Regulation of tumour necrosis factor production by adrenal hormones in vivo: insights into the antiinflammatory activity of rolipram

Open Access
Publisher Website
Google Scholar
Abstract
1 The role of adrenal hormones in the regulation of the systemic and local production of tumour necrosis factor (TNFα) was examined in male Balb/c mice. 2 Intraperitoneal injection of 0.3 mg E. coli lipopolysaccharide (LPS, 0111:B4) led to high levels of circulating TNFa without stimulating TNFa production in the peritoneal cavity. Systemic production of TNFα in response to LPS was increased in adrenalectomized animals and in normal animals treated with the β-adrenoceptor antagonist, propranolol. The glucocortoid antagonist, RU 486, did not modify systemic TNFα production. These results indicate that systemic TNFα production is regulated by adrenaline but not by corticosterone. 3 When mice were primed with thioglycollate, TNFα was produced in the peritoneal cavity in response to low dose LPS (1 μg). The levels of TNFα in the peritoneal cavity were not enhanced by adrenalectomy or by treatment with either propranolol or RU 486, indicating local production of TNFα in the peritoneal cavity is not regulated by adrenaline or corticosterone. 4 The phosphodiesterase type IV (PDE-IV) inhibitor, rolipram, inhibited both the systemic production of TNFa in response to high dose endotoxin (ED50 = 1.3 mg kg−1) and the local production of TNFα in the peritoneal cavity in response to low dose endotoxin (ED50 = 9.1 mg kg−1). In adrenalectomized mice there was a slight reduction in the ability of rolipram to inhibit the systemic production of TNFα (ED50 = 3.3 mg kg−1) while the ability of rolipram to inhibit the local production of TNFα in the peritoneal cavity was virtually abolished (24% inhibition at 30 mg kg−1). The glucocorticoid antagonist, RU 486, also reduced the ability of rolipram to inhibit local TNFα production while propranolol was without effect. 5 Systemic treatment with rolipram increased the plasma concentrations of corticosterone in normal mice but not in adrenalectomized mice indicating that rolipram can cause adrenal stimulation in vivo. 6 In summary, these data indicate that systemic production of TNFα in response to high dose endotoxin is controlled differently from the local production of TNFα in response to low dose endotoxin. The systemic production of TNFα is regulated by catecholamines, but not by corticosterone, while the local production of TNFα in the peritoneal cavity is not regulated by basal levels of either catecholamines or corticosterone. 7 These data also show that the ability of rolipram to inhibit the local production of TNFα is dependent on the release of corticosterone from the adrenal glands.

This publication has 28 references indexed in Scilit: