Circulatory effects of RES depression in the dog

Abstract

The response of the anesthetized dog to single and repeated doses of colloidal carbon gel (CCG) is quite similar to that reported in other mammalian species. At doses less than 30 mg/kg the clearance rate is high and limited only by splanchnic blood flow. At dose levels above 30 mg/kg the phagocytic index (K) approaches a constant. The minimal dose of CCG for assessment of phagocytic capacity was adjudged to be 40 mg/kg. Large doses of CCG (160 mg/kg) and colloidal SiO2 (350 mg/kg) induced a phagocytic depression accompanied by a marked granulocytopenia as well as prompt and delayed hypotensive reactions. There was a decline of estimated splanchnic blood flow incident to test doses of CCG but no further reduction after a reticulo endothelial system RES-depressing dose of CCG. Colloidal thorium dioxide (4 and 8 ml/kg) did not depress the phagocytic capacity of the canine RES for CCG. It is suggested that the delayed hypotensive reaction may be related to the lesser tolerance to traumatic shock previously reported in RES-depressed animals.