In this study, the effect of phorbol ester on the synthesis of nitric oxide(NO) in murine microglial cells was examined. Phorbol 12-myristate 13-acetate(PMA), a protein kinase C(PKC) activator, alone had no effect, whereas PMA with recombinant interferon-gamma(rIFN-gamma) synergistically increased NO synthesis in murine microglial cells. The maximal effect of PMA in the increase of NO synthesis always fit with the range for rull activation of PKC in these cells. The increase of NO synthesis was reflected as increased amount of inducible NO synthase(iNOS) mRNA by Northern blotting. Treatment of PKC inhibitors such as staurosporine(STSN) or polymxin B decreased rIFN-gamma plus PMA-stimulated NO synthesis. Further, prolonged incubation of the cells with PMA, which down regulate PKC activity, abolished synergistic cooperative effect with IFN-gamma. N(G)-monomethyl-L arginine monohydrate(NGMMA), an analogue of L-arginine, and arginase inhibited rIFN-gamma plus PMA-induced NO production in murine microglial cells. On the basis of these observations we conclude that PKC might not be involved in the expression of iNOS, but instead, might be involved in the post-transcriptional modification of iNOS mRNA.
Arginase ; Arginine ; Astrocytes ; Blotting, Northern ; Microglia ; Myristic Acid* ; Nitric Oxide Synthase Type II ; Nitric Oxide* ; Protein Kinase C ; Protein Kinases ; RNA, Messenger

Renal thromboembolism almost always occurs in the setting of cardiac disease. Acute renal infarction may occur rarely in middle-aged patients without apparent risk factors for cardiac thromboembolism. We report a 40-year-old man who developed bilateral renal infarction and had no cardiovascular risk factors, except smoking. In middle-aged healthy patients with renal colic without lithiasis, the diagnosis of idiopathic renal infarction should be considered, especially if lactate dehydrogenase is elevated.
Adult ; Heart Diseases ; Humans ; Infarction ; Kidney ; L-Lactate Dehydrogenase ; Lithiasis ; Renal Colic ; Risk Factors ; Smoke ; Smoking ; Thromboembolism