Inhibition of tumour growth by lipoxygenase inhibitors

Modulation of guanylate cyclase by lipoxygenase inhibitors.

Drugs that inhibit endothelium-dependent relaxation were tested to determine their effect on soluble guanylate cyclase purified from dog aorta. Basal, arachidonic acid (10(-5) M)-stimulated, and nitroprusside (5 X 10(-5) M)-stimulated guanylate cyclase activities were inhibited by methylene blue and the lipoxygenase inhibitors nordihydroguaiaretic acid and eicosatetraynoic acid. The effective i...

Nonredox 5-lipoxygenase inhibitors require glutathione peroxidase for efficient inhibition of 5-lipoxygenase activity.

Nonredox type 5-lipoxygenase (5-LO) inhibitors, such as ZM 230487, its methyl analogue ZD 2138, or the Merck compound L-739,010, suppress cellular leukotriene synthesis of ionophore stimulated granulocytes with IC50 values of about 50 nM. However, in cell homogenates or in preparations of purified enzyme, up to 150-fold higher concentrations are required for similar inhibition of 5-LO activity....

Inhibition of teleocidin-caused epidermal ornithine decarboxylase induction by phospholipase A2-, cyclooxygenase- and lipoxygenase-inhibitors.

Teleocidin (5 micrograms/mouse), a potent tumor promoting indole alkaloid from Streptomyces, induced epidermal ornithine decarboxylase (ODC) in CD-1 mice. Teleocidin-caused ODC induction was inhibited by the treatment of indomethacin (2 mumol/mouse), a selective cyclooxygenase inhibitor, and p-bromophenacyl bromide (BPB) (30 mumol/mouse), a phospholipase A2 inhibitor. Teleocidin-caused ODC indu...

REOVIRUS GROWTH INHIBITION BY ROTAVIRUS FOLLOWING COINFECTION

Selective inhibition of growth of transformed cells by protease inhibitors.

Five protease inhibitors with different modes of action were found to reduce the growth of transformed mouse (Py3T3, SV3T3, and 3T12) and hamster (PyBHK) cells. Some of these inhibitors caused the transformed cells to cease growth at saturation densities characteristic for nontransformed cells. The protease inhibitors were strikingly selective with regard to the transformed cells; they had esse...