AJP - Endocrinology and Metabolism, Vol 250, Issue 1 69-E75, Copyright © 1986 by American Physiological Society
Effect of rate of hemorrhage on sympathoadrenal catecholamine release in cats
D. A. Bereiter, A. M. Zaid and D. S. Gann
The effect of rate of blood loss on catecholamine release and
cardiovascular compensation to hemorrhage (H) was assessed in
alpha-chloralose-urethane anesthetized cats. Arterial blood was withdrawn
at a rapid rate (10% measured blood vol/min) or at a slow rate (2%/min),
and responses were compared across three volumes of hemorrhage (10, 20, or
30% of total blood vol). Plasma epinephrine did not increase after 10% H,
but increased modestly after rapid (199 +/- 25 pg/ml) or slow 20% H (359
+/- 92 pg/ml). In contrast, rapid 30% H evoked a significantly (P less than
0.01) greater increase in epinephrine than slow 30% H (1,827 +/- 274 vs.
630 +/- 165 pg/ml). The rate of hemorrhage had no differential effect on
hemorrhage-evoked plasma norepinephrine, but a graded increase was seen
with increasing volume of hemorrhage. Similarly, hemorrhage-evoked plasma
glucose was proportional to the volume of hemorrhage and was not affected
by rate of hemorrhage. Volume of hemorrhage was a good indicator of
norepinephrine release after rapid or slow rate of hemorrhage, whereas
epinephrine release was well correlated with the mean changes in blood
pressure during the posthemorrhage sampling period after rapid or slow rate
of hemorrhage. The data indicate that hemorrhage-evoked release of
epinephrine depends on the rate of blood loss, but only after large (30%)
volumes of hemorrhage. Norepinephrine released into the peripheral
circulation demonstrates no dependency on rate of hemorrhage, but is well
correlated with volume of hemorrhage.(ABSTRACT TRUNCATED AT 250 WORDS)
