Research article

Arterial expression of 5-HT_2B and 5-HT_1B receptors during development of DOCA-salt hypertension

Amy KL Banes and Stephanie W Watts

Department of Pharmacology and Toxicology, Michigan State University, E. Lansing, MI 48824, USA

author email corresponding author email

BMC Pharmacology 2003, 3:12doi:10.1186/1471-2210-3-12

Published:	15 September 2003

Abstract

Background

5-hydroxytryptamine (5-HT)_2B and 5-HT_1B receptors are upregulated in arteries from hypertensive DOCA-salt rats and directly by mineralocorticoids. We hypothesized that increased 5-HT_2B and 5-HT_1B receptor density and contractile function would precede increased blood pressure in DOCA-high salt rats. We performed DOCA-salt time course (days 1, 3, 5 and 7) studies using treatment groups of: DOCA-high salt, DOCA-low salt, Sham and Sham-high salt rats.

Results

In isolated-tissue baths, DOCA-high salt aorta contracted to the 5-HT_2B receptor agonist BW723C86 on day 1; Sham aorta did not contract. The 5-HT_1B receptor agonist CP93129 had no effect in arteries from any group. On days 3, 5 and 7 CP93129 and BW723C86 contracted DOCA-high salt and Sham-high salt aorta; Sham and DOCA-low salt aorta did not respond. Western analysis of DOCA-high salt aortic homogenates revealed increased 5-HT_2B receptor levels by day 3; 5-HT_1B receptor density was unchanged. Aortic homogenates from the other groups showed unchanged 5-HT_2B and 5-HT_1B receptor levels.

Conclusion

These data suggest that functional changes of 5-HT_2B but not 5-HT_1B receptors may play a role in the development of DOCA-salt hypertension.