The effect of preoperative 5-fluorouracil on colonic healing: An experimental study

WOS: 000172705600026PubMed ID: 11813589Background/Aims: After curative resection for colorectal carcinoma there is a high recurrence rate and neoadjuvant chemotherapy may be useful in some patients. Very little is known about the effect of preoperative 5-fluorouracil on the healing of colon anastomosis. The aim of this study was to evaluate the effect of 5-fluorouracil on colonic healing when the time interval between the last injection and operation was shortened to 24 hours. Methodology: Thirty-six male Wistar rats with a median weight of 185g (range: 165-200g) were divided into three groups: 1) control group (n=12); 2) sham group (n=12) which received saline intraperitoneally, and 3) study group (n=12) which received 5-fluorouracil intraperitoneally (20mg/kg(-1)). All injections were given intraperitoneally for 5 days and the last dose was injected 24 hours before operation. Results: The mortality rate (22.7%) and anastomotic complications (29.4%) were increased in the 5-fluorouracil group, compared with the control or saline groups (P <0.05). The anastomotic bursting pressure in rats having 5-fluorouracil treatment (27mm Hg) was significantly lower from both the control (55mm Hg) and saline (84mm Hg) groups on postoperative day 3 (P <0.05). Both myeloperoxidase and hydroxyproline contents were also significantly lower than the other groups (P <0.05). Conclusions: Colonic healing was impaired and mortality rate was increased when intraperitoneal 5-fluorouracil treatment was repeated until 24 hours before operation

The effects of estrogen and raloxifene treatment on antioxidant enzymes in brain and liver of ovarectomized female rats

WOS: 000183965300008PubMed ID: 12856805Recent studies documented that estrogen have antioxidant properties in-vitro, there are conflicting results on the effect of estrogen in vivo. We aimed to investigate the effects of estradiol and Raloxifene on the antioxidant enzyme [superoxide dismutase (SOD) and catalase (CAT)] activities and MDA levels in brain and liver homogenates of ovariectomized female rats. Twelve weeks after ovariectomy, female Sprague-Dawley rats (n = 26) were divided into three groups: (1) Ovariectomized placebo group (n = 6) was given physiologic saline. (2) Estrogen group (n = 10) was given Ethynyl estradiol, 0.1 mg/kg sc. (3) Raloxifene group (n = 10) was given raloxifene, 1 mg/kg sc during 8 weeks. Ten rats were used as naive controls without any treatment (Sham operated group, n = 10). Ovariectomy lead to an increase in the CAT activities in liver tissue samples compared to the sham group (p = 0.056, Mann-Whitney test). While estrogen treatment reversed to normal levels of CAT activities, raloxifene remained as ineffective. Superoxide dismutase activities and MDA levels in liver were remained unchanged in all groups. There was no significant change in the brain tissue SOD and CAT activities between the control, ovariectomy, estrogen treated, and raloxifen treated groups. We determined an increase in MDA levels in brain of ovariectomised rat (p = 0.02). While raloxifene treatment reversed to normal levels of MDA (p = 0.008), estrogen treatment failed. Our data showed that estrogen may play a role in regulation of CAT and SOD activities in liver due to its antioxidative effects. We can suggest that estrogen and raloxifene exert their antioxidative effects in brain rather than liver. Since Raloxifene's effect is more clear than estradiol, raloxifene may be suggested primarily for treatment and/or prevention of diseases which can be resulted from oxidative stress in postmenopausal women

The effects of a monoamine oxidase inhibitor; Deprenyl on rat liver and renal tissues in aging.

WOS: A1997XD3630040

MAO inhibitors and oxidant stress in aging brain tissue

WOS: 000079244100010PubMed ID: 10208295The process of aging presents itself with various alterations in physiological events. Among many theories, the free radical (FR) theory of aging which reflects the FR damage to cellular components is accepted as one of the most important theories. Recently, the increases in catecholamine metabolism in aging have also attracted attention, and monoamine oxidase (MAO), a key enzyme in this process has been extensively studied. The aim of this study was to assess the role of FR species via MAO, a possible source of FRs, in physiological aging by determining the lipid peroxidation products (LPP) (malondialdehyde, diene conjugates) and antioxidant enzyme levels (superoxide dismutase (SOD) and catalase (CAT) in young (3 months old, n=10) and aging (16-18 months old, n=10) rat brain tissues of Swiss male albino rats. In the second part of the study, the same parameters were determined after the acute administration of MAO inhibitors (deprenyl and pargyline, 25 mg/kg i.p.) to investigate whether these agents have any beneficial effects in reducing oxidant stress via inhibition of MAO. In old rat brains, MAO activities showed a significant increase (P=0.000) in addition to an insignificant increase in LPP, while SOD (P=0.007) and CAT activities showed a decrease with advancing age. After the acute administration of both deprenyl and pargyline, a significant decrease in the MAO activities of both young (P=0.0002 for each) and aging rats (P=0.0002 for deprenyl and P=0.0001 for pargyline) were observed. It was noted that deprenyl causes a significant increase in CAT activity (P<0.05) but a significant decrease in SOD activity (P<0.05) in young rats, while it causes only a significant increase in SOD activity in aging rats (P<0.05). Both deprenyl and pargyline cause a significant decrease in conjugated diene levels of aging rats (P<0.05). These results confirm the role of catecholamine oxidation and MAO activity as one of the causative factors in increased oxidant stress during aging. By reducing the oxidant stress observed in aging brain, MAO inhibitors, especially deprenyl, may contribute to the control of the aging process. (C) 1999 Elsevier Science B.V. All rights reserved

Link between catecholamine and nitric oxide metabolism

WOS: 000084920300010PubMed ID: 1063712

The effects of estrogen and raloxifene treatment on the antioxidant enzymes and nitrite-nitrate levels in brain cortex of ovariectomized rats

WOS: 000181076000011PubMed ID: 12581835Number of studies indicate that the female gonadal hormone estrogen protects women against several neurodegenerative diseases and cerebral ischemia via various mechanisms. The possible protective effects of estrogen are mediated mainly by three ways; the activation of steroid receptors and/or modulation of a neurotransmitter and/or direct antioxidative action. Therefore we aimed to investigate the effects of estradiol and raloxifene on levels of nitric oxide (NO) and antioxidant enzymes in brain cortex of ovariectomized female rats. Ten Sprague-Dawley rats were used as naive controls while 32 rats were ovariectomized at 120-140 days of age. Twelve weeks after ovariectomy: (1) Ovariectomized Placebo group (n = 11), was given physiologic saline. (2) Estrogen group (n = 10) was given Ethynyl estradiol, 0.1 mg/kg sc. (3) Raloxifene group (n = 10) was given raloxifene, 1 mg/kg sc. At the end of the treatment period (8 weeks), rats were decapitated and cortex samples were dissected. Results showed that ovariectomy caused a decrease in total nitrite-nitrate levels. The NO levels of both the estrogen and the raloxifene group were higher than the placebo group. Catalase activities did not show any significant difference between the groups, while superoxide dismutase (SOD) activities were elevated via ovariectomy. Estradiol and Raloxifene treatment had no statistically significant effect on SOD activity. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved