Tissue-type plasminogen activator in rat adrenal medulla.
Rat adrenal glands were stained immunocytochemically using antibodies against plasminogen activators of the tissue-type (t-PA) and urokinase-type (u-PA). A subpopulation of the cells in the adrenal medulla showed intense cytoplasmic t-PA immunoreactivity, while no u-PA immunoreactivity was detected in any adrenal cells. Fluorescence microscopy of adjacent sections demonstrated that the cells stained for t-PA contained noradrenaline. Analysis with a histochemical fibrin slide technique demonstrated a plasminogen-dependent fibrinolysis in the adrenal medulla. SDS-PAGE of adrenal gland extracts followed by zymography established the molecular weight of this plasminogen activator to be similar to that of rat t-PA. In addition SDS-PAGE followed by immunoblotting with anti-t-PA IgG of adrenal gland extracts revealed one band with an electrophoretic mobility indistinguishable from that found in the zymography. When tissue-sections and immunoblots were incubated with antibodies absorbed with highly purified t-PA no staining was found. In view of the previous finding of t-PA in growth hormone-containing cells of the pituitary gland, these findings substantiate that t-PA can be found in the intact normal organism outside endothelial cells, and further point to t-PA having a function in endocrine cells.
D000313:Adrenal Medulla / Q000032:analysis*; D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D007124:Immunoenzyme Techniques; D007158:Immunologic Techniques; D008297:Male; D008856:Microscopy, Fluorescence; D009638:Norepinephrine / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D010959:Tissue Plasminogen Activator / Q000032:analysis*
D010959:Tissue Plasminogen Activator; D009638:Norepinephrine