Morphologic and morphometric evaluation of experimental acute crush injuries of the sciatic nerve of rats.
In order to qualify and quantify nerve fiber lesion following an acute crush injury, a morphologic and morphometric study was carried out in 25 Wistar rats divided into five groups of five animals each according to the crushing load applied, i.e., 500, 1,000, 5,000, 10,000, and 15,000 g. The injury was produced under general anesthesia on a 5mm-long intermediate segment of the right sciatic nerve for 10 min using a dead-weight machine. The animals were killed with an excessive dose of anesthetics 72 h later and submitted to perfusion with a fixing solution through the abdominal aorta immediately after death. Both the right and left sciatic nerves were removed and prepared for histologic and morphometric examinations; 5 microm-thick sections stained with 1% Toluidine blue were examined under a light microscope equipped with a video camera linked to a computer loaded with a graphic program (KS 400). The morphometric studies included measuring total number of fibers, fiber density, fiber diameter, myelin fiber area, axon diameter, axon area and G ratio. The results showed that damage to the nerve fibers began to appear as early as with the 500 g load and was similar in all groups despite the load applied, increasing with the 10,000 and 15,000 g loads, although the external supporting tissues and small diameter fibers were preserved. The predominant type of lesion produced was axonotmesis.
Mazzer
Patrícia Yume Cantalejo Nagima
PY
The Laboratory of Microsurgery, Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto School of Medicine, São Paulo University, 14049-900 Ribeirão Preto (SP), Brazil.
Barbieri
Cláudio Henrique
CH
Mazzer
Nilton
N
Fazan
Valéria Paula Sassoli
VP
D000208:Acute Disease; D000818:Animals; D001369:Axons / Q000473:pathology; D004396:Coloring Agents; D004195:Disease Models, Animal; D019044:Image Cytometry / Q000295:instrumentation / Q000379:methods*; D008297:Male; D018715:Microscopy, Video / Q000379:methods; D009409:Nerve Crush / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000293:injuries* / Q000473:pathology* / Q000503:physiopathology; D020426:Sciatic Neuropathy / Q000473:pathology* / Q000503:physiopathology; D012984:Software / Q000592:standards; D013194:Staining and Labeling; D014048:Tolonium Chloride; D014855:Wallerian Degeneration / Q000209:etiology / Q000473:pathology / Q000503:physiopathology
D004396:Coloring Agents; D014048:Tolonium Chloride