Alteration of Glucose Metabolism in the Spinal Cord of Experimental Lead Poisoning Rats. Microdetermination of Glucose Utilization Rate and Distribution Volume.

Abstract

To examine the effects of lead on glucose metabolism in the spinal cord, glucose utilization rate (GUR) and distribution volume of glucose (DV) in the anterior horn and white matter were determined in 9 rats exposed to lead for 4 weeks and 10 control rats. The GUR and DV were determined by the quantitative microdetermination method using non-tracer amount of 2-deoxyglucose based on the three-compartments model of Sokoloff. The GUR and DV in the anterior horn in the lead-exposed rats were significantly lower than those in the controls. It is thus suggested that glucose metabolism, as measured by the GUR and DV, in the anterior horn is inhibited by lead; the anterior horn cells seem sensitive to lead neurotoxicity. . Uptake of glucose analog (3-O-methylglucose) by the MEly cells (a cell line of mouse cerebral microvessel endothelium) was inhibited after the cells were incubated with a medium containing 10 -4 M of lead for 2 days 3). As a more acute effect, Bertoni and Sprenkle (1988) 4) demonstrated the decrease of glucose utilization rate (GUR) in the medial geniculate bodies, inferior colliculus and sensory cortex of the brain of rats 45 min after intravenous injection of lead acetate, when the animals showed BPb concentrations of about 160 µg/dl, using the 2-deoxyglucose autoradiographic method.R e c e n t l y, t w o o f t h e a u t h o r s d e v e l o p e d a

In vitro and In vivo Studies on Mulberry Extracts: Evaluation of Chemical and Anticancer Activities and Attenuation of Lead Toxicity

“…The average values of cholesterol, triglycerides and glucose of treated rats in all groups are presented in Table 4 Administration of 500 mg lead/L in drinking water significantly (P <0.05) induced time dependent elevation in cholesterol, triglyceride and glucose compared to control and all other treated groups after 4 weeks of treatments. Similar deleterious effect of lead on metabolism were reported by Yokoyama, et al [46] Hamadouche, et al [47] and Newairy and Abdou [48] where lead at different doses and intervals was shown to reduce the rate of glucose metabolism and elevate cholesterol and triglycerides. In present work, Intake of leaves or fruits extracts induced significant (P <0.05) timedependent reduction in these three parameters.…”

Metal Concentrations in Cerebrospinal Fluid and Blood Plasma from Patients with Amyotrophic Lateral Sclerosis

“…The level of motor nerve injury in slow Pb intoxication has been a controversy for two centuries (Beritic 1984) however it seems justified to settle a topical diagnosis of Pb intoxication to the anterior horn cells of the spinal cord , the same cells that are affected in ALS. Experimental findings (Yokoyama et al 2000) confirm that anterior horn cells are selectively sensitive to Pb neurotoxicity. Reduced motor amplitudes, seen in both disorders, are a consequence of anterior horn cell degradation, and fibrillation potentials indicating denervation, are found in both (Seppalainen and Hernberg 1972).…”

Prophylactic Effects of Melatonin in Lead Induced Toxicity in Rats

“…Daily administration of 100 mg/kg lead acetate to rats, reduce their total body weights compared with control animals with subsequent elevation of organ/body weight ratios, and treatment with melatonin restores body weights and impaired organ/total body weight ratio. Lead poisoning is very well known to affect numerous organ systems, and is associated with a number of morphological, biochemical and physiological changes that include kidney dysfunction, impaired glucose metabolism, CNS disturbances, impairment of liver function and hematological disorders [12] . Among their effects, the impaired glucose metabolism is considered as a major pathway that may be followed by changes in total body or organ weights; in this respect intoxication with lead reduces the rate of glucose metabolism, with consequent reduction of the required energy for many anabolic process [13] , and the profound decrease in serum glucose level which is reported in rabbits intoxicated with lead, might also be a cause for tissue wasting due to inappropriate availability of energy.…”