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The initial kinetics of NH3/NH4+ efflux from L3 Teladorsagia circumcincta


Muhamad, N and Walker, LR and Pedley, KC and Simcock, DC and Brown, S, The initial kinetics of NH3/NH4+ efflux from L3 Teladorsagia circumcincta, Parasitology International, 61, (3) pp. 487-492. ISSN 1383-5769 (2012) [Refereed Article]

Copyright Statement

Crown Copyright 2012

DOI: doi:10.1016/j.parint.2012.04.003


The initial rate of NH3/NH4+ accumulation in a medium containing L3Teladorsagia circumcincta was 0.180.6 pmol h− 1 larva− 1, which increased linearly with larval density. However it appeared that the larva-generated external concentration of NH3/NH4+ did not exceed about 130 M. The rate of NH3/NH4+ accumulation increased with temperature between 4 C and 37 C, declined with increasing pH or increasing external NH3/NH4+ concentration and was not significantly affected by the concentration of the phosphate buffer or by exsheathing the larvae. We infer from these data that the efflux of NH3/NH4+ is a diffusive process and that the secreted or excreted NH3/NH4+ is generated enzymatically rather than dissociating from the surface of the nematode. The enzymatic source of the NH3/NH4+ is yet to be identified. Since the concentration of NH3/NH4+ in the rumen and abomasum is higher than 130 M, it is unlikely that T. circumcincta contributes to it, but NH3/NH4+ may be accumulated from the rumen fluid by the nematode.

Item Details

Item Type:Refereed Article
Keywords:Teladorsagia circumcincta; Parasite; Diffusion; Kinetics
Research Division:Biological Sciences
Research Group:Biochemistry and cell biology
Research Field:Enzymes
Objective Division:Animal Production and Animal Primary Products
Objective Group:Livestock raising
Objective Field:Sheep for meat
UTAS Author:Brown, S (Dr Simon Brown)
ID Code:82445
Year Published:2012
Web of Science® Times Cited:2
Deposited By:Health Sciences A
Deposited On:2013-02-04
Last Modified:2013-05-03

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