Effects of hormone replacement therapy on plasma pro-inflammatory and anti-inflammatory cytokines and some bone turnover markers in postmenopausal women.

OBJECTIVE: The present study was undertaken to evaluate plasma TNFalpha, IL-1beta, IL-10; and urinary hydroxyproline (Hyp) and calcium (Ca) as bone resorption markers in postmenopausal women compared with premenopausal ones; and to assess the effects of HRT upon these cytokines and bone turnover markers. PATIENTS AND METHODS: The study involved 50 healthy postmenopausal women, and 25 healthy premenopausal women (control group). Postmenopausal women were randomly divided into two subgroups: women receiving cycle HRT schedule (0.625 mg conjugated estrogen from days 1 to 28+5 mg medroxyprogesterone acetate from days 18 to 28) for 2 months (n=25); and second subgroup consisted of women receiving continue HRT schedule (0.625 mg conjugated estrogen+2.5 mg medroxyprogesterone acetate from days 1 to 28) for 2 months (n=25). Plasma TNFalpha, IL-1beta and IL-10 concentrations were measured with ELISA kits. Fasting urinary Hyp was measured by Ehrlich's spectrophotometric reaction. Ca was determined by oxalate precipitation and the redox titration procedure. Statistical significance was analysed by Kruskal-Wallis plus post hoc Mann-Whitney U-tests for multiple comparisons, Wilcoxon signed ranks test for paired data, and Pearson correlation test. RESULTS: Compared with premenopausal individuals, postmenopausal women have increased plasma TNFalpha, IL-1beta, IL-10 (p<0.0001, p<0.0001, and p<0.001, respectively); and increased urinary Hyp and Ca concentrations (p<0.05). HRT (both cycle and continue schedules) lead to a significant decrease in TNFalpha, IL-1beta and urinary Hyp concentrations, and has no effect uppon IL-10 levels. HRT reverses increased urinary Hyp and Ca excretion to the premenopausal level. There is a significant positive correlation between pre- and post-HRT IL-1beta levels in both cycle and continue subgroups (r=0.437, p<0.05; and r=0.656, p<0.01, respectively), and between pre-HRT IL-1beta and urinary Ca (r=0.509, p<0.01; and r=0.415, p<0.05). There is a significant negative correlation between post-HRT IL-10 and TNFalpha levels in continue HRT receiving group (r=-0.446, p<0.05). Urinary Hyp in cycle and continue HRT received subgroups are correlated with post-treatment values (r=0.455, p<0.05; and r=0.776, p<0.01). CONCLUSIONS: Plasma TNFalpha, IL-1beta, IL-10; and urinary Hyp and Ca increase with menopause. We suggest that the increase of IL-10 is secondary to the elevation of TNFalpha and IL-1beta and that the increase of IL-10 is a compensatory mechanism, by which this anti-inflammatory cytokine counteracts to pro-inflammatory TNFalpha and IL-1beta, and thus balances their osteoclast activating and oxidative stress-related effects. Two months duration HRT (cycle and continue schedule) lead to the significant decrease in plasma TNFalpha, IL-1beta and urinary Hyp concentrations. HRT reverses increased Hyp and Ca excretion to the premenopausal level. So, HRT, decreasing Th1 cytokines (TNFalpha, IL-1beta) probably improve the aberation of Th1/Th2 balance that is implicated in various pathological conditions. However, because of the relatively small number of participants and short duration of the therapy, further studies are necessary to establish a risk/benefit ratio for HRT to view effects on cytokine pattern and bone metabolism.

Effects of menopause and postmenopausal tibolone treatment on plasma TNFalpha, IL-4, IL-10, IL-12 cytokine pattern and some bone turnover markers.

