Possible mechanisms of changing in the functional properties of a mouse diaphragmal muscle strip for protein sensitization

The mechanisms of influencing the organism allergic reorganization on the contractile function of a mouse diaphragm (MD) muscle strip have been studied. In has been demonstrated that in case of protein sensitization (PS) the increase of the power of the contraction (PC) produced by cholinomimetic carbacholinum (ChC) in MD in vitro is observed, as well as the decrease of acetylcholine (ACh) nonquantum secretion (NQS) in the zone of end plate. PC increase under ChC is a consequence of the cholinomimetic sensitivity increase of muscle fiber postsynaptic membrane due to the decrease of ACh NQS in the zone of end plate. Exogenous ATP also increases PC and decreases ACh NQS of MD in both intact and sensitized mice. The vector of muscle PC dynamics under the cholinomimetic correlates with ACh NQS for all the variants of experimental influence. However, the extent of these changes in the muscle of a sensitized animal is less pronounced than in a non-sensitized animal. It is speculated that the lesser variability of functional properties caused by ATP in MD of sensitized mice compared with control is an evidence of developing mechanisms of the resistance for external loads in respiratory muscles, which appears for bronchospastic syndrome and bronchial asthma.