The effects of bupivacaine injection and oral nitric oxide on extraocular muscle in the rabbit

• Published in: Graefe's archive for clinical and experimental ophthalmology 2013-09, Vol.251 (9), p.2227-2233
• Main Authors: Bilgin, Burak, Gursoy, Huseyin, Basmak, Hikmet, Ozkurt, Mete, Tuncel, Nese, Canaz, Funda, Isiksoy, Serap, Colak, Ertugrul
• Format: Article
• Language: English
• Subjects: Administration, Oral; Anesthetics, Local - pharmacology; Animals; Bupivacaine - pharmacology; Hypertrophy; Injections, Intramuscular; Isosorbide Dinitrate - administration & dosage; Male; Medicine; Medicine & Public Health; Miscellaneous; Muscle Contraction - physiology; Muscle Fibers, Skeletal - pathology; Nitric Oxide Donors - administration & dosage; Oculomotor Muscles - drug effects; Ophthalmology; Rabbits
• ISSN: 0721-832X; 1435-702X
• DOI: 10.1007/s00417-013-2390-8

Aim Nitric oxide (NO) plays a key role in muscle regeneration, which is the primary response, observed during bupivacaine-induced extraocular muscle (EOM) hypertrophy. Our aims were to investigate the effects of bupivacaine injection into the rabbit EOM and the interaction with NO. Materials and methods Superior rectus (SR) muscles of 24 New Zealand albino rabbits were studied. Single muscle twitch tension (SMTT) and tetanic muscle tensions at 50, 75, and 100 Hz were recorded using a 15 V stimuli. The rabbits were equally allocated into three groups. Measurements were performed without any drug treatments in group 1. In groups 2 and 3, bupivacaine, 0.5 ml of a 0.50 % solution, was injected into the EOM, and after 21 days, measurements were performed. Oral isosorbide dinitrate (NO donor) at 20 mg/day was given each day prior to measurements in group 3. Results SMTTs were 69.9 (66.7–77.6), 187.7 (114.9–252.1) and 204.2 (135.3–311.6) mg in groups 1, 2, and 3 respectively. SMTTs for both groups 2 and 3 were significantly higher than that for group 1 ( p