The role of the adrenals in the acute phase response to interleukin-1 and tumor necrosis factor-alpha.

ABSTRACT

The purpose of this study was to investigate the role of the adrenals, particularly the glucocorticoids, in the acute phase response following daily injections for 5 days of recombinant human interleukin-1 alpha,beta and tumor necrosis factor-alpha (TNF alpha). Adult weight-stable freely fed or pair-fed (to cytokine-injected mice) mice (C57Bl/6J) with and without adrenals were used. Adrenalectomized animals showed a sensitivity to both IL-1 alpha and -1 beta (40 ng IL-1/day) greater than 10-fold higher than that of normal mice (420 ng IL-1/day) in regard to mortality and anorexia. Microscopic examination of tissue specimens from adrenalectomized IL-1 alpha,beta-injected mice did not reveal any histologic alterations in lung, kidney, liver, brain, or gastrointestinal tract to explain the mortality. This mortality was not prevented by physiologic replacement doses of hydrocortisone (10-20 micrograms/day); however, a pharmacological dose of 2.5 mg hydrocortisone/day abolished completely the increased toxicity to IL-1 alpha,beta and the anorectic response to IL-1 alpha,beta and TNF alpha. Increased toxicity (mortality) was not observed in adrenalectomized animals with TNF alpha at the dose interval used (450 ng TNF alpha/day and lower). The hepatic acute phase response (liver weight and RNA and liver protein content) was increased by both IL-1 alpha,beta and TNF alpha in a glucocorticoid-independent way. The cytokine-induced alterations of plasma concentrations of acute phase proteins (serum amyloid P, transferrin, complement C3) were significantly dependent on glucocorticoids, while the decline in plasma albumin was not.(ABSTRACT TRUNCATED AT 250 WORDS)