Objective—To determine whether cross-reactivity
exists between canine chromogranin A (CgA) and
anti-human CgA antibody and investigate the usefulness
of plasma CgA concentration measurements as
an index of acute stress responses in dogs.
Animals—12 healthy Beagles.
Procedure—Canine CgA was extracted and purified
from canine adrenal glands of cadaver dogs for studying
cross-reactivity with anti-human CgA antibody.
Western blotting with anti-human CgA antibody was
performed. Blood samples were collected from dogs
at 0, 10, 20, 30, 40, 60, 120, and 180 minutes after IV
administration of saline (0.9% NaCl) solution or
insulin. Canine plasma CgA concentrations were
determined by use of a CgA ELISA kit with rabbit antiserum
against the carboxy-terminal fragment of
human CgA. Plasma cortisol and catecholamine (ie,
norepinephrine and epinephrine) concentrations were
measured by use of an ELISA and a high-performance
liquid chromatography method, respectively.
Results—Purified canine CgA was specifically detected
by use of western blot analysis and an ELISA with
anti-human CgA antibody. An increase in plasma CgA
concentrations was observed in insulin-induced hypoglycemic
dogs. Changes in plasma CgA concentration
were correlated with changes in plasma cortisol or
catecholamine concentrations of hypoglycemic dogs.
Conclusions and Clinical Relevance—Use of the
CgA ELISA kit for determination of human plasma
CgA concentrations is applicable to the measurement
of canine plasma CgA concentrations. Canine plasma
CgA concentrations, along with measurements of
plasma cortisol and catecholamine concentrations,
correctly reflect insulin-induced hypoglycemic
stressed conditions in dogs. Measurement of canine
plasma CgA concentrations may provide a useful
index for evaluation of an acute stress response. (Am
J Vet Res 2005;66:1830–1835)