Comparative histochemical localization of lysosomal enzymes in rat tissues

Localization of acid phosphatase, β-glucuronidase and N-acetyl-β-glucosaminidase has been studied in various tissues of the rat with comparable simultaneous coupling azo dye techniques employing naphthol AS-BI compounds as substrates and hexazonium pararosanilin as a capture reagent. These three lysosomal hydrolases were widely distributed in tissues and were generally demonstrated as discrete granules in certain portions of the cytoplasm. Granules stained for each enzyme were localized at identical sites in most, but not all, tissues in which they were present. However, the intensity or number of granules stained for each of the enzymes was found to differ in varying degree