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Acta Physiologica 2011; Volume 202, Supplement 685
Scandinavian Physiological Society's Annual Meeting
8/12/2011-8/14/2011
Bergen, Norway
ACETYLCHOLINE SENSITIVITY IN ABDOMINAL SUBCUTANEOUS ARTERIES FROM OBESE PATIENTS
Abstract number: 6.1.5
BRONDUM1 ET, GRUNNET1 M, BORG1 M, RAMLOV1 P, FUNCH-JENSEN1 P, AALKJAER1 C
1Institute of Biophysics, Aarhus University, Ole Worms All build 1160, 8000 Aarhus C, Denmark; Email: [email protected]
Background:
Patients with obesity have an increased risk for cardiovascular disease, possibly related to endothelial-dysfunction. This study investigates the acetylcholine mediated relaxation in subcutaneous resistance arteries from obese patients (BMI>40) undergoing gastric-bypass operation or undergoing surgery for non-cardiovascular related reasons. (i.e. kidney transplant donors).
Methods:
Arteries dissected from biopsies taken from 12 control and 12 obese matched for age and sex were mounted in an isometric myograph. Endothelium-dependent relaxation was investigated by increasing concentrations of acetylcholine on noradrenaline pre-contracted vessels. The EDHF-like response was investigated in the presence of eNOS and COX inhibitors and pharmacological modulators of the pathways involved in the EDHF response.
Results:
There was no difference between the groups in maximal relaxation under control conditions (86±6 and 89±3%, obese and control, respectively). However, the sensitivity to acetylcholine was significantly higher in obese (logEC50 was -7.4±0.1and -7.1±0.1, obese and control, respectively (p =0.02)). Also after blocking eNOS and COX the sensitivity to acetylcholine was higher in obese (logEC50 -6.6±0.1 and -6.2±0.1 (p =0.02)) while maximal relaxation was not different (61±9 and 70±4%(p> 0.5), obese and control, respectively). Treatment with the IK and SK channel opener NS309 (1mM) abolished the difference in sensitivity (logEC50 -7.3±0.1 and -7.2±0.2) while increasing maximal relaxation (77±4 and 79±14%, n= 11 and 3) obese and control, respectively.
Conclusions:
Subcutaneous resistance arteries from obese patients seem to have increased sensitivity to the endothel.
To cite this abstract, please use the following information:
Acta Physiologica 2011; Volume 202, Supplement 685 :6.1.5