Pekka Uotila

Lipid Peroxidation and Antioxidants in Normal and Pre-eclamptic Pregnancies

Lipid peroxidation has been suggested as a pathogenetic factor of pre-eclampsia. In this study we measured lipid peroxidation products and the counteracting antioxidant functions in maternal serum and placental tissue in normal pregnancy and pre-eclampsia. Placentae and maternal serum from 15 normal and 15 pre-eclamptic pregnancies were collected. Lipid peroxidation was measured as peroxidation potential, thiobarbituric acid reacting substances (TBARS) and conjugated diene onuble bonds. The antioxidative capacity was measured as the activity of superoxide dismutase, glucose 6-phosphate-dehydrogenase, glutathione peroxidase and glutathione transferase and the concentration of placental vitamin E. Placental lipid peroxidation was higher in pre-eclampsia than in normal pregnancy, when measured by peroxidation potential and TBARS (P = 0.002 and P = 0.027, respectively). The activity of placental superoxide dismutase (P = 0.003) and glucose 6-phosphate-dehydrogenase (P = 0.019) was significantly lower in pre-eclampsia than in normal pregnancy. There were no significant differences in the activity of glutathione peroxidase, glutathione-S-transferase or vitamin E level between the study groups. The peroxyl radical trapping capacity (TRAP) was higher (P = 0.013) in the serum of pre-eclamptic than control patients. Lipid peroxidation is increased and the activity of antioxidant enzymes superoxide dismutase and glucose 6-phosphate-dehydrogenase are decreased in pre-eclamptic placenta. The TRAP is high in the serum of pre-eclamptic patients.

Increased expression of cyclooxygenase-2 and nitric oxide synthase-2 in human prostate cancer

Abstract Cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase-2 (NOS-2) each have an important role in angiogenesis. The expression of these genes was investigated in human prostate cancer by immunohistochemistry, the expression of COX-1 and COX-2 being confirmed by mRNA analysis. Prostate cancer specimens from 12 patients were compared to control prostates from 13 patients operated on for bladder carcinoma. The intensity of COX-2 and NOS-2 immunostaining was significantly stronger in prostate cancer cells than in the non-malignant glandular epithelium of the control prostates. COX-2 and NOS-2 were clearly also expressed in the lesions of prostatic intraepithelial neoplasia (PIN) in control prostates. COX-2 was detected in the muscle fibres of the hyperplastic stroma of some control prostates. No significant difference was detected in COX-1 expression between control and cancer prostates. These results indicate that the expression of COX-2 and NOS-2 is elevated in prostatic adenocarcinoma and in PIN.

Evening primrose oil in the treatment of atopic eczema: effect on clinical status, plasma phospholipid fatty acids and circulating blood prostaglandins

In a double‐blind trial patients with atopic eczema received either oral evening primrose oil (EPO) (n= 14) or placebo (n= 11) for 12 weeks. In the EPO group a statistically significant improvement was observed in the overall severity and grade of inflammation and in the percentage of the body surface involved by eczema as well as in dryness and itch. Patients in the placebo group showed a significant reduction in inflammation. The patients receiving EPO showed a significantly greater reduction in inflammation than those receiving placebo.

The role of cyclic AMP and oxygen intermediates in the inhibition of cellular immunity in cancer.

Cell-mediated immunity is often impaired in cancer. This may be partly due to increased amounts of prostaglandin E2 (PGE2) and histamine in the blood of cancer patients, since PGE2 and histamine possess inhibitory effects on cellular immunity. These effects are mediated by cyclic AMP (cAMP), which is increased in leukocytes by PGE2 through EP2 and by histamine through H2 receptors and also by epinephrine through β2-adrenergic receptors. Increased cAMP activates protein kinase A, which inhibits the formation of interleukin 2 (IL-2) in T cells. The formation of interferon y is concomitantly decreased, and cellular immunity is attenuated. In monocyte/macrophages the formation of IL-1β, IL-12 and tumor necrosis factor a is decreased by cAMP or through the increased formation of IL-10, which is up-regulated by cAMP. This attenuates cellular immunity. In monocytes histamine may decrease the formation of oxygen intermediates, which can induce apoptosis of natural killer cells and thus inhibit immunity. The superoxide anion is a potent inducer of the cyclooxygenase-2 enzyme, which is upregulated in colorectal cancer. Cyclooxygenase-2 catalyzes the formation of PGE2, e. g. in cancer cells. Thus the inhibition of cellular immunity in cancer may be at least partly mediated by cAMP and oxygen intermediates. This may offer new options for cancer immunotherapy.

