The objectives of this study were (1) to measure plasma (V(p)), blood (V(b)), extracellular (V(e)), and interstitial fluid (V(ist)) volumes using the same techniques; (2) to measure the rate of plasma turnover; and (3) to characterize the three important variables required to interpret transvascular flux at an organismal level (vascular compliance [C(vas)], interstitial compliance [C(ist)], and the whole-body transvascular filtration coefficient [F(c)]) in two species of anurans that differ in their capacity to regulate blood volume during dehydrational and hemorrhagic stress. The disappearance curve of Evans blue-labeled native plasma protein fitted a two-component exponential decay model for both species, indicating that plasma proteins exchanged quickly between two kinetically distinct compartments, V(p) and V(e). V(p) calculated using serial sampling times <10 min were 61.
View Article and Find Full Text PDFPhysiol Biochem Zool
December 2004
The effects of hypervolemia and graded increases in arginine vasotocin (AVT), angiotensin II (ANGII), and atrial natriuretic peptide (ANP) on lymph heart pressure (P(lh)) and rate (f(lh)) were examined in Bufo marinus and Rana catesbeiana. The P(lh) and f(lh) for normally hydrated B. marinus at rest were 1.
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