Sites of synthesis of urokinase and tissue-type plasminogen activators in the murine kidney.
AUTOR(ES)
Sappino, A P
RESUMO
Kidneys have long been recognized as a major source of plasminogen activators (PAs). However, neither the sites of synthesis of the enzymes nor their role in renal function have been elucidated. By the combined use of zymographies on tissue sections and in situ hybridizations, we have explored the cellular distribution of urokinase-type (u-PA) and tissue-type (t-PA) plasminogen activators and of their mRNAs in developing and adult mouse kidneys. In 17.5-d old embryos, renal tubules synthesize u-PA, while S-shaped bodies produce t-PA. In the adult kidney, u-PA is synthesized and released in urine by the epithelial cells lining the straight parts of both proximal and distal tubules. In contrast, t-PA is produced by glomerular cells and by epithelial cells lining the distal part of collecting ducts. The precise segmental distribution of PAs suggests that both enzymes may be implicated in the maintenance of tubular patency, by catalyzing extracellular proteolysis to prevent or circumvent protein precipitation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=329888Documentos Relacionados
- Urokinase-type plasminogen activator is effective in fibrin clearance in the absence of its receptor or tissue-type plasminogen activator.
- Origins of the specificity of tissue-type plasminogen activator.
- Tissue-type plasminogen activator increases the binding of glu-plasminogen to clots.
- Coronary Thrombolysis with Tissue-Type Plasminogen Activator: Prospective Review
- Expression of Active Human Tissue-Type Plasminogen Activator in Escherichia coli