OBJECTIVE: To asses plasma TNFalpha, IL-4, IL-10, IL-12; urinary hydroxyproline (Hyp) and calcium as bone resorption markers in healthy postmenopausal women compared with premenopausal ones, and to observe the effect of tibolone (2.5mg/day for 6 months) upon above mentioned parameters. PATIENTS AND METHODS: The study involved 24 healthy postmenopausal women (study group) and 25 premenopausal women (control group). Plasma TNFalpha, IL-4, IL-10 and IL-12 concentrations were measured using ELISA kits. Fasting urinary Hyp was measured by Ehrlich's spectrophotometric reaction. Calcium was determined by oxalate precipitation and the redox titration procedure. Statistical significance was analysed by the Mann-Whitney U-test for unpaired data, Wilcoxon Signed Rank test for paired data, and Pearson correlation test. RESULTS: Postmenopausal women (both before and after tibolone treatment) have increased (p<0.001) plasma TNFalpha, IL-4, IL-10, IL-12; and increased urinary Hyp (p<0.05) and calcium (p<0.001) concentrations in comparison with premenopausal individuals. Tibolone treatment has no effect on reversing the increased postmenopausal plasma TNFalpha, IL-4, IL-10 and IL-12, but decreases urinary Hyp and calcium to premenopausal levels. There is a weak positive correlation (r=0.532; p<0.05) between TNFalpha and IL-4 levels in postmenopausal women. CONCLUSIONS: The results show that plasma TNFalpha, IL-4, IL-10, IL-12, urinary Hyp and calcium increase with menopause. The increase of anti-inflammatory IL-10, IL-12 and especially IL-4 is probably a compensatory mechanism, by which these cytokines counteract to pro-inflammatory TNFalpha, and thus balance its osteoclast activating and oxidative stress inducing effects. Tibolone is successful in decreasing of bone resorption markers (urinary Hyp and calcium), but has no effect on reversing the impact of menopause on plasma TNFalpha, as well as IL-4, IL-10, IL-12. The last effect probably is related with progestogenic and androgenic properties of tibolone. Clearly, further studies are necessary to establish a risk/benefit ratio for tibolone in view of its effects on bone turnover as a new hormone replacement rationale.

Plasma nitrate/nitrite and endothelin-1 in patients with liver cirrhosis.

The aims of this study were to examine the plasma nitrate/nitrite (NOx; two end products of nitric oxide metabolism) and endothelin-1 (ET-1) concentrations in patients with liver cirrhosis, and to investigate whether there is a relationship between these two vasoactive parameters and the course of disease. Twenty-eight patients with liver cirrhosis (11 HBV-related, four HCV-related, four alcohol-related, and nine with idiopathic etiology) and 25 healthy subjects (controls) were included in the study. The venous plasma concentrations of NOx and ET-1 were significantly higher (P<0.01 and P<0.001) in the patients with cirrhosis than in the controls. A significant increase in ET-1 was observed in the Child B subgroup vs. Child A (P<0.05), and in the Child C subgroup vs. either subgroup A or B (P<0.05). There were no statistical differences between study subgroups (Child A-C) in the mean of NOx values. Plasma NOx and ET-1 were significantly increased in patients with ascites compared to those without ascites (P<0.05 and P<0.01). Increased nitric oxide synthesis may be a compensation mechanism against endothelial injury. The highest ET-1 levels in Child C and moderately increased ET-1 levels in Child B, and the lower increase of ET-1 levels in Child A patients suggest that plasma ET-1 increases with the progression of the disease. The fact that NOx and ET-1 levels were higher in patients with decompensated cirrhosis (patients with ascites) than in those with compensated cirrhosis (patients without ascites), and the presence of a strong correlation between ET-1, NOx, and the degree of varices, supports the suggestion that there is a relationship between NOx, ET-1, and portal hypertension. Our study demonstrates that increased ET and nitric oxide metabolism is associated with the hemodynamic alterations induced by portal hypertension.

Ibuprofen reduces plasma nitrite/nitrate levels in a rabbit model of endotoxin-induced shock.

OBJECTIVES: The purpose of this study was to investigate the effects of ibuprofen on plasma nitrite/nitrate levels, as indirect indicators of nitric oxide, in correlation with blood pressure in a rabbit model of endotoxin-induced shock. METHODS: A total of 28 rabbits were randomly divided into four groups. Control group received physiological saline, while endotoxin (ETX, E. Coli, 055:B5, 2 mg/kg, i.v.) was administered to the rabbits in the other groups: group II receiving only ETX, in addition to ETX group III received ibuprofen (30 mg/kg) 30 minutes after ETX administration, whilst the group IV received ibuprofen (30 mg/kg) 30 minutes before ETX. Arterial blood pressure and plasma levels of nitrite/nitrate were determined immediately before (time 0) and 30, 60, 90, 120, 180, 240, and 300 minutes after ETX administration. RESULTS: ETX administered groups had significantly higher plasma levels of nitrite/nitrate than the control group, at all consecutive measurements except at time O. Treatment with ibuprofen, either before or after ETX, partly restored the elevated levels of nitrite/nitrate. ETX also caused a significant decrease in blood pressure which was prevented in ibuprofen treated groups. CONCLUSION: Results from this study indicate that administration of ibuprofen prevents sudden reductions in blood pressure by inhibiting excessive production of nitric oxide in rabbit model of endotoxin-induced shock and this may be of importance for providing crucial time for therapeutic intervention and survival in septic shock.

