| In vivo microperfusion of the ductuli efferentes testis of the rat: flow dependence of fluid reabsorption. | |
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MedLine Citation:
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PMID: 8853271 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Individual ducts from the initial zone of the efferent ducts of the rat were microperfused in vivo using a double cannulation procedure, which allowed the recovery of perfused fluids for analysis and determination of the rate of fluid reabsorption from the perfused duct. The ducts were perfused at rates from 0.025 to 0.4 microliters min-1 with either Krebs-Ringer bicarbonate (KRB) solution or the native rete testis fluid (nRTF) that perfuses the ducts in situ. Reabsorption of KRB solution increased linearly with a perfusion rate of between 0.025 and 0.1 microliter min-1 (from 17.4 +/- 1.5 to 34.3 +/- 3.2 nl (10 mm duct)-1 min-1), then increased no further. Reabsorption of nRTF increased linearly between 0.025 and 0.2 microliters min-1 (from 17.7 +/- 1.5 to 61.4 +/- 13.5 nl (10 mm duct)-1 min-1) and then declined. The reabsorption rate from nRTF perfusates was significantly higher than from KRB perfusates. As a proportion of the luminal perfusate, reabsorption declined from 73.0 +/- 6.0 to 7.4 +/- 3.0% (10 mm duct)-1 for KRB solution and from 73.1 +/- 6.0 to 4.1 +/- 1.3% (10 mm duct)-1 for nRTF. There was no significant change in the concentration of either Na+ or Cl- in KRB solution or nRTF during perfusion through the efferent ducts, indicating that the reabsorption of these ions was isomolar. However, the reabsorption of K+ from nRTF occurred at a greater rate than that of water, and the initial [K+] declined from 17.2 +/- 0.4 mM in nRTF perfusates to 5.7 +/- 0.5 mM in collectates (perfusion rate, 0.1 microliter min-1) to achieve equilibrium with blood plasma (4.7 +/- 0.4 mM). The osmotic pressure of both KRB and nRTF perfusates equilibrated with blood plasma, indicating a high permeability of the epithelium to water. The results of this study provide further evidence that fluid reabsorption in the efferent ducts is isosmotic, or close to isosmotic, and have shown that, as in the homologous proximal kidney tubule, reabsorption is dependent on luminal flow rate. In contrast to the proximal tubule, however, reabsorption in the efferent ducts is not maintained as a constant proportion of the perfusion load. It is concluded that microperfusion in vivo provides a useful technique for studying fluid reabsorption in the efferent ducts of the rat. |
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Authors:
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J Clulow; L A Hansen; R C Jones |
Publication Detail:
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Type: In Vitro; Journal Article |
Journal Detail:
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Title: Experimental physiology Volume: 81 ISSN: 0958-0670 ISO Abbreviation: Exp. Physiol. Publication Date: 1996 Jul |
Date Detail:
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Created Date: 1997-01-03 Completed Date: 1997-01-03 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 9002940 Medline TA: Exp Physiol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 633-44 Citation Subset: IM |
Affiliation:
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Department of Biological Sciences, University of Newcastle, NSW, Australia. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Absorption Animals Body Fluids / physiology Ejaculatory Ducts / physiology* Electrolytes / metabolism Kidney Tubules, Proximal / cytology, drug effects, metabolism Male Osmotic Pressure Perfusion Potassium Channels / drug effects, metabolism Proteins / metabolism Rats Rats, Wistar |
| Chemical | |
Reg. No./Substance:
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0/Electrolytes; 0/Potassium Channels; 0/Proteins |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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