Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive and ultimately fatal disorder characterized by predominant degeneration of the upper and lower motor neurons of the brain and the spinal cord. ALS is a disease of middle and late onset and its common incipient symptoms are gait disturbance, limb weakness, dysarthria or dysphagia. Death usually occurs with in 3 years from onset. No medical therapy leads the duration of illness. It is also found that the skin feels supple, like tanned leather, and loses elasticity. In addition, ALS patients do not develop bedsores even in advanced stages. We have, therefore, studied the ratio of type I/III collagen in the skin from ALS patients. A portion of the autopsy sample was cut in a plane. Sample was placed in 0.5ml of 1mg/ml solution of pepsin in 0.1M acetic acid, adjusted to pH 2.4 with HCl. Then, pepsin digestion of the sample was done at 4°C for 48 hours. The sample was electrophoresed at 5% polyacrylamide gel in the presence of sodium dodecyl sulfate. Identification of collagen types was carried out by the method of Chan and Cole. With the densitometric measurements, there was a higher concentration of type III collagen than that of type I collagen in the skin of ALS patients (p<0.05). In addition, a significant increase of type III collagen was found in ALS with longer duration of illness (r=0.96, p<0.02). Therefore, our data suggest that the ratio of type I to type III collagens may be altered in the skin of ALS.
