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Chronic 5‐HT: An unexpected depressor in mineralocorticoid hypertension
Author(s) -
Diaz Jessica,
Ni Wei,
King Andrew,
Fink Gregory D,
Watts Stephanie W
Publication year - 2007
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.21.6.a897
Subject(s) - blood pressure , medicine , endocrinology , mineralocorticoid , serotonin , aldosterone , 5 ht receptor , mean arterial pressure , heart rate , receptor
Serotonin (5‐HT) is a vasoactive autocoid, but its role in systemic blood pressure regulation is unclear. The role of 5‐HT in hypertension is not understood though arteries from different models of hypertension are hypercontractile to 5‐HT. We hypothesized that chronic 5‐HT infusion would lead to increased blood pressure and arterial 5‐HT content in normotensive rats; these responses would be enhanced in deoxycorticosterone acetate (DOCA)‐salt hypertensive rats. 5‐HT (25 ug/kg/min) or vehicle was administered via osmotic pump for 1 week to normotensive and established hypertensive rats. Within 24 hours post‐pump implantation, radiotelemeter measurement of mean arterial pressure in the normotensive 5‐HT infused group fell 23 mmHg (table). This hypotensive response was enhanced in the DOCA 5‐HT infused group in which mean arterial pressure fell 63 mmHg. These findings are the first to demonstrate the long‐term effects of 5‐HT on blood pressure, and indicate the net effect of chronic increases in circulating 5‐HT is decreased blood pressure. This is counterintuitive given arterial hyperresponsiveness to 5‐HT in vivo and in vitro , suggesting the effects of 5‐HT in the cardiovascular system are considerably more complex than currently appreciated. Mean Arterial Pressure (mmHg)