• Microvascular research · Sep 2009

    Hepatic microvascular pressure during anaphylactic shock in anesthetized rats.

    • Hiromichi Takano, Toshishige Shibamoto, Wei Zhang, Yasutaka Kurata, and Hirohisa Toga.
    • Department of Physiology II, Kanazawa Medical University, Uchinada 920-0293, Japan.
    • Microvasc. Res. 2009 Sep 1; 78 (2): 169-73.

    ObjectiveHepatic venoconstriction plays a significant role in anaphylactic hypotension in anesthetized rats. The purpose of this study is to determine whether the primary site of anaphylactic venoconstriction in the liver venous circulation occurs prior to or distal to the sinusoidal capillaries. We also determined whether the hepatic blood volume is increased during anaphylactic hypotension.MethodsWe measured, using a servo-null micropipette pressure-measuring system, the hepatic venular transmural pressure (P micro hv) at the liver surface of anesthetized rats sensitized with the antigen of ovalbumin (1 mg). We also measured the liver lobe thickness, using the ultrasonic crystal dimension measuring system. Anaphylactic hypotension was induced by an intravenous injection of 0.6 mg ovalbumin.ResultsWhen the antigen was injected, the systemic arterial pressure decreased profoundly from 118+/-9 to 45+/-4 mm Hg, which was accompanied by an increase in Ppv and P micro hv: P micro hv only transiently increased from 3.1+/-0.9 to 8.8+/-1.5 cm H(2)O at 1 min and then rapidly returned to the baseline within 2 min, when Ppv continued to increase and reached the peak of 36+/-7 cm H(2)O at 3.5 min after antigen. This greater increase in Ppv-to-P micro hv gradient than that in P micro hv-to-Pcv gradient after antigen indicated that the constriction of the portal veins and the sinusoids much predominates over that of the hepatic veins. Along with this hepatic pre- and sinusoidal constriction, the liver lobe thickness significantly decreased by 4% after antigen.ConclusionPre-sinusoidal constriction during anaphylactic shock in anaesthetized rats increased the portal venous pressure while the hepatic venular pressure only increased slightly and transiently. This predominant pre-sinusoidal constriction is accompanied by a decrease in liver volume.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…