The influence of systemic factors on acrylamide-induced changes in brain, nerve, and other tissues.

In order to define the locus of acrylamide neurotoxicity, the effects of chronic intoxication (total dose 500 mg/kg) on cholinergic synthesis and transport, the Schwann cell-myelin complex, lysosomal activity, and several metabolic pathways were determined in rat sciatic nerve, spinal cord, and brain. No changes were found in hematological measures or in the levels of clinically important blood enzymes, indicating no major damage to other organs. The activities of choline acetyltransferase (ChAT), 2',3'-cyclic nucleotide phosphohydrolase, beta-glucuronidase, and lactate dehydrogenase were unaffected in acrylamide paralyzed animals, but creatine kinase (CK) decreased in sciatic nerve, muscle, and brain, particularly in animals dying of the intoxication.

Enzyme changes in axon, myelin, and Schwann cells in injured sciatic nerve.

Four enzymes related to specific cell functions were assayed in rat sciatic nerve injury by crush (cr) or crush and ligation (cr-lig) after 2, 7, and 15 days in situ. Enzyme activities in segments of sciatic nerve proximal and distal to the injury were compared to those in corresponding segments of the contralateral nerve. Choline acetyltransferase (CAT) activity in the distal portion decreased by 65% for cr and almost to zero for cr-lig by day 7, while in the proximal portions CAT decreased to 70% of control values by 7 days and to 50% at 15 days after cr-lig.

Regional activities of metabolic enzymes and glutamate decarboxylase in human brain.

Interpretation of biochemical measurements in the human brain after death is complicated by a variety of premortem, perimortem, and postmortem factors. The activity of glutamic acid decarboxylase (GAD) in particular has been found to vary considerably among human brains. In contrast to neurotransmitter-associated enzymes, metabolic enzymes are present in all brain cells and should not be specifically lost by patterned neuronal cell loss such as that which occurs in Parkinson disease.

2', 3'-cyclic nucleotide 3'-phosphodiesterase in cerebrospinal fluid.

The activity of the myelin-associated enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) was assayed in the cerebrospinal fluid (CSF) of 107 neurologic patients by a new and sensitive fluorometric method. The activity of CNP was about 20 nmol per hour per milligram protein or 12 nmol per hour per milliliter CSF. At these extremely low levels, the presence of even a small amount of blood (which has slightly greater activity) significantly elevated CNP values.