Endotoxin-induced interleukin 1 expression in testicular macrophages is accompanied by downregulation of the constitutive expression in Sertoli cells.
Interleukin-1alpha (IL-1alpha) is constitutively produced by Sertoli cells in adult rat testes. We demonstrate here that adult rats initiate expression of IL-1alpha and IL-1beta in testicular macrophages and decrease plasma testosterone by 60%, 2 h after administration of endotoxin. The macrophage activation was accompanied by downregulation of IL-1alpha mRNA expression in Sertoli cells. Despite increased tissue concentrations of IL-1alpha and IL-1beta immunoreactive protein, the level of bioactive IL-1 in the testis remained unchanged. Testes from prepubertal rats responded similarly to endotoxin, but lacked constitutive expression of IL-1alpha. We conclude that endotoxin-induced inflammation involves the testis by local macrophage activation and cytokine secretion. The paracrine mechanisms regulating IL-1 bioactivity in the testis are unknown but may represent a means to protect germ cells from noxious effects of inflammation.
Jonsson
C K
CK
Department of Woman and Child Health, Astrid Lindgren Children's Hospital, Stockholm, Sweden. cecilia.jonsson@kbh.ki.se
Setchell
B P
BP
Martinelle
N
N
Svechnikov
K
K
Söder
O
O
D000818:Animals; D015536:Down-Regulation; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007249:Inflammation / Q000196:embryology; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012708:Sertoli Cells / Q000187:drug effects / Q000276:immunology*; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D013737:Testis / Q000166:cytology / Q000276:immunology*
D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D012795:Sialoglycoproteins