The Effects of Daily Repeated Magnetic Field on S-Nitroso-N-acetyl-DL penicillamine Induced Hyperalgesia

Aim. The treatment of pain has been one of the most important objectives of medicine. We aimed to investigate antinociceptive effects and mechanisms of magnetic field (MF) on the hyperalgesia produced by S-Nitroso N-acetyl penicillamine (SNAP). Method. Study has been made in two sections. In the first section, rats were divided four groups (six in each). The first group was determined as sham group and administrated 0.3 mL, 0.9% NaCl intraperitoneally (i.p) before assessing tail flick latencies (TFLs) (Sham group). In the second group, 2 mg/kg SNAP administrated i.p. and TFLs were assessed at the same time points with first group (SNAP group). In the third group, rats were repeatedly exposed to MF for 6 consecutive days (MF group). In the fourth group, SNAP was administrated i.p everyday shortly before MF exposure (SNAP+MF group). In the second section, animals divided to the same groups with the first section. Same procedures have been performed with the first section groups and blood samples were collected to determine plasma levels of β-endorphin and substance P. Results. SNAP (2 mg/kg) produced hyperalgesic effect with i.p. administration. MF application (5 mT and 165 min per day) produced a strong antinociception in Days 3 and 4. Tail flick values of SNAP+MF in Days 3 and 4 were found to be significantly low as compared to MF and Sham groups. In SNAP group, substance P levels were found to be significantly high. Plasma β-endorphin levels in MF and SNAP+MF groups were significantly high as compared to the Sham group. Conclusion. MF may be an alternative antinociceptive approach for pain treatment. There is need for further studies to overcome the tolerance to antinociceptive effects of MF. Keywords: Hyperalgesia, magnetic field, snap, substance p, β-endorphin, tail flick Ozet Amac. Agri tedavisi tibbin en onemli hedeflerinden biridir. Bu arastirmada manyetik alan uygulamasinin S-Nitroso N-acetyl penicillamine (SNAP) tarafindan olusturulan agri uzerindeki etkilerini ve etki mekanizmasini arastirmayi amacladik. Yontem. Calisma iki kisim olacak sekilde tasarlandi. Birindi kisimda hayvanlar her birinde alti hayvan olacak sekilde 4 gruba bolundu. Birinci grup sham grubu olarak belirlendi ve bu hayvanlara 0,3 mL %0,9 NaCl tail flick latensleri olculmeden once uygulandi. Ikinci gruba (SNAP grubu) 2 mg/kg SNAP i.p. olarak enjekte edildi ve sham grubu ile ayni zaman noktalarinda tail flick olcumleri yapildi. Ucuncu grup (MF grubu) tekrarlayan alti gun boyunca manyetik alana maruz birakildi. Dorduncu grupta (SNAP+MF) hayvanlara manyetik alan uygulamasi yapilmadan hemen once 2 mg/kg SNAP i.p. olarak uygulandi. Calismanin ikinci kisminda ratlardan kan ornekleri alinarak kanlarinda supstance p ve B-endorfin seviyelerine ELISA yontemi ile bakildi. Bulgular. SNAP (2 mg/kg) anlamli bir hiperaljezi meydana getirerek tail flick latenleslerini kisaltti. Manyeteik alan uygulamasi (5 mT ve 165 dakika/gun) ozellikle 3. ve 4. gunlerde anlamli bir analjezi meydana getirdi. SNAP grubunda substance p seviyeleri yuksek bulunurken, manyetik alan grubunda B-endorfin seviyelerinin yuksek oldugu tespit edildi . Sonuc . Bu sonuclar manyetik alan uygulamasinin agri tedavisinde alternatif bir yaklasim olabilecegini gostermektedir. Fakat bu yontemin kullanilabilmesi icin gelisen toleransin ustesinden gelmenin yollarinin bulunmasi ve bunun icinde ileri arastirmalara gereksinim vardir. Anahtar sozcukler: Hiperaljezi, manyetik alan, snap, p maddesi, β-endorfin, tail flick