CALCIUM ADENOSINE 5’ TRIPHOSPHATASE ENZYME ACTIVITY IN EXTRAOCULAR MUSCLES IN STRABISMUS

Öz

OBJECTIVE: This study aims to assess and compare the level of the calcium adenosine 5’-triphosphatase (Ca2+-ATPase) enzyme activity in resected extraocular muscles of strabismus and control groups.
MATERIAL AND METHODS: The level of Ca2+-ATPase enzyme activity was evaluated in the extraocular horizontal muscles resected from twenty eyes of 19 patients who underwent strabismus surgery (group 1) and extraocular horizontal muscles samples taken from five eyes of 5 corneal transplant donors (control group - group 2). Enzyme activity was measured via inorganic phosphate (Pi) levels released during Ca2+-ATPase activity.
RESULTS: The average activity was calculated as 100.07±12.75 nmol Pi mg-1 0.90min-1 in group 1 and as 165.94±13.60 nmol Pi mg-1 0.90 min-1 in group 2. The enzyme activity in group 1 was significantly lower than in group 2 (p <0.01).
CONCLUSIONS: The low level of Ca2+-ATPase enzyme activity in muscles that were resected during strabismus surgery might be an indicator for their possible role in pathophysiology of strabismus.

Anahtar Kelimeler

• Strabismus,
• Extraocular muscle
• Ca2+-ATPase

Proje Numarası

TF 97 U9

ŞAŞILIKTA EKSTRAOKÜLER KASLARDA KALSİYUM ADENOZiN 5’ TRiFOSFATAZ AKTİVİTESİ

Öz

AMAÇ: Bu çalışma extraoküler kaslardaki kalsiyum adenozin 5’-trifosfataz Ca2+-ATPaz enzim aktivite düzeyinin şaşılık ve kontrol gruplarında değerlendirilmesi ve karşılaştırılması amaçlamıştır.
GEREÇ VE YÖNTEM: Şaşılık grubu (grup 1), horizontal kaslarına rezeksiyon yapılan 19 hastanın 20 gözünden oluşmuştur. Daha önce organ nakli için gözünü bağışlamış, ölüm nedeni belli, herhangi bir sistemik ya da göz hastalığı olmayan 5 göz ise kontrol grubu (grup 2) olarak alınmıştır. Her iki gruba aynı miktarda rezeksiyon uygulanmıştır. Enzim aktivitesi, Ca2+-ATPaz aktivitesi sırasında açığa çıkan inorganic fosfat (Pi) düzeyi ile ölçülmüştür.
BULGULAR: 'Grup 1’de ortalama aktivite 100.07 ± 12.75 Pimg-1 0.90 min-1 olarak ölçülürken, Grup 2’de 165.94 ± 13.60 nmolPi mg-1 0.90 min-1 olarak ölçülmüştür. Grup 1’ de enzim aktivitesi, grup 2’ye gore istatistiksel olarak anlamlı düzeyde daha düşük bulunmuştur (p < 0.01).
SONUÇ: Şaşılık cerrahisi sırasında rezeke edilen kaslarda düşük Ca2+-ATPaz enzim aktivitesinin bulunması şaşılık patofiyolojisindeki olası rolünün bir göstergesi olabilir.

Anahtar Kelimeler

• Şaşılık
• Extraoküler kas
• Ca2+-ATPase

Destekleyen Kurum

Çukurova Üniversitesi Çukurova Tıp Fakültesi

Proje Numarası

TF 97 U9

Kaynakça

1. Shimko JF. Binocular vision and ocular motility theory and management of strabismus. American Orthoptic Journal 2017; 51(1):161–62.
2. Zeiger U, Mitchell CH, Khurana TS. Superior calcium homeostasis of extraocular muscles. Experimental eye research 2010;1;91(5):613-22.
3. Reading HW, Isbir T. Action of lithium on ATP-ase in transmitter release from rat iris. Biochem Pharmacol 1979; 28: 3471–77.
4. Reading HW, Isbir T. The role of cation-activated ATP-ase in transmitter release from rat iris. Quart J Exper Physiol 1980; 65:105–116.
5. Atkinson A, Gatenby AD, Lowe AG. The determination of inorganic orthophosphate in biological systems. Biochimica et Biophysica Acta 1973; 320(1):195-204.
6. Lowry OH, Rosenbrough NJ, Farr AL, et al. Protein measurement with the folin phenol reagent. J Biol Chem 1951;193:261.
7. Asmussen G. Functional morphology and physiology of the eye muscles. InKaufmann H, Ed. Transactions of the16th Meeting of the European Strabismological Association, Giessen, Germany, 18, Sep. 1987;11.
8. Breinin GM. The structure and function of extraocular muscle–an appraisal of the duality concept. The Gifford Memorial Lecture. Am J Ophthalmol 1971;72:1.

9. Lennerstrand G: Motor units in eye muscles. In Lennerstrand G, Bach-y-Rita P, eds: Basic Mechanisms of Ocular Motility and Their Clinical Implications. New York, Pergamon Press,1975;119.
10. Richmond FJ, Johnston WS, Baker RS, et al. Palisade endings in human extraocular muscles. Invest Ophthalmol Vis Sci 1984;25:471.
11. MacLennan DH, Brand1 CJ, Korczak B, et al. Aminoacid sequence of a Ca2+Mg+2 dependent ATPase from rabbit muscle sarcoplasmic reticulum, deduced from its complementary DNA sequence. Nature 1985; 316:696-700.
12. Fischer MD, Gorospe JR, Felder E, et al. Expression profiling reveals metabolic and structural components of extraocular muscles. Physiol Genomics 2002;9:71–84.
13. Kjellgren D, Ryan M, Ohlendieck K, et al. Sarco(endo)plasmic reticulum Ca2+ ATPases (SERCA1 and -2) in human extraocular muscles. Invest Ophthalmol Vis Sci 2003;44:5057–5062.
14. Lennerstrand G. Strabismus and eye muscle function. Acta Ophthalmol 2007;85:711-23.
15. Hoffman EP, Knudson CM, Campbell KP, Kunkel LM. Subcellular fraction of dystrophin to the triads of skeletal muscle. Nature 1987; 330:754-58.
16. Benders AA, Veerkamp JH, Oosterhof A, et al. Ca2+ homeostasis in Brody's disease. A study in skeletal muscle and cultured muscle cells and the effects of dantrolene an verapamil. J Clin Invest 1994; 94:741-48.
17. Kim HS, Chang YH, Kim DH, et al. Calcium up take and release through sarcoplasmic reticulum in the inferior oblique muscles of patients with inferior oblique overaction. Yonsei Med Journal 2006; 47:207-13.
18. Chiarandini DJ: Activation of two types of fibers in rat extraocular muscles. J Physiol (Lond) 1976; 259: 299.
19. Jacoby J, Ko K. Sarcoplasmic reticulum fast Ca2+-pump and myosin heavy chain expression in extraocular muscles. Invest Ophthalmol Vis Sci 1993;34:2848–58.