Indomethacin inhibits arachidonic acid metabolism via lipoxygenase and cyclo-oxygenase in hamster isolated lungs.

14C-Arachidonic acid (AA, 66 nmol) was injected into the pulmonary circulation of isolated perfused hamster lungs. The metabolites were analysed from the nonrecirculating perfusion effluent, which was extracted with ethyl acetate first at pH 7.4 (to extract unmetabolized AA, metabolites of lipoxygenase and HHT) and then at pH 3.5 for prostaglandins and thromboxanes. When indomethacin was infused into the pulmonary circulation, the metabolism of AA was decreased dose dependently. The amounts of all metabolites were decreased rather similarly by indomethacin. The present study indicates that indomethacin inhibits arachidonate metabolism via cyclo-oxygenase and lipoxygenase in hamster isolated lungs.

Expression of cyclooxygenase-1 and -2 in urinary bladder carcinomas in vivo and in vitro and prostaglandin E2 synthesis in cultured bladder cancer cells

Summary Cyclooxygenases (Coxs) are the rate‐limiting enzymes catalysing the formation of prostaglandins, which are involved in various of physiological processes. Increased Cox‐2 expression has been observed in several malignancies, but the exact role of Cox‐2 in carcinogenesis remains unsolved. We studied the expression of both Cox1 and Cox‐2 by immunohistochemistry in 29 transitional cell carcinomas of the urinary bladder. Diffuse cytoplasmic immunosignal for Cox‐2 was detected in all cancer specimens. The expression was moderate in 55% and strong in 31% of the carcinomas. The normal urothelium in the samples stained also for Cox‐2, but the intensity of the immunosignal was weak in most specimens. Cox‐1 was expressed in the stroma of bladder wall, whereas in the tumour cells, Cox‐1 immunosignal was either absent or weak. No correlation was detected between Cox‐1 or Cox2 expression and tumour differentiation or stage of invasion. We also evaluated the mRNA expression of Cox1 and Cox‐2 and synthesis of prostaglandin E 2 (PGE 2 ) in three bladder carcinoma cell lines (RT4, 5637, and T24). All cell lines expressed high levels of Cox‐2 mRNA, whereas Cox‐1 mRNA expression was detected only in T24 cells. There was great variation in the basal levels of PGE 2 synthesis in these cell lines. Indomethacin inhibited the synthesis of PGE 2 in all three cell lines, although the level of Cox‐2 mRNA tended to increase by indomethacin. These results indicate that Cox‐2 is widely expressed in human bladder carcinomas and that the role of Cox‐2 inhibition in bladder cancer should be further studied.

Metabolism of testosterone in the isolated perfused rat lungs

Abstract The metabolism of [4-14C]-testosterone in the isolated perfused rat lungs was investigated following the administration of the substrate eithervia the pulmonary artery orvia the trachea. After administration of testosterone in the circulating medium, 3.5% of the hormone was metabolized to various unconjugated metabolites during a single passage through the pulmonary circulation. It so seems that the lungs, receiving all the cardiac output, are one of the major sites of androgen catabolism in the rat organism. The major metabolites were 5α- and 5β-androstane-3α,17β-diols and various non-conjugated polar metabolites. After intratracheal instillation, testosterone was rapidly absorbed from rat lungs. Two minutes following installation, 62% of the dose was recovered from the lungs. Two thirds of this was present as metabolites. It is concluded that the lungs have an efficient metabolic capacity towards androgens. The availability of extractable substrate seems to be rate limiting for the pulmonary testosterone metabolism.

The expression of cyclooxygenase-1 and -2 in proliferative endometrium and endometrial adenocarcinoma

