Thermal acclimatory responses of salivary amylase of Periplaneta americana (Linn.)

Summary A differential thermal acclimatory response of salivary amylase is evident in P. americana-nymphs demonstrating a translational and males a rotational pattern, while females exhibit the translational cum rotational pattern (Prosser's type IV-D).     

Raffinose as reserve sugar inDysdercus koenigii—a biosynthesis confirmation by14C glucose

Summary Dysdercus koenigii, studied for its sugar spectrum, showed consistent absence of trehalose in its blood and body muscles. Instead of this known reserve sugar, raffinose has been shown to fulfil this need. The biosynthesis confirmation has been made by¹⁴C glucose.     

Biochemical effects of reperfusion after regional myocardial ischemia of different duration in the open chest dog]

Restoration of blood flow after 15 or 45 min. of ischemia induced an immediate recovery of phosphocreatine level and adenylate energy charge whereas ATP and total adenine nucleotides remained significantly below their normal values. These results prove that oxidative phosphorylations are not impaired but that a pool of myocardial adenine nucleotides is lost during ischemia which cannot be restored shortly after reperfusion. The significance of energy charge as a regulatory parameter in the myocardium is discussed.     

Structural characteristics and distribution of satellite cells along crayfish muscle fibers.

The distribution of satellite cells (sc) in long-sarcomere muscle fibers from the carpopod extensor muscle of the crayfish (Astacus fluviatilis) has been studied electron-microscopically. The sc are spindle-shaped and are oriented parallel to the long axis of a fiber. The mean lengths of sc nuclei (17.00 microns) and that of myonuclei (18.35 microns) differ non-significantly. In older animals, the mean ratio of the number of sc nuclei to the total number of nuclei (sc nuclei + myonuclei) is 0.0716, 0.0848, and 0.034 for the tendon, central and shell segments, respectively. The corresponding values for younger animals are 0.158, 0.166, and 0.081. The mean numbers of sc nuclei per mm of a fiber are 94, 117, and 47 (older animals), and 164, 117, and 94 (younger animals) for the tendon, central and shell segments, respectively. The high incidence of sc per unit fiber length in crayfish may be related to the fact that crayfish muscle fibers have a much larger diameter than vertebrate muscle cells.     

Spontaneous miniature potentials in primary afferent fibres

Summary Intracellular recording from primary afferent fibres of the isolated frog spinal cord revealed the existence of spontaneous synaptic activity, related probably to the firing of presynaptic inhibitory fibres.