Alkaline phosphatase in nasal secretion of cattle: biochemical and molecular characterisation.
BACKGROUND
Nasal secretion (NS) was investigated as a source of information regarding the mucosal and systemic immune status of cattle challenged by respiratory disease. A method for the collection of substantial volumes (~12 ml) of NS from cattle was developed to establish a reference range of analytes that are present in the NS of healthy cattle. Biochemical profiles of NS from a group of 38 healthy Holstein-Friesian cows revealed high alkaline phosphatase (AP) activity of up to 2392 IU/L. The character and source of the high activity of AP in bovine NS was investigated.


RESULTS
Histochemical analysis confirmed the localization of the AP enzyme activity to epithelial cells and serous glands of the nasal respiratory mucosa. Analysis of mRNA levels from nasal mucosa by end point RT-PCR and PCR product sequencing confirmed that the AP was locally produced and is identical at the nucleotide level to the non-specific AP splice variant found in bovine liver, bone and kidney. Analysis by isoelectric focussing confirmed that AP was produced locally at a high level in nasal epithelium demonstrating that AP from nasal secretion and nasal mucosa had similar pI bands, though differing from those of the liver, kidney, bone and intestine, suggesting different post-translational modification (PTM) of AP in these tissues.


CONCLUSIONS
A nasal isozyme of AP has been identified that is present at a high activity in NS, resulting from local production and showing distinctive PTM and may be active in NS as an anti-endotoxin mediator.
Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Rd, Glasgow, G61 1QH, UK. m.ghazali.1@research.gla.ac.uk.
M Faizal
MF
Ghazali
Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Rd, Glasgow, G61 1QH, UK. caline.koh-tan@glasgow.ac.uk.
H H Caline
HH
Koh-Tan
School of Veterinary Medicine, University of Glasgow, Bearsden Rd, Glasgow, G61 1QH, UK. mark.mclaughlin@glasgow.ac.uk.
Mark
M
McLaughlin
Institute of Infection, Immunity and Inflammation, University of Glasgow, Bearsden Rd, Glasgow, G61 1QH, UK. paul.montague@glasgow.ac.uk.
Paul
P
Montague
Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Rd, Glasgow, G61 1QH, UK. nicholas.jonsson@glasgow.ac.uk.
Nicholas N
NN
Jonsson
Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Bearsden Rd, Glasgow, G61 1QH, UK. david.eckersall@glasgow.ac.uk.
P David
PD
Eckersall
D000469:Alkaline Phosphatase / Q000032:analysis* / Q000235:genetics; D000818:Animals; D012634:Bodily Secretions / Q000201:enzymology; D002417:Cattle / Q000378:metabolism*; D005260:Female; D007525:Isoelectric Focusing / Q000662:veterinary; D009297:Nasal Mucosa / Q000201:enzymology / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary
D020033:Protein Isoforms; D000469:Alkaline Phosphatase