Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 73: 224-233, 1992;
8750-7587/92 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Malvin, G. M.
Right arrow Articles by Wood, S. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Malvin, G. M.
Right arrow Articles by Wood, S. C.

Journal of Applied Physiology, Vol 73, Issue 1 224-233, Copyright © 1992 by American Physiological Society

ARTICLES

Effects of capillary red cell density on gas conductance of frog skin

G. M. Malvin and S. C. Wood
Oxygen Transport Program, Lovelace Medical Foundation, Albuquerque, New Mexico 87108.

We tested experimentally the hypothesis that decreasing capillary red blood cell (RBC) density (dRBC) reduces the tissue diffusing capacity of frog skin to CO (DtiCO) and O2 (DtiO2). The effects of dRBC on CO2 transport were also assessed. C18O, O2, and CO2 transport between the skin and a cutaneous sample chamber on the belly of anesthetized (halothane) frogs (Rana pipiens) was measured by mass spectrometry, and the cutaneous conductances to C18O (GCO), O2 (GO2), and CO2 (GCO2) were calculated. The dRBC of the planar cutaneous capillary bed was measured by intravital fluorescent video microscopy. DtiCO and DtiO2 were calculated from a modification of the Roughton-Foster equation: 1/G = 1/Dti + 1/(theta RBC.dRBC), where theta RBC values were estimated from literature values. In one group of animals (n = 6), measurements were made before hemodilution (dRBC = 630 +/- 56 cells/mm2), after one hemodilution (dRBC = 349 +/- 50 cells/mm2), and after a second hemodilution (dRBC = 150 +/- 31 cells/mm2). In controls, time had no effect on GCO, GO2, or GCO2 (P greater than 0.42). Before hemodilution, GCO, GO2, and GCO2 were 0.069 +/- 0.010, 0.088 +/- 0.0012, and 1.23 +/- 0.010 nmol.min-1.Torr-1.cm-2, respectively, and lowering dRBC by hemodilution decreased all these parameters (P less than 0.025). The mean slopes of GCO, GO2, and GCO2 vs. dRBC were 6.0 +/- 1.3 x 10(-7), 7.2 +/- 2.3 x 10(-7), and 7.8 +/- 3.0 x 10(-6) nmol.min-1.Torr-1.RBC-1, respectively. Lowering dRBC also decreased DtiCO and DtiO2 (P less than 0.034). DtiCO and DtiO2 were 0.080 +/- 0.012 and 0.096 +/- 0.013 nmol.min-1.Torr-1.cm-2, respectively, before hemodilution. The mean slopes of DtiCO and DtiO2 vs. dRBC were 4.9 +/- 2.1 x 10(-7) and 6.5 +/- 2.8 x 10(-7) nmol.min-1.Torr-1.RBC-1, respectively. Hemodilution had no effect on perfused capillary density (P = 0.38). These results indicate that tissue diffusive conductance is proportional to dRBC. Regulation of dRBC may be an important mechanism modulating diffusive gas transport in tissue.




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online