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Splenic neural modulation of portal blood flow
Author(s) -
Hamza Shereen M,
Kaufman Susan E
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.a888-a
Subject(s) - medicine , splenic vein , denervation , anesthesia , blood flow , efferent , portal venous pressure , reflex , blood pressure , splenic artery , portal hypertension , mesenteric arteries , superior mesenteric artery , mesenteric vein , cardiology , anatomy , afferent , surgery , artery , portal vein , cirrhosis
Portal hypertension elevates splenic venous outflow pressure, which initiates a splenorenal reflex increase in renal sympathetic nerve activity and a reduction in renal blood flow. Portal hypertension also causes an increase in mesenteric vascular pressure. We hypothesized the associated rise in splenic venous pressure might initiate a spleno‐intestinal neural reflex to increase mesenteric vascular tone and reduce the flow of blood into the plethoric mesenteric vascular bed. The splenic vein was partially occluded so as to increase splenic venous pressure from 8.6±0.5 mmHg to 21.3±0.5 mmHg (n=14). This caused a significant fall in both portal venous flow (PVF) (−2.6±0.4 mL/min, n=7) and mesenteric vascular conductance (−0.0139±0.003 mmHg/mL·min −1 ). Splenic denervation significantly attenuated the fall in PVF (−0.67±0.1 mL/min, n=7) and in mesenteric vascular conductance (−0.003±0.001 mmHg/mL·min −1 ). Detailed analysis of the initial 3 minute period following splenic venous occlusion revealed that splenic denervation abolished the immediate drop in both PVF and mesenteric conductance, an effect not attributable to changes in systemic blood pressure (p<0.001). We conclude that elevated splenic venous pressure reflexly increases mesenteric arterial tone. We propose that this is mediated through the splenic afferent and mesenteric efferent nerves. (HSFC,CIHR)