REPEATED EXPOSURE TO THE POLYCHLORINATED BIPHENYL (AROCLOR-1254) ELEVATES THE BASAL SERUM LEVELS OF CORTICOSTERONE BUT DOES NOT AFFECT THE STRESS-INDUCED RISE
Db. Miller et al., REPEATED EXPOSURE TO THE POLYCHLORINATED BIPHENYL (AROCLOR-1254) ELEVATES THE BASAL SERUM LEVELS OF CORTICOSTERONE BUT DOES NOT AFFECT THE STRESS-INDUCED RISE, Toxicology, 81(3), 1993, pp. 217-222
Previous studies indicate that repeated exposure of weanling male Fisc
her 344 rats to Aroclor can cause immune system alterations but the pa
ttern of effects suggested the release of corticosteroids may have pla
yed a role. Rats were exposed daily by gastric intubation to the polyc
hlorinated biphenyl (PCB) Aroclor 1254 at 0.1, 1.0, 10, or 25 mg/kg fo
r exposure durations of 5, 10 or 15 weeks. By the ]5th week of dosing
all groups displayed an elevation in the basal level of serum corticos
terone but no change in adrenal weight. Fur-ther, rats exposed to Aroc
lor 1254 for 15 weeks and subjected to stress prior to serum collectio
n displayed elevations in corticosterone levels equivalent to stressed
control rats. The failure to observe altered adrenal structure indica
tive of hyperactivity in the presence of increased serum levels of cor
ticosterone suggest these basal increases may be indirect rather than
direct effects of Aroclor 1254.