| Splenorenal reflex modulates renal blood flow in the rat. | |
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MedLine Citation:
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PMID: 15090605 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We have previously shown that the splenorenal reflex controls renin release through splenic afferent and renal sympathetic nerves. We proposed that this reflex would also affect renal blood flow (RBF). RBF was measured in male Long Evans rats using transit-time flow probes. There were no significant differences between any of the experimental groups with respect to baseline values of RBF (8.9 +/- 0.4 ml min(-1), n= 25) or mean arterial pressure (MAP, 98.7 +/- 2.5 mmHg, n= 25). Splenic venous pressure was selectively raised (from 7.9 +/- 0.6 to 21.6 +/- 0.3 mmHg, n= 25) in anaesthetized rats by partial ligation of the splenic vein. This caused an immediate fall in RBF (-2.1 +/- 0.2 ml min(-1), n= 7) and in MAP (-12.4 +/- 2.8 mmHg, n= 7). The fall in RBF, but not the fall in blood pressure, was attenuated by renal denervation (DeltaRBF: - 0.7 +/- 0.1 ml min(-1), n= 6), splenic denervation (DeltaRBF: -0.8 +/- 0.1 ml min(-1), n= 6) and close renal arterial injection of the alpha1-adrenergic blocker phenoxybenzamine (12.5 microg; DeltaRBF: -0.8 +/- 0.1 ml min(-1), n= 6). Renal conductance fell only in the intact control group, i.e. the residual fall in RBF in the denervated and phenoxybenzamine-treated animals could be attributed to the fall in MAP. We also showed that splenic vein occlusion increased both splenic afferent (from 3.0 +/- 0.3 to 6.6 +/- 0.6 spikes s(-1), n= 5) and renal efferent (from 24.8 +/- 2.0 to 50.2 +/- 4.9 spikes s(-1), n= 9) nerve activity. We conclude that obstruction to splenic venous outflow, such as would occur in portal hypertension, initiates increased splenic afferent nerve activity and renal vasoconstriction through the splenorenal reflex, as well as a fall in blood pressure. We propose that this contributes to the renal and cardiovascular dysfunction observed in portal hypertension. |
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Authors:
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Shereen M Hamza; Susan Kaufman |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2004-04-16 |
Journal Detail:
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Title: The Journal of physiology Volume: 558 ISSN: 0022-3751 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 2004 Jul |
Date Detail:
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Created Date: 2004-06-30 Completed Date: 2005-01-19 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 0266262 Medline TA: J Physiol Country: England |
Other Details:
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Languages: eng Pagination: 277-82 Citation Subset: IM |
Affiliation:
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Department of Physiology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Pressure / physiology Denervation Male Neurons, Afferent / physiology Neurons, Efferent / physiology Rats Rats, Long-Evans Receptors, Adrenergic, alpha-1 / physiology Reflex / physiology* Renal Circulation / physiology* Renin / blood Spleen / blood supply, innervation*, physiology Splenic Vein / physiology Venous Pressure / physiology |
| Chemical | |
Reg. No./Substance:
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0/Receptors, Adrenergic, alpha-1; EC 3.4.23.15/Renin |
| Comments/Corrections | |
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