BACKGROUND. The activity of cyclooxygenase-2 (COX-2) is increased in inflammation and in several cancer types. We investigated the expression of COX-2, cyclooxygenase-1 (COX-1), nitric oxide synthase-2 (NOS-2) and nitric oxide synthase-3 (NOS-3) in normal proliferative and secretory human endometrium, and in endometrial adenocarcinoma. METHODS. Human endometrium was collected at hysterectomy. Seven samples were in proliferative and 11 samples in secretory stage. Twelve specimens from endometrial carcinoma were collected, as well. Immunohistochemistry was used to investigate the expression of COX-1, COX-2, NOS-2 and NOS-3. RESULTS. COX-2 immunostaining was detected in most specimens of normal proliferative glandular epithelium (86%) and of endometrial carcinomas (92%). COX-2 staining was often detected in cancer cells on the border areas of the tumour and on the areas of invasive growth. Staining for COX-2 was seen in proliferative glands usually only in the basal layer of the endometrium. NOS-2 was usually absent or negligible in proliferative endometrial glands and also in the cancer cells of endometrial adenocarcinomas. No staining for either COX-2 or NOS-2 was seen in specimens of secretory glandular epithelium. The expression of the constitutive COX-1 and NOS-3 was negligible or weak in the glandular epithelium of proliferative and secretory endometrium and in endometrial cancer cells. CONCLUSIONS. The expression of the inducible COX-2 but not of COX-1 is stimulated in the glandular epithelium of proliferative endometrium and in the cancer cells of human endometrial adenocarcinoma, in particular in those in the borders of carcinoma and spreading into lymphatic vessels.

The effect of vitamin C and E on placental lipid peroxidation and antioxidative enzymes in perfused placenta

BACKGROUND To investigate placental lipid peroxidation products and antioxidative enzymes after vitamin C and/or E infusions into the maternal circulation of normal and preeclamptic placentas perfused in vitro. METHODS Placentas from 29 normal and six preeclamptic women delivered between 27 and 41 weeks of gestation were used in the study. RESULTS Neither vitamin C (500 microM) nor vitamin E (50 microM) had any effect on placental lipid peroxidation or antioxidative enzymes in normal placentas. Vitamin C infused in preeclamptic placentas decreased peroxidation potential, as an indicator of lipid peroxidation to the same level it was in normal placentas (812 vs. 649 mV/mgprot; p=0.420). The activity of superoxide dismutase (SOD) was lower (1350 vs. 2030 ng/mgprot; p=0.023) in preeclamptic placentas, and the activities of glutathione peroxidase (0.22 vs. 0.08 micromol/min x mgprot; p=0.010) and glutathione-S-transferase (19.8 vs. 13.1 micromol/min x mgprot; p=0.016) were higher in preeclamptic compared to normal placentas. CONCLUSION In this study, based on in vitro perfused normal and preeclamptic placentas, exogenous antioxidative vitamins had no effect on lipid peroxidation or endogenous antioxidative enzymes in normal placenta, but reduced placental lipid peroxidation and could potentiate the activity of some endogenous placental antioxidative enzymes in preeclamptic placenta.

Interferon-α inhibits cyclooxygenase-1 and stimulates cyclooxygenase-2 expression in bladder cancer cells in vitro

Abstract The enzymes cyclooxygenase-1 (Cox-1) and cyclooxygenase-2 (Cox-2) catalyze the initial step in the formation of prostaglandins (PGs). PGs are known to be involved in numerous processes, for example inflammation, immune responses, carcinogenesis, and tumor angiogenesis. The formation of PGs is stimulated in various cancers since the expression of Cox-2 is upregulated. Interferon (IFN)-α is used in the treatment of bladder cancer, although not all of the effects of such treatment are thoroughly known. Therefore, we investigated the expression of cyclooxygenases in two bladder cancer cell lines, 5637 and T24, under basal conditions and in the presence of human recombinant IFN-α (100, 1,000, and 10,000 U/ml). The mRNA of Cox-1 and Cox-2 was expressed in both cultured bladder carcinoma cell lines. The level of Cox-1 expression was low in 5637 cells and higher in T24 cells. In contrast, Cox-2 expression was prominent in 5637 cells and low in T24 cancer cells. The highest IFN-α concentration (10,000 U/ml) decreased the expression of Cox-1 to 47 and 28% of the control levels in 5637 and T24 cells, respectively. In contrast, Cox-2 expression increased in both cell lines. In 5,637 cells, Cox-2 expression increased 1.3-fold with 10,000 U/ml of IFN-α. In T24 cells, the maximum effect was achieved by 1,000 U/ml of IFN-α, which increased the expression of Cox-2 up to 2.4-fold. These findings may have relevance in the outcome of patients treated with IFN-α because upregulated Cox-2 expression may suppress the cell-mediated defense system. On the other hand, the inhibition of Cox-1 could be beneficial because Cox-1 is known to stimulate angiogenesis.