Myosin ATPase activity in somatic muscle fibers in different degree of pH of the pre-incubation medium
Rekhacheva, I.P.
Arkhiv Anatomii Gistologii i Embriologii 99(10): 55-63
1990
ISSN/ISBN: 0004-1947 PMID: 2149923 Document Number: 358980
The problem on presence of muscle fibers (MF) types is an actual one, since it is a prerequisite to forecasting certain changes in MF under different conditions. The aim of the investigation has been to find out whether independent groups of MF exist or whether they react as a whole population to gradual changes in pH of the preincubational medium, when dynamic changes in m-ATPhase activity are studied. In serial transversal cryostate slices 10 mcm thick m-ATPhase activity has been defined in MF at preincubation of the slices in media having various pH. The experiment has had three series. In the I--the ventral denticulate muscle with universal biomechanical properties has been investigated; preincubation has been carried out in media having pH from 3.0 up to 11.0 with the intervals 0.5 pH. In the II--besides the muscle mentioned the fast brachial muscle and the force triceps muscle have been studied; preincubation has been performed only at pH 9.5, since in the I series two dissociated groups of MF have been distinguished. In the III series, at studying the same three muscles m-ATPhase activity has been detailed with their preincubation at pH from 3.8 up to 4.5 with the interval 0.1. The m-ATPase activity begins to manifest in various MF at pH of the preincubational medium within the limits of 3.8-4.2. A gradual increase in amount of MF that are revealing, as pH is gradually increasing, evidences most likely against independence of separate groups.