Evaluation of HemogloBind<sup>TM</sup> treatment for preparation of samples for cholinesterase analysis

Abstract

Acetylcholine is an essential neurotransmitter found throughout the nervous system. Its action on postsynaptic receptors is regulated through hydrolysis by various carboxylesterases, especially cholinesterases (ChEs). The acute toxicity of organophosphate (OP) compounds is directly linked to their action as inhibitors of ChE. One widely used assay for evaluating ChE activity is a spectrophotometric method developed by Ellman et al. When the enzyme source is from tissues or, in particular, blood, hemoglobin displays a spectrophotometric peak at the same wavelength used to analyze cholinergic activity. This creates a substantial background that interferes with the Ellman’s assay and must be overcome in order to accurately monitor cholinesterase activity. Herein, we directly compare blood processing methods: classical method (1.67 ± 0.30 U/mL) and HemogloBind™ treatment (1.51 ± 0.17 U/mL), and clearly demonstrate that pretreatment of blood samples with Hemoglobind™ is both a sufficient and rapid sample preparation method for the assessment of ChE activity using the Ellman’s method.

Efficacy of Recommended Prehospital Human Equivalent Doses of Atropine and Pralidoxime Against the Toxic Effects of Carbamate Poisoning in the Hartley Guinea Pig

“…(10). Briefly, whole blood samples were treated with HemogloBind™ to remove hemoglobin – which interferes with the ChE activity assay due to spectral overlap.…”

A comprehensive evaluation of the efficacy of leading oxime therapies in guinea pigs exposed to organophosphorus chemical warfare agents or pesticides

“…Terminal blood samples were collected and processed for all survivors using Hemoglobind ™ (McGarry et al 2013). For each animal, the relative AChE activity level (RA AChE ) was calculated as the Ellman assay acetylthiocholine turnover rate in a terminal blood sample divided by the turnover rate in the baseline blood sample (Ellman et al 1961).…”

Acute toxicity of phorate oxon by oral gavage in the Sprague-Dawley rat

“…From the chilled blood samples, two 80-µL aliquots of whole blood were removed, diluted, and treated with Hemoglobind™ (Biotech Support Group LLC, Monmouth Junction, NJ, USA) to remove hemoglobin for later assay for cholinesterase activity (McGarry et al ., 2013). Half (~1 mL) of the remaining blood sample was centrifuged to obtain plasma for PHO concentration analysis, and the remaining whole blood was processed for PHO concentration analysis via LC/MS/MS (detection limit: 0.5 ng/mL).…”