A histochemical analysis of mammalian oxidative skeletal muscle fibres using the enzymes of energetic metabolism

Summary Some histochemical parameters of the three main fibre types of rat vastus lateralis muscle were studied. Succinic dehydrogenase (SDH), creatine kinase (CK), sarcotubular ATPase (SR-ATPase) and mitochondrial ATPase activities were demonstrated in serial sections. The three fibre types, recognised by the distribution pattern of SDH activity, all show high CK activity. However, red Type I oxidative fibres when examined for ATPase and ATPase dependent CK activity, show distinct heterogeneity revealing sub-populations within the same homogeneous fibre type. Three distinct patterns were recognised in the red Type I fibres depending on the distribution of the final reaction product. The present histochemical evidence confirms the fact that subdivision of mammalian skeletal muscle into three fibre types is only approximate and probably more than three types exist.     

Further histochemical properties of rabbit skeletal muscle fibres

Summary The histochemical activities of succinic dehydrogenase (SDH), creatine kinase (CK), sarcoplasmic reticular ATPase (SR-ATPase) and myosin ATPase were studied in serial sections of rabbit adductor muscle. Three fibre types were distinguished depending upon the distribution of the enzyme activities. The type II white fibres posessing minimal SDH showed high myosin ATPase, SR-ATPase and ATPase dependent CK activities. Red oxidative fibres showing high SDH fell into two distinct groups: One category had mainly a peripheral localization of SDH and showed an enzymatic profile identical to that of type II white fibres. The second category of red fibres displayed both a homogeneous distribution of small diformazan granules throughout the fibre as well as a sub-sarcolemmal collection when tested for SDH activity but possessed very low amounts of reaction product of the various enzymes of the energetic metabolism studied. Since it is well established that the myosin ATPase of a fibre correlates with its contraction time, the present histochemical investigation provides further support for this concept by demonstrating the presence of high SR-ATPase and ATPase dependent CK activities in all white and red fibres rich in myosin ATPase.     

Diurnal variations in a shallow tropical freshwater fish pond in Shahjahanpur,U.P. (India)

Summary Diurnal variations in water chemistry and plankton in this eutrophic tropical freshwater ponds were quite apparent. Large fluctuations were noted in dissolved oxygen, pH, carbonate and bicarbonate concentrations. The pond water gets oversaturated with oxygen during day (24.2 p.p.m.) and depleted in the night (1.2 p.p.m.). Diurnal migrations of plankton were not in conformity with temperate waters.     

Rapid detection of 6-phosphogluconate dehydrogenase variants by electrophoresis on cellulose acetate gel

A procedure, suitable even under field conditions for the rapid detection of 6-phosphogluconate dehydrogenase electrophoretic variants, is described.Work supported by N.I.H.—grant no. ROI GM 13415.     

Photodynamic Inactivation of Antigenic Determinants of Single-Stranded DNA Bacteriophage φX174

Bacteriophage phiX174 when photodynamically inactivated (i.e., when rendered unable to produce plaques as a result of exposure to visible light in air in the presence of proflavine) progressively lost their capacity to bind efficiently with homologous antiserum. Such loss of serum-blocking power was evident with heat-inactivated but not with UV-irradiated phage. The ability of the phages to adsorb to host cells, however, remained practically unaltered even after photodynamic inactivation. It thus appears that photodynamic damages in the so-called "jacket" component of the phiX174 coat proteins are partly responsible for the loss of plaque-forming ability, whereas the "spikes" are either poor antigens or insensitive to photodynamic treatment.