In vivo administration of recombinant growth hormone or gamma interferon activities macrophages: enhanced resistance to experimental Salmonella typhimurium infection is correlated with generation of reactive oxygen intermediates

Abstract

Purified and recombinant forms of growth hormone (GH) as well as of recombinant rat gamma interferon (IFN-y) enhance the survival of rats deprived of endogenous pituitary GH secretion by hypophysectomy (HX rats) and infected with virulent SalmoneUla typhimurium. Macrophages obtained from rats with intact pituitaries (pituitary-intact rats) or HX rats that were treated in vivo with either GH or the closely related hormone prolactin released elevated (P < 0.05) levels of superoxide anion (02-) after in vitro opsonizedzymosan stimulation compared with those from placebo-treated animals. These levels of 02 release were similar in magnitude to those of macrophages from rats treated in vivo with IFN-y. In time course in vivo macrophage activation studies, both IFN-'y and GH significantly increased°2secretion within 24 h, with maximal secretion occurring at day 3. Macrophages obtained from pituitary-intact and HX rats injected in vivo with GH also released elevated (P < 0.05) levels of hydrogen peroxide (H202) and displayed enhanced (P < 0.01) phagocytic activity toward opsonized Listeria monocytogenes in vitro. The mechanism of action of GH in vivo is likely to be a direct one because resident peritoneal macrophages from rats could be primed in vitro for enhanced secretion of 02 following triggering of these cells with opsonized zymosan. These data show that in vivo administration of two closely related pituitary hormones, GH and prolactin, can effectively prime macrophages, which is consistent with the hypothesis that GH mediates resistance to S. typhimurium by a direct stimulatory action on macrophages.

Sleep of transgenic mice producing excess rat growth hormone

“…Thereafter, SWA declined rapidly and was slightly below baseline at the end of the night. The changes in SWA were significant in both groups [controls: F(1,7) ϭ 17.23, P Ͻ 0.005; MT-rGH mice: F(1,9) ϭ 17.23, P Ͻ 0.005] and varied with time [controls: F(11,77) ϭ 25.25, P Ͻ 0.0001; MT-rGH mice: F (11,99) ϭ 25.25, P Ͻ 0.0001] without differences between the normal and the MT-rGH mice.…”

Effector molecules of the host defence mechanism against Mycobacterium avium complex: the evidence showing that reactive oxygen intermediates, reactive nitrogen intermediates, and free fatty acids each alone are not decisive in expression of macrophage antimicrobial activity against the parasites

“…First, concerning reactive oxygen intermediates (ROI), a well known effect of macrophage antimicrobial activity against Listeria monocytogenes and Salmonella typhimurium [5,6], their participation in killing and growth inhibition of mycobacteria, including M. tuberculosis and MAC, is reported to be relatively small [7][8][9][10][11]. Indeed, a xanthine oxidase-acetaldehyde system which enzymatically generates ROI molecules (O 2 ¹ , H 2 O 2 , .…”

Growth hormone stimulates the degradation of calcium phosphate biomaterial by human monocytes macrophagesin vitro

“…Indeed GH, described as a macrophage-activating factor implicated in the priming of monocytes/macrophages for production of the key mediator of the inflammatory process, 25 also has been found to increase the phagocytic activities of macrophage polykaryons via superoxide production. 26,27 These recent data, together with the observation that pretreatment with GH activated phagocytic cells and stimulated systemic cytokine production in a mouse sepsis model, 28 suggest that GH is involved in the inflammation process. These findings indicate that GH could play a role in the biodegradation process of CaP ceramic not only through osteoclasts but also through stimulation of the monocyte/macrophage lineage.…”