Biomedical subjects

Saadet Gumuslu

Publications and source records attributed to Saadet Gumuslu.

6 recordsLinked to original sources

PubMed2004

Application of a new chemiluminescence method for the determination of glucose-6-phosphate dehydrogenase activity in healthy and enzyme-deficient individuals.

INTRODUCTION: A chemiluminescence (CL) technique, which determines the glucose-6-phosphate dehydrogenase (G-6-PD) activities in healthy, heterozygous, and completely enzyme-deficient individuals was applied. METHODS: CL intensities were detected for 4 h at 15-min intervals in each sample with or without addition of G-6-PD substrates into the reaction mixture. RESULTS: The results revealed an inverse correlation to the reference UV method (Zinkham method; r=-0.80). Furthermore, the CL assay was able to detect G-6-PD activities as low as 0.2 IU/gHb, which was not possible by the UV method. DISCUSSION: In conclusion, we believe that this method offers a new diagnostic tool for the detection of G-6-PD activities in enzyme-deficient individuals and, because of its increased sensitivity, makes it amenable for determining the effects of different pharmaceutical agents on G-6-PD activity in tissue or cell cultures.

Erythrocytes↗

PubMed2003

The effect of different hypertension models on active avoidance learning.

This study tested the effects of different hypertension models on active avoidance learning in rats. Three-month-old male Wistar rats were divided randomly into six groups as follows: control (C), sham operated (sham), two kidney-one clip (2K-1C), one kidney-one clip (1K-1C), deoxycorticosterone-salt (DOCA), and N-omega-nitro-L-arginine-methyl ester (L-NAME) groups. Mean arterial blood pressures were significantly higher in four hypertensive groups compared with control and sham groups. The active avoidance training results indicated that hypertension state is associated with learning impairment. Thiobarbituric acid-reactive substances (TBARS) were determined as an indicator of lipid peroxidation in brain and hippocampus. Additionally, brain and hippocampus nitrite levels were studied.

Animals↗

PubMed2003

Effect of immobilization and cold stress on visual evoked potentials.

The main aim of our research was to study the effects of immobilization and/or cold stress on amplitudes and latencies of visual evoked potentials (VEPs) and thiobarbituric acid reactive substances (TBARS). Forty healthy male albino rats, aged three months, were used. The rats were equally divided into four groups: Control group (C), the group exposed to cold stress (CS), the group exposed to immobilization stress (IS), and the group exposed to both cold and immobilization stress (CIS). Plasma corticosterone concentrations were significantly increased in all stress groups. Lipid peroxidation was increased in brain and retina of all stress groups as indicated by the significant increase in TBARS levels compared to the C group. Glutathione peroxidase (GSH-Px) activity in brain and retina increased in the CS group, but decreased in the IS group relative to the C group. GSH-Px activity also increased in the brain, but not in the retina in the CIS group with respect to the C group. The mean latencies of P1, N1, P2, N2, and P3 components were significantly prolonged in all stress groups compared with the C group. The results suggest that stress induced lipid peroxidation may influence VEPs.

Animals↗

PubMed2002

Lipid peroxidation in rat brain during focal cerebral ischemia: prevention of malondialdehyde and lipid conjugated diene production by a novel antiepileptic, lamotrigine.

The effects of Lamotrigine (LTG) which blocks ischemia induced glutamate (Glu) release, on lipid peroxidation have been evaluated in cortical and cerebellar tissues of rat brain during focal cerebral ischemia. A total of 45 rats were randomly assigned into one of four groups; sham operated animals as controls, animals subjected to middle cerebral artery occlusion (MCAO) and treatment groups with LTG (20 mg/kg i.p.) either 30 min before or just after MCAO. Changes in lipid peroxides were expressed as nanomoles of malondialdehyde (MDA) and conjugated diene (CD) per milligram of protein. MDA values following 60 min of ischemia relative to contralateral cortex and CD levels in 0, 10 and 60 min of ischemia were found to be higher in the ipsilateral cortex than those in the contralateral cortex. On the other hand, contralateral cerebellar MDA levels after 0 and 60 min of ischemia and CD levels after 0, 10 and 60 min of ischemia were higher than those in the ipsilateral cerebellum. Pharmacological inhibition of Glu release significantly decreased the MDA and CD production in both cortex and cerebellum. Pre- or post-ischemic administration of LTG did not significantly change CD levels, but MDA levels in contralateral cortex were found to be significantly decreased than those in ischemic cortex in both pre- and post-treated group.

Animals↗

PubMed2002

The effects of NMDA receptor antagonist MK-801 on lipid peroxidation during focal cerebral ischemia in rats.

The effect of MK-801 on ischemic neuronal damage was studied in a rat model of permanent focal cerebral ischemia in terms of ipsilateral and contralateral cortical and cerebellar tissue lipid peroxides. Forty-five male Swiss Albino rats were assigned into one of four groups: sham operated as controls, subjected to right middle cerebral artery occlusion (MCAO) or injection of MK-801 (0.5 mg/kg i.p.) either 30 min before or just after right MCAO. Changes in lipid peroxides were expressed as nmol malondialdehyde (MDA) and conjugated diene (CD)/mg protein. MDA values after 60 min of ischemia relative to contralateral cortex and CD levels in 0, 10 and 60 min after ischemia were found to be higher in ipsilateral cortex than those in contralateral cortex. On the other hand, contralateral cerebellar MDA levels in 0 and 60 min of ischemia and CD levels in 0, 10 and 60 min after ischemia were found to be higher than those in ipsilateral cerebellum. Pharmacological inhibition of glutamate receptor by MK-801 before or just after permanent MCAO decreased significantly the MDA and CD levels in both cortex and cerebellum. Although no significant differences found in MDA values between rats pre- and posttreated with MK-801, CD levels in posttreated group seemed significantly lower than those in pretreated group. On the whole, these results suggest that MDA and CD represent early biochemical marker of lipid peroxidation in ischemic tissues, reflecting the radical-mediated tissue damage.

Alkenes↗

PubMed2002

The effect of different hypertension models on visual evoked potentials.

Even though there is an abundance of information about the complications of hypertension, studies of its influence on visual evoked potentials (VEPs) are rare. In previous studies, it was pointed out that hypertension induces changes on VEPs. However, it has not yet been clarified which models of hypertension are more effective on VEPs. The aim of this study was to investigate this subject in rats. Animals were divided equally into six groups: control group (C), sham operated (Sham), two kidney-one clip (2K-1C), one kidney-one clip (1K-1C), deoxycorticosterone-salt (DOCA), and N-omega-nitro-L-arginine-methyl ester (L-NAME) groups. Mean arterial pressure was significantly higher in four hypertensive groups compared with control and sham groups, but there were no significant differences either among hypertensive groups or between sham and control groups. At the end of the experimental period, flash visual evoked potentials were recorded. The mean latencies of P1, N1, P2, N2, and P3 components were significantly prolonged in all hypertensive groups compared with the control and sham groups. The mean latencies of all VEPs components in the L-NAME group were longer than in the other hypertensive groups. Thiobarbituric acid-reactive substances (TBARS) were determined as an indicator of lipid peroxidation. Our data showed that hypertension caused a significant increase of lipid peroxidation in brain and retinal tissues. Additionally, plasma renin activity (PRA) was highest in the 2K-1C group and lowest in the DOCA group.

Animals↗