Sibel Dinçer

Relationships between tensile strength, ascorbic acid, hydroxyproline, and zinc levels of rabbit full-thickness incision wound healing.

PurposeThis work was carried out to follow up the healing of full-thickness incision wounds opened on the back skin of rabbits in order to gain insight into the periodical correlation among such factors as ascorbic acid, collagen (hydroxyproline), the zinc content, and tensile strength of wound tissue. The need to provide vitamin C or zinc supplements after such wound incisions is also discussed.MethodsFull-thickness incision wounds and the ascorbic acid and hydroxyproline levels were measured in 24 rabbits by spectrophotometric methods on day 0 and on the 3rd, 5th, 7th, and 15th days after operation. The tensile strength was measured by a polygraph using a force displacement transducer. The zinc levels of the wounds were measured by atomic absorption spectrophotometry.ResultsThe zinc and hydroxyproline levels reached the peak levels on the 5th day, but the tensile strength of wound increased sharply on the 7th day after wounding while the zinc levels did not change. These results indicated that in the first 7 days of wound healing, high levels of ascorbic acid, hydroxyproline, and zinc cumulation occurred in the wound tissue, and the tensile strength reached its highest level on the 15th day without any supplementation.ConclusionThe supplementation of zinc and/or ascorbic acid should therefore be given just at the beginning of the wounding period, especially if there is deficiency of these nutrients.

The protective effect of taurine pretreatment on carbon tetrachloride-induced hepatic damage – A light and electron microscopic study

Summary. The results regarding taurine pretreatment on CCl4-induced hepatic injury are controversial. To assess the therapeutic efficacy of taurine on rat liver injury, hepatic malondialdehyde, glutathione, and hydroxyproline levels together with morphologic alterations in the liver following CCl4 administration were investigated. The rats were divided into three groups. Taurine-treated animals received 15 ml/kg/day of a 5% taurine solution by a gastric tube for 5 days before administering CCl4 (2 ml/kg, intraperitoneally, in a single dose). CCl4-treated rats received the same amount of saline solution. Control animals received no treatment. The increase of hepatic malondialdehyde formation in the CCl4-treated group was partially prevented by taurine pretreatment, but taurine had no significant effect on the glutathione and hydroxyproline content in the CCl4-treated rats. Taurine pretreatment induced a marked beneficial effect regarding the prevention of hepatocellular necrosis and atrophy as demonstrated morphologically. In conclusion, these results suggest that taurine pretreatment might not significantly change the biochemical parameters, but prevents the morphologic damage caused by CCl4 in the early stages.

The effect of EGF application in gel form on histamine content of experimentally induced wound in mice

Summary.The factors participating to the wound healing are complex and still obscure. Among these factors, epidermal growth factor (EGF) and histamine by increasing reepithelization and reparation tissue strength via enhancing collagen deposition to the wound site have a beneficial effect. This study was performed to investigate the effect of EGF dosage forms on the histamine content of the experimentally induced wound and some wound healing criters in the mice.Histological investigation of reepithelization, wound tensile strength for healing and collagen maturation, and histamine levels were assessed in the present study. Thirty two mice were divided into control, and EGF treated groups. Controls included three subgroups; untreated (n=5), 0.9% NaCl applied (n=5), and gel applied (n=5). Experimental groups were treated with two forms of EGF; EGF, solution form in 0.9% NaCl (n=5) and the gel form in 0.2% w/w in carbopol 940 (n=7). The discrepancy between these forms were evaluated. This evaluation was done by the application of two forms of EGF for 15 days on experimentally induced wound healing.Gel form of EGF by sustained release from bioadhesive polymer is found to be more effective than the soluble form, on the healing of the wound, by acceleration of reepithelization and increment of wound tensile strength. The tensile strength of the wound indicates the rate of repair and collagen maturation. It has been observed that when physiological saline and carbopol 940 exposed to incision without EGF causes a significant increase in tissue histamine content.According to the results of the present investigation; the histamine content is found to be decreased by EGF gel dosage form treatment, therefore preventing abnormal collagen formation has a beneficial effect on wound healing.

The effect of intracerebroventricular injection of beta amyloid peptide (1-42) on caspase-3 activity, lipid peroxidation, nitric oxide and NOS expression in young adult and aged rat brain.

AIM Intracerebroventricular (icv) administration of beta amyloid peptide (Aβ) in rats can be used to model certain aspects of Alzheimer disease (AD).The purpose of this study was to examine the effects of intracerebroventricular Aβ (1-42) peptide injection on caspase-3 activity and expression of nNOS and iNOS, malondialdehyde (MDA), glutathione (GSH) and NOx in the hippocampus, temporal cortex and parietal cortex. MATERIAL AND METHODS Groups were defined as 1) young adult control, 2) Aβ (1-42) injected young adult, 3) aged control and 4) Aβ (1-42) injected aged group. Stereotaxic surgery was performed. Aβ (1-42) peptide (5μg/1μl, in each icv) was administered bilateral intracerebroventricularly as a single injection. RESULTS Caspase-3 activity significantly increased in Aβ (1-42) injected aged rats when compared with young adult rats. Aβ (1-42) significantly increased lipid peroxidation in both young adult and aged rats. There was an increase in nNOS expression in the temporal cortex of Aβ (1-42) injected aged rats. CONCLUSION The most significant increase was seen in hippocampus in caspase-3 levels of the Aged- Aβ 1-42 group. nNOS expression in the hippocampus of aged rats was increased compared to young adult rats. However, nNOX expression in the hippocampus of Aβ (1-42) injected aged rats decreased significantly.

