , stimulation , blood pressure , anesthesia
Pulmonary hypertension (PH) is a chronic disabling disease that affects the pulmonary vasculature. In this study, we have examined the effect of blocking potassium channels on sympathetic neurotransmission in the pulmonary artery and how this is influenced by PH. The right ventricular pressure was 30.4±3.5 mmHg and 52.8±5.4 mmHg in control and hypertensive rats respectively. These values were significantly different from each other indicating pulmonary hypertension. Electrical stimulation of the pulmonary artery produced frequency‐dependent contractions with LogES50 values of 1.13±0.18 and 0.44±0.26 in control hypertensive rats, respectively. There was no significant difference in the maximum response between the groups. TEA (1 mM), a BKca channel blocker, produced a nonsignificant increase in maximum response in control rat but produced a significant shift of the frequency‐response curve to the left reducing the LogES50 value from 1.13±0.18 to 0.37±0.32 (n=5). In hypertensive rats TEA (1 mM) shifted the frequency‐response curve to the left and significantly increased the maximum response. It was concluded that BKCA channels modulated adrenergic transmission in the rat pulmonary artery and this was not affected by pulmonary hypertension.