Diaphragmatic fatigue is associated with decreased inositol 1,4,5-trisphosphate formation.
The ability of the rat diaphragm to produce inositol 1,4,5-trisphosphate (InsP3) in response to a maximal contractile stimulus was determine in vitro in both fatigued and nonfatigued diaphragms. InsP3 was produced during a maximal contraction of the diaphragm. After inducing fatigue, there was a significant reduction in the production of InsP3 compared with that in nonfatigued muscle. The maximal force generated by the diaphragm was also decreased after fatigue. A significant positive linear correlation was found between the force developed by the diaphragm and the amount of InsP3 liberated.
Zavecz
J H
JH
Department of Pharmacology, Louisiana State University Medical Center, Shreveport 71130.
Anderson
W M
WM
Phillips
K
K
McNatt
L
L
D000818:Animals; D003964:Diaphragm / Q000378:metabolism* / Q000502:physiology; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D009119:Muscle Contraction; D051381:Rats; D011919:Rats, Inbred Strains
D015544:Inositol 1,4,5-Trisphosphate