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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2003-12-10
pubmed:abstractText
Parathyroid hormone (PTH) is secreted by the chief cells of the parathyroid gland in response to changes in ionized calcium (Ca(2+)) concentrations. In this study, we measured PTH secretion, and PTH mRNA and calcium-sensing receptor (CaR) mRNA expression by equine parathyroid chief cells in vitro. We also evaluated the effects of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha on PTH secretion, and PTH and CaR mRNA expression. The relationship between PTH and Ca(2+) was inversely related. PTH secretion decreased from 100% (day 0) to 13% (day 30). PTH mRNA expression declined from 100% (day 0) to 25% (day 30). CaR mRNA decreased from 100% (day 0) to 16% (day 30). Chief cells exposed to high (2.0 mM) Ca(2+) concentrations had a lower PTH mRNA expression compared with low Ca(2+) concentrations. Ca(2+) concentrations had no effect on CaR mRNA expression. The inhibitory effect of high Ca(2+) concentrations on PTH secretion also declined over time. After day 10, there was no significant difference in PTH secretion between low and high Ca(2+ )concentrations. IL-1beta decreased both PTH secretion (75%) and PTH mRNA expression (73%), and resulted in a significant overexpression of CaR mRNA (up to 142%). The effects of IL-1beta were blocked by an IL-1 receptor antagonist. IL-1beta decreased the Ca(2+) set-point from 1.4 mM to 1.2 mM. IL-6 decreased PTH secretion (74%), but had no effect on PTH and CaR mRNA expression. TNF-alpha had no effect on PTH secretion, and PTH and CaR mRNA expression. In summary, the decreased responsiveness of parathyroid cells to Ca(2+) from 0 to 30 days can be explained, in part, by the reduced CaR expression. IL-1beta and IL-6 but not TNF-alpha affected parathyroid function in vitro and may be important in influencing PTH secretion in the septic horse.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0952-5041
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
609-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Parathyroid hormone (PTH) secretion, PTH mRNA and calcium-sensing receptor mRNA expression in equine parathyroid cells, and effects of interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha on equine parathyroid cell function.
pubmed:affiliation
Department of Veterinary Biosciences, College of Veterinary Medicine, 1925 Coffey Road, The Ohio State University, Columbus, Ohio 43210, USA. toribio.1@osu.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't