The Effect of Intrahippocampal Beta Amyloid (1‐42) Peptide Injection on Oxidant and Antioxidant Status in Rat Brain

Abstract:  In some animal models, cognitive impairment and neurodegenerative disorders that mimic Alzheimers disease (AD) can be reproduced by intracerebral or intracerebroventricular administration of peptide (Aβ) beta amyloid. Evidence suggests that oxidative stresses are involved in the mechanism of Aβ‐induced neurotoxicity and AD pathogenesis. Exposure to Aβ increases lipid peroxidation, protein oxidation, and the formation of hydrogen peroxide in cultured cells. Nitric oxide (NO) has significant physiological roles in the central nervous system and also it can be implicated in neurodegenerative diseases because of its free radical properties. The purpose of this study is to search the effects of intrahippocampal Aβ (1‐42) injection on malondialdehyde (MDA), glutathione (GSH), and nitrite plus nitrate (NOx) levels in temporal cortex and basal forebrain in rats. In this study, male adult Wistar albino rats were divided into two groups. Aβ (1‐42) peptide (10 μg/2 μL) was administered bilaterally as a single injection into the hippocampal fissure by a Hamilton microsyringe. Distilled water was administered to the control group by using the same procedure. Ten days after the Aβ (1‐42) injection, the rats were decapitated and brains were rapidly removed. MDA, GSH, and NOx levels were analyzed spectrophotometrically in temporal cortex and basal forebrain. MDA levels and NOx were increased 10 days after the injection of Aβ (1‐42) in temporal cortex and basal forebrain, but no statistical significance was found compared to control group. However, GSH levels were significantly higher in temporal cortex and basal forebrain in the Aβ (1‐42)‐injected group than the control group (P < 0.05). In conclusion, increased levels of GSH in temporal cortex and basal forebrain after the intrahippocampal Aβ (1‐42) injection show that a protective mechanism might develop due to oxidative stress.

Effect of taurine on wound healing.

SummaryTaurine which has antioxidant effects is also known to have effects on cell proliferation, inflammation and collagenogenesis. The aim of this study was to investigate the effect of taurine on incisional skin wounds.The mice incised on the dorsal area were divided into control and experimental groups. Saline was injected intraperitoneally to half of the animals in the control group and locally applied to the other half. Fifty mM taurine solution was given intraperitoneally to the first half of the experimental animals and locally to the second half of the experimental group.After four days of treatment, malondialdehyde (MDA) and histamine levels as well as the tensile strength of the wound tissue were measured. Structural alterations in epidermis and dermis were histologically evaluated.The locally administreated taurine significantly increased wound tensile strength by decreasing the MDA and histamine levels and prevented the degranulation of the mast cells. These observations suggest that taurine may be useful on wound healing.

Increased nitric oxide in exhaled air in patients with rheumatic heart disease

Endogenous production of nitric oxide and its presence in exhaled air was observed in humans. Prior studies have yielded contrasting information about the production of nitric oxide in patients with heart failure.

REGULATION OF FIBROGENESIS DURING THE EARLY PHASE OF COMMON BILE DUCT OBSTRUCTION

Background:  Both nitric oxide (NO) and prostaglandins have been proposed as inhibitor substances involved in collagen deposition in the hepatic parenchyma. The possible reciprocal connections between NO and eicosanoids in the development of liver fibrosis were investigated during the initial phase of common bile duct obstructions.

The effect of taurine administration on vitamin C levels of several tissues in mice

Summary.Taurine (2-aminoethane sulphonic acid), a sulphur-containing beta amino acid, is the most prevalent free intracellular amino acid in many human and animal tissues. Vitamin C metabolism is also fluenced by sulphur-containing amino acids. The aim of this study is to investigate the effect of taurine administration on the vitamin C levels of plasma and several tissues (brain, liver, kidneys) in mice with incisional skin wounds. Animals were divided into two as control and taurine groups. Taurine was freshly dissolved in sterile saline and administered daily (60 µl, ip) for five days in the taurine group. At the end of the fifth day, the animals were killed by decapitation. The brain, liver and kidneys were immediately removed. Vitamin C levels were measured in plasma and several tissues. The administration of taurine had no effect on the plasma vitamin C levels (P>0.05) but significantly increased in liver and kidneys (P<0.001). In conclusion, taurine may affect the vitamin C metabolism in tissues by different mechanisms.

Role of the nitric oxide pathway on ischemia-reperfusion injury in an isolated perfused guinea pig heart.

We examined the role of the nitric oxide (NO) pathway on ischemia-reperfusion injury with the use of isolated perfused guinea pig hearts. We administered to the heart either L-arginine or N-nitro-L-arginine methyl ester (L-NAME) before or after 20 min of ischemia, and we observed the heart rate, aortic pressure, and contractile force, as well as the levels of malondialdehyde (MDA) and glutathione (GSH). We observed that L-NAME increased the tissue MDA levels and aortic pressure. On the other hand, L-arginine before the onset of reperfusion decreased aortic pressure and tissue MDA levels but increased the tissue GSH levels. We concluded that L-arginine administration before the onset of reperfusion improves myocardial recovery from ischemic injury.