Effects of menopause and tibolone on antioxidants in postmenopausal women.

BACKGROUND: Oxidative stress has been implicated in the pathogenesis of ageing and menopause, and can arise through the increased production of lipid peroxides and/or a deficiency of antioxidant defence. AIM: To investigate the effects of the menopause and tibolone treatment (2.5 mg/day for six months) on plasma antioxidants and lipid peroxidation. METHODS: Plasma concentrations of ascorbic acid, alpha-tocopherol, total thiol groups, caeruloplasmin, erythrocyte glutathione (GSH) and malondialdehyde (MDA) were measured in 24 postmenopausal and 24 premenopausal healthy women. RESULTS: Data analysis indicates a significant decrease in plasma ascorbic acid, alpha-tocopherol, total thiol groups, [corrected]erythrocyte GSH and a significant increase in lipid peroxides (expressed as MDA concentrations) in postmenopausal women. There was no significant difference between control and study groups in the mean plasma caeruloplasmin concentrations. It was found that there is a significant increase in alpha-tocopherol and significant decrease in lipid peroxide concentrations in postmenopausal after tibolone treatment. CONCLUSIONS: The menopause is associated with an increase in oxidative stress and a decrease of some antioxidants, such as ascorbic acid, alpha-tocopherol, total thiols and erythrocyte GSH. Tibolone treatment leads to a decrease in concentrations of plasma lipid peroxide, probably by stimulating direct and indirect mechanisms of tocopherol regeneration and increasing plasma concentrations of vitamin E. However, due to the relatively small numbers involved this study can be regarded as a pilot. Further studies performed on a larger scale are necessary to establish the exact mechanisms of tibolone in inhibiting oxidative stress in postmenopausal women.

Synovial fluid nitric oxide levels in patients with knee osteoarthritis.

Nitric oxide (NO) has an important role in the inflammatory arthropathies. This study investigated NO levels in the synovial fluid and plasma of patients with primary osteoarthritis (OA) of the knee. Twenty-seven cases with primary knee OA and 13 controls were recruited for the study. Nitrate/nitrite levels of synovial fluid and plasma were measured by Griess reaction, and interleukin-1 beta (IL-1 beta) levels were measured quantitatively by a sandwich immunoassay technique. We found a significant increase in the synovial fluid nitrate/nitrite levels in cases with primary OA of the knee compared to controls (50.26+/-23.63 microg/l vs 32.49+/-10.05 microg/l, p=0.002) as well as increased plasma nitrate/nitrite levels (57.06+/-23.32 microg/l vs 39.98+/-16.36 microg/l, p=0.012). There was no difference in plasma and synovial fluid IL-1 beta concentrations between the study and control groups. These results may be considered as supporting evidence that NO might be one of the factors responsible for cartilage destruction in primary osteoarthritis of the knee.

Effects of ibuprofen on the physiology and outcome of rabbit endotoxic shock.

BACKGROUND: Despite major developments in the management of septic shock, the mortality rate had progressively increased. Ibuprofen has been shown to have beneficial physiological effects when used as a treatment. However, there are conflicting results with respect to survival. This study aims to investigate the effect of ibuprofen on vital functions, various physiological parameters and survival during endotoxic shock in rabbits. METHODS: Twenty-eight New Zealand rabbits were randomly separated into four groups. The first group received only saline, the second was given 2 mg/kg intravenous endotoxin at t0, the third received 30 mg/kg ibuprofen 30 minutes after endotoxin administration, whilst the fourth group received ibuprofen 30 minutes before the endotoxin. Respiratory and heart rate, mean arterial blood pressure and rectal temperature were recorded. Complete blood counts were performed and thromboxane B2 was measured every 30 minutes for the first two hours, and then hourly over the course of the experiment. Urine samples were collected at the same time points for the measurement of prostaglandin E2. RESULTS: Ibuprofen was found to improve respiratory rate, heart rate, and arterial pressure. However, it did not improve the negative effects of endotoxin on body temperature, haematocrit values, white blood cell count, and thrombocyte number. Thromboxane B2 levels in group IV were significantly lower than in the other groups, and the increase started at a later timepoint. In ibuprofen-treated animals, Prostaglandin E2 levels stayed low for at least 90 minutes, but started to rise thereafter. While the average survival in Group II animals was 192.9 +/- 46.9 minutes, those of groups III and IV were 339.1 +/- 33.5 minutes (p < 0.05) and 383.0 +/- 39.6 minutes (p = 0.01), respectively. CONCLUSIONS: Ibuprofen appears to increase survival in endotoxic shock-induced animals. Therefore, it may be helpful for the prophylaxis and treatment of patients with, or who are likely to develop, septic shock.

