Chloroform extract of hog barn dust modulates skeletal muscle ryanodine receptor calcium-release channel (RyR1)

Tian, C; Shao, CH; Fenster, DS; Mixan, M; Romberger, DJ; Toews, ML; Bidasee, KR

HERO ID

2584187

Reference Type

Journal Article

Year

2010

Language

English

PMID

20576841

HERO ID 2584187
In Press No
Year 2010
Title Chloroform extract of hog barn dust modulates skeletal muscle ryanodine receptor calcium-release channel (RyR1)
Authors Tian, C; Shao, CH; Fenster, DS; Mixan, M; Romberger, DJ; Toews, ML; Bidasee, KR
Journal Journal of Applied Physiology (1985)
Volume 109
Issue 3
Page Numbers 830-839
Abstract Skeletal muscle weakness is a reported ailment in individuals working in commercial hog confinement facilities. To date, specific mechanisms responsible for this symptom remain undefined. The purpose of this study was to assess whether hog barn dust (HBD) contains components that are capable of binding to and modulating the activity of type 1 ryanodine receptor Ca2+-release channel (RyR1), a key regulator of skeletal muscle function. HBD collected from confinement facilities in Nebraska were extracted with chloroform, filtered, and rotary evaporated to dryness. Residues were resuspended in hexane-chloroform (20:1) and precipitates, referred to as HBDorg, were air-dried and studied further. In competition assays, HBDorg dose-dependently displaced [3H]ryanodine from binding sites on RyR1 with an IC50 of 1.5±0.1 microg/ml (Ki=0.4±0.0 microg/ml). In single-channel assays using RyR1 reconstituted into a lipid bilayer, HBDorg exhibited three distinct dose-dependent effects: first it increased the open probability of RyR1 by increasing its gating frequency and dwell time in the open state, then it induced a state of reduced conductance (55% of maximum) that was more likely to occur and persist at positive holding potentials, and finally it irreversibly closed RyR1. In differentiated C2C12 myotubes, addition of HBD triggered a rise in intracellular Ca2+ that was blocked by pretreatment with ryanodine. Since persistent activation and/or closure of RyR1 results in skeletal muscle weakness, these new data suggest that HBD is responsible, at least in part, for the muscle ailment reported by hog confinement workers.
Doi 10.1152/japplphysiol.00123.2010
Pmid 20576841
Wosid WOS:000281958800026
Is Certified Translation No
Dupe Override No
Comments Scopus URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957147718&doi=10.1152%2fjapplphysiol.00123.2010&partnerID=40&md5=430a6c62a32832fd8fee785c293360b0
Is Public Yes
Language Text English
Keyword muscle weakness; single channel; binding; C(2)C(12) cells