AJP - Regulatory, Integrative and Comparative Physiology, Vol 232, Issue 3 80-R87, Copyright © 1977 by American Physiological Society
Electroimmunoassay of alpha-2-opsonic protein during reticuloendothelial blockade
F. Blumenstock, P. Weber, T. M. Saba and R. Laffin
Physiological regulation of reticuloendothelial (RE) phagocytic activity by
a plasma opsonic factor has been documented. In the recent study, serum
levels of this alpha-2-opsonic protein in rats during colloid-induced RE
blockade were measured utilizing an electroimmunoassay (Rocket
immunoelectrophoresis) with monospecific antiserum to the purified
alpha-2-glycoprotein. RE blockade was produced by the intravenous injection
of the gelatinized "RE-test-lipid emulsion" at a dose of 50 mg/100 g body
wt. The opsonic activity of serum at various intervals during
colloid-induced RE blockade as measured by tissue slice bioassay manifested
a high correlation (r = 0.98) with the serum opsonic protein concentration
as measured by the electroimmunoassay. During RE blockade (30 min), there
was a rapid depletion of the opsonic alpha-2-glycoprotein to 20% of the
initial preinjection levels. Serum concentration of this glycoprotein
remained low for at least 2-3 h after which time its concentration
progressively increased with approximation of normal values by 6 h
postblockade. Opsonic protein concentration at 24 h postinjection were
significantly (P less than 0.05) elevated above controls. Thus,
colloid-induced RE blockade is associated with the removal of this
glycoprotein from the serum and recovery from RE blockade is accompanied by
a restoration of opsonin levels. The electroimmunoassay can provide a
sensitive technique to monitor this humoral factor known to exert a
physiological control on the RE system.