Effects of diabetes mellitus and acute hypertension on plasma nitric oxide and endothelin concentrations in rats.

AIM: To examine the plasma nitrate/nitrite (NOx-two end products of the nitric oxide metabolism) and endothelin (ET) concentrations, and response to acute adrenaline induced hypertension in diabetic rats. MATERIALS AND METHODS: Four groups of 4-month-old rats were used: control rats (C, n=10) rats received adrenaline (A, 40 microg/kg i.v., n=10), rats received streptozotocin (S, 50 mg/kg i.v., n=8), and rats received STZ and adrenaline (SA, n=9). The experiments were performed 4 weeks after the STZ administration. Plasma NOx, ET, glucose, and mean arterial blood pressure (MAP) were measured. RESULTS: Plasma ET concentrations were significantly increased in diabetic rats (S and SA) in comparison with the controls and adrenaline-only administered rats. NOx concentrations in diabetic groups (S and SA) were significantly decreased in comparison with the controls. Acute adrenaline induced hypertension in diabetes leads to a significant decrease of NOx concentrations in comparison with the controls, adrenaline-only administered and STZ-only administered rats. There was no difference between the MAP in diabetic and control rats. Adrenaline injection caused a significant increase of MAP in A and SA groups. Plasma glucose concentrations in diabetic rats (S and SA) were significantly increased in comparison with the nondiabetic groups (C and A). There was a weak but significant correlation between the NOx and ET concentrations in the controls, which probably reveal the balance between these vasoactive factors. In A, S, and SA groups, no significant correlation between the NOx/ET was found. CONCLUSION: An impairment of the NOx and ET formation could be involved in the pathogenesis of diabetes mellitus and especially acute hypertension and diabetes. A lack of correlation between the NOx and ET probably indicated that in diabetes and acute hypertension, a primary mechanism of compensatory nitric oxide might be lost.

Effects of tibolone on endogenous nitric oxide (nitrite/nitrate levels) in postmenopausal women.

OBJECTIVE: To observe the effects of hormone replacement therapy with 2.5 mg/day tibolone for 6 months upon plasma nitrite/nitrate (end products of nitric oxide metabolism) in postmenopausal women. PATIENTS AND METHODS: The study involved 24 healthy postmenopausal women treated with tibolone (2.5 mg/day for 6 months) and 20 postmenopausal women who received placebo. Plasma nitrite/nitrate levels were measured with the Griess reaction. Statistical significance was analyzed by the Mann-Whitney U test and Pearson correlation analysis. RESULTS: The mean baseline concentrations of nitrite/nitrate were similar in both treated and placebo groups. Tibolone treatment decreased plasma nitrite/nitrate levels. CONCLUSIONS: We suggest that because of its androgenic and progestogenic actions, tibolone diminishes nitrite/nitrate levels. Also our data provide evidence for the existence of increased (1/3 of subjects, n = 8) and reduced (2/3 of subjects, n = 16) nitrite/nitrate levels in response to tibolone treatment. Clearly, further studies are necessary to establish a risk/benefit ratio for tibolone in view of its effects on nitric oxide metabolism.

Effects of tibolone on thromboxane B(2) levels in postmenopausal women.

This study was carried out in 16 premenopausal (control) and 24 postmenopausal women (study group) to investigate the effect of menopause and tibolone treatment (2.5 mg/day for 6 months) on plasma thromboxane B(2) (TxB(2)), a well-known vasoconstrictor and stimulator of platelet aggregation. The TxB(2) levels were measured using [(125)I] RIA kit. Statistical significance was analyzed by Student's t test for paired and unpaired data, and Pearson's correlation analysis. Plasma TxB(2) concentrations of postmenopausal women were higher than those of premenopausal women. Tibolone treatment decreased plasma TxB(2) in postmenopausal women. There was no correlation between TxB(2) and blood pressure and heart rate. It was concluded that tibolone, decreasing the plasma concentrations of TxB(2), might have beneficial effects on prostaglandin metabolism and thus reduce the risk of cardiovascular disease.

Effects of ibuprofen on plasma endothelin levels and some vital parameters during endotoxin shock in rabbits.

