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Sympathetic innervation of the splanchnic region is necessary for the beneficial effects of 5HT‐1A receptor agonists in rats during hypovolemic shock
Author(s) -
Tiniakov Ruslan L,
Scrogin Karie E
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.957.7
Subject(s) - splanchnic , shock (circulatory) , splanchnic nerves , mean arterial pressure , medicine , anesthesia , endocrinology , blood pressure , mean circulatory filling pressure , saline , splanchnic circulation , agonist , chemistry , hemodynamics , central venous pressure , heart rate , receptor , stimulation
The 5‐HT1A agonist, 8‐OH‐DPAT, improves blood gases following hemorrhagic shock via sympathetic‐dependent increases in venous return. To determine if this response requires sympathetic innervation of the splanchnic region, effects of 8‐OH‐DPAT (30 nmol/kg, iv) or saline on arterial pressure (AP), mean circulatory filling pressure (MCFP, an index of venous tone) and blood gases were determined in splanchnic‐denervated (SD) and sham‐operated rats during hemorrhagic shock (50 mmHg, 25 min). 8‐OH‐DPAT produced a rapid pressor effect in intact‐ (n= 7) and SD (n= 7) rats (+26 ± 3 and +21 ± 2 mmHg; P <0.01). However, the pressor effect was only transient in SD rats (~ 5 min). A persistent pressor effect was paralleled by increased MCFP in intact‐ (+2.2 ± 0.4 mmHg, 35 min after injection; P <0.01), but not SD rats. Saline had no effect on AP or MCFP. 8‐OH‐DPAT‐treated, intact rats had higher total bicarbonate (23 ± 2 vs. 14 ± 2, 12 ± 2, 16 ± 3 mmol/L; P <0.01) and lower lactate (7.7 ± 1.6 vs. 14.9 ± 1.5, 16.5 ± 1.8, 12.9 ± 2.1 mmol/L; P <0.01), compared to all other groups. The response to 8‐OH‐DPAT in hemorrhagic shock is dependent upon sympathetic innervation of the splanchnic region. Supported by HL 076162.