Browsing by Author "Cansev, Mehmet"

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Kolin’in Merkezi ve Periferik Kolinerjik Nöronlarda ve Kolinerjik İletimdeki İşlevi
(Acıbadem Mehmet Ali Aydınlar Üniversitesi, 2010-04-01) Ulus, İsmail Hakkı; Cansev, Mehmet
ÖZET Kolin bir kuaterner amin olup, nörotrasmitter asetilkolinin ve membranın temel yapılarından fosfotidilkolin’in öncül maddesidir. Kolin ayrıca vücutta, metionin ve s-adenosilmetionin rejenerasyonu için gerekli metil gurupla rının vericisi olan, betaine de metabolize olur. Bu derlemede esas olarak kolin’in cholinergic noronal görevlerindeki rolü üzerinde durulacaktır. Kolinerjik nöronların asetilkolin sentezi için kulandıkları kolin esas olarak kaynağı dolaşımdır. Dolaşımdaki kolin’in düzeyi 6-8 saatlik açlık sonrası 10 μM kadardır. Bu düzey yemek sonrası, gıdalardaki kolin‘in miktarına göre, 20-60 μM kadar yükselebilir. Farmakolojik dozlarda tedavi ile de kan kolin düzeyi 200-300 μM kadar yükselebilir. Kolin’i asetilkoline dönüştüren enzim kolinasetiltrasferaz enzimi substratı kolini zayıf bir şekilde doyurulmuş olduğundan plazmada kolin düzeyinin yükselmesi asetilkolin sentezini arttırır. Kolin, yeterince yüksek düzeylerinde (0,5-100 mM gibi), muskarinik ve nikotinik asetikolin reseptörleri ile agonist olarak da etkileşir. Kolin te davisi nörotrasmitter asetilkolin’in sentez ve salıverilmesinde hızlanma ve merkezi ve periferik muskarinik ve nikotinik kolinerjik iletide yükselme ile sonuçlanır. Kolin, burada tartışılacak olan, kolinerjik nitelikte birçok fizyo lojik, farmakolojik ve nörokimyasal etkiler oluşturur.
Nutritional modifiers of aging brain function: use of uridine and other phosphatide precursors to increase formation of brain synapses
(2010-01-01) Wurtman, Richard J.; Cansev, Mehmet; Sakamoto, Toshimasa; Ulus, Ismael
Brain phosphatide synthesis requires three circulating compounds: docosahexaenoic acid (DHA), uridine, and choline. Oral administration of these phosphatide precursors to experimental animals increases the levels of phosphatides and synaptic proteins in the brain and per brain cell as well as the numbers of dendritic spines on hippocampal neurons. Arachidonic acid fails to reproduce these effects of DHA. If similar increases occur in human brain, administration of these compounds to patients with diseases that cause loss of brain synapses, such as Alzheimer's disease, could be beneficial.
Prevention of Epidural Fibrosis in Rats by Local or Systemic Administration of Citicoline
(TURKISH NEUROSURGICAL SOC, 2012-01-01) Savran, Mehmet; Bekar, Ahmet; Cansev, Mehmet; Tolunay, Sahsene; Ulus, Ismail Hakki; Taskapilioglu, Mevlut Ozgur
AIM: The objective of this study was to investigate the effect of citicoline administration on epidural fibrosis which is a frequent complication of lumbar disc surgery with no effective treatment or preventive surgical technique. MATERIAL and METHODS: Sixty Sprague-Dawley female rats undergoing L4-5 right hemilaminotomy and annular fenestration were arranged in three groups: rats in Group 1 (control group) and Group 2 (topical citicoline group) were applied 0,9\% saline and 100 mu M citicoline on surgical area, respectively, while rats in Group 3 (systemic citicoline group) received 600 mu mol/kg citicoline intraperitoneally. Rats were sacrificed four weeks later and their vertebral colons were removed en bloc. Groups were evaluated according to histological criteria and results were compared using statistical tools. RESULTS: Compared with control group, significantly less epidural fibrosis, dural adhesion, fibroblast cell density, foreign body reaction, and medulla spinalis retraction were observed in groups treated with topical and systemic citicoline (groups 2 and 3) (p < 0,001). No significant difference was found with regard to measured parameters between two treatment groups (p > 0,05). CONCLUSION: Our study demonstrates for the first time in the literature that citicoline may be effective for preventing postoperative epidural fibrosis. However, its mechanism of action and clinical effectiveness must be further investigated.