BACKGROUND: There is evidence that septic shock results from breakdown in the balance between vasodilators such as prostacyclin, prostaglandin E(2), and nitric oxide, and the vasoconstrictors thromboxane A(2), serotonin, and endothelin. Increased plasma endothelin (ET) concentrations during septic shock were found. Inducing phospholipase A(2), ET causes release of arachidonic acid and production of prostaglandins. Ibuprofen is nonsteroidal anti-inflammatory drug inhibiting prostaglandin synthesis. There are no any information about the effects of ibuprofen on ET production in endotoxemia. In the present study we aimed to determine the effects of ibuprofen on plasma ET concentrations in an animal model of endotoxin shock. METHODS: A total of 28 rabbits were randomly allocated into four groups. The first group only received saline and served as controls. The rest of the animals (groups 2, 3, and 4) were injected intravenously with endotoxin at a dose of 2 mg/kg. To the third group, ibuprofen at 30 mg/kg dosage was given, 30 min following endotoxin administration, whereas in the fourth group animals, ibuprofen was administered 30 min before endotoxin administration. Animals were monitored through the canulation of femoral arteries and venules under the complete anaesthesia. At 0, 30, 60, 90, 120, 180, and 240 min, arterial blood pressure, heart rate, and ET determinations were carried out. RESULTS: Ibuprofen before the endotoxin administration was more effective in controlling the increase in heart rate. Ibuprofen was also effective in inhibiting the sudden reductions in blood pressure if administered before endotoxin. However, if administered after endotoxin injection, ibuprofen precipitated the reduction in blood pressure further. Ibuprofen reduced the ET production which was induced by the endotoxin administration. CONCLUSIONS: Ibuprofen administration during endotoxin shock seems to decrease the elevated ET concentrations, and increase the blood pressure.

El óxido nítrico y la endotelina-1,2 en queratosisactínica y carcinoma de células basales:cambios en el cociente óxido nítrico/endotelina / Nitric oxide and endothelin-1,2 in actinic keratosis and basal cell carcinoma: changes in nitric oxide/endothelin ratio

Antecedentes: El óxido nítrico (ON) es un gas inorgánico con un radical libre que desempeña acciones citostáticas/citotóxicas sobre tejidos tumorales, como cánceres ginecológicos, de mama y de colon. El óxido nítrico actúa también como una molécula activa productora de señales multifuncionales en muchas células del cuerpo, como células endoteliales, macrófagos, monocitos, hepatocitos, mastocitos, y astrocitos. La endotelina-1 (ET-1) es un péptido compuesto de 21 aminoácidos que estimula la proliferación de las células del músculo liso vascular, fibroblastos y queratinocitos y desempeña un papel importante en la expresión de los protooncogenes (c-myc,c-fos) que preceden a la proliferación celular. Igual que el ON, la ET se secreta por diferentes por diferentes tipos de células, como macrófagos, monocitos, hepatocitos, células endoteliales, células del músculo liso vascular y varias células tumorales. Se observan valores elevados de ET-1 en cánceres pulmonares, de células hepáticas y de próstata. La queratosis actínica (QA) y el carcinoma de células basales (CCB) son tumores de piel frecuentes con hiperqueratinización, hiperpigmentación y proliferación de queratinocitos acentuadas. Objetivo: Investigar la concentración en plasma de ONx (nitritos/nitratos -productos finales del metabolismo de ON), ET, y el valor del cociente ONx/ET en pacientes con QA y GCB en comparación con controles sanos. Métodos: Se midieron ONx, ET y el cociente ONx/ET en 13 pacientes con QA, en 12 pacientes con CCB y en 16 controles sanos. Resultados: Los análisis de los datos indican un aumento significativo de las concentraciones en plasma de ONx, ET, y del cociente ONx/ET en pacientes con CCB respecto a los controles (p<0,001, p<0,005 y p<0,001, respectivamente). Las concentraciones plasmáticas de ET en la QA también aumentaron en comparación con los controles (p<0,001). Cuando se compararon los dos grupos del estudio (QA y CCB), se encontró un aumento significativo (p<0,001) en el cociente ONx/ET en CCB. Conclusiones: El aumento de las concentraciones en plasma de ET y ONx en QA y especialmente en CCB son probablemente el resultado y/o la razón de la hiperqueratinización, hiperpigmentación y proliferación de queratinocitos acentuadas. La mayor producción de ET y ON por los queratinocitos puede actuar como factor de crecimiento y citotóxico y potenciar los mitógenos, lo que puede acelerar aun más la proliferación de estos tumores de piel. Además, el aumento del cociente ONx/ET probablemente refleja la alteración del equilibrio entre estas dos sustancias, lo que origina daño celular y desarrollo y proliferación tumorales (AU)