Abstract
A peripheral neuropathy was induced in F/Crl BR inbred albino rats by the oral administration of coyotillo extract (Karwinskia humboldtiana). The progression of the disorder was modified by the separate administration of a pyridoxine deficient diet, pyridoxine supplementation, phenobarbital, and hydrocortisone. Neurological function was measured clinically by daily performance on a rotating rod (rotarod apparatus). Pathologic alteration was determined both by light and electron microscopic techniques. A dietary restriction of pyridoxine hastened onset of neurologic dysfunction, while supplementation with pyridoxine or administration of phenobarbital significantly delayed onset of neurological damage. The administration of hydrocortisone, while delaying the onset of failure (p<.05), did not increase the amount of extract required to induce failure. Coyotillo extract was administered to pyridoxine deficient rats at 2 dosage levels (40 mg/kg and 25 mg/kg); extract was given to the remaining groups at the lower dosage rate. Convulsions were observed within the experimental group of deficient rats at the higher dosage level, but no seizures were observed in subsequent experimental groups at the reduced coyotillo levels. Statistical data for the mean day of failure/mean dose for failure were as follows: High dosage study-abnormal (coyotillo) control, 20.1 days/17.3 mg; pyridoxine deficiency, 15.5 days/11.9 mg. Low dosage study-abnormal (coyotillo) control, 32.8 days/15.7 mg; pyridoxine deficiency, 26.3 days/11.3 mg; pyridoxine supplement, 44.4 days/22.2 mg; phenobarbital, 45.8 days/25.0 mg; hydrocortisone, 42.1 days/15.3 mg..
Joiner, Gary Nelson (1976). A study of experimentally induced coyotillo neuropathy and its modification in inbred rats. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -475200.