Premium
The 5‐HT1A‐receptor agonist, 8‐OH‐DPAT, increases cardiac output and renal blood flow in conscious rats during hypovolemic shock
Author(s) -
Tiniakov Ruslan,
OseiOwusu Patrick,
Scrogin Karie
Publication year - 2006
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.20.5.a1385-c
Previous studies have shown that the 5‐HT1A‐receptor agonist, 8‐OH‐DPAT, raises blood pressure (BP), sympathetic activity and venous tone in conscious rats after hypotensive hemorrhage. To determine if 8‐OH‐DPAT produces a favorable hemodynamic response during circulatory shock, BP, heart rate (HR) and ascending aortic blood flow (i.e., cardiac output, CO) were measured during hypotensive hemorrhage (rapid blood withdrawal to 50 mm Hg maintained for 30 min) and subsequent injection of 8‐OH‐DPAT (30 nmol/kg, iv, n=7) or saline (n=5) in conscious, unrestrained rats. Blood pressure, renal‐ (RBF) and iliac blood flow (IBF) were measured in separate groups of rats (n=11 and 10 for 8‐OH‐DPAT and saline groups respectively). Hemorrhage rapidly reduced BP (−63±6 mmHg), HR (−164±15 bpm), CO (−132±15 ml/min/kg), RBF (−2.03±0.3 ml/min) and IBF (−2.27±0.32 ml/min) 6 min after start of blood withdrawal. With sustained hypotension, CO, RBF and IBF continued to fall while HR and TPR rose. Subsequent 8‐OH‐DPAT injection raised BP (+30 ± 5 vs. +12 ± 3 mm Hg, P<0.01), CO (+26 ± 5 vs. +11 ± 7 ml/min/kg, P<0.01) and RBF (+0.9 ± 0.2 vs. +0.5 ± 0.1 ml/min, P<0.01) to a greater extent than saline 15 min after injection, but had no significant effect on IBF or TPR. 8‐OH‐DPAT also raised renal‐ (+0.007 ± 0.001 vs. +0.004 ± 0.001 ml/min/mmHg, P<0.01), but not iliac conductance to a greater extent than saline. We conclude that 8‐OH‐DPAT produces a favorable hemodynamic effect during circulatory shock through mobilizition of blood stores and renal vasodilation. Supported by HL 076162, 072354 and AHA 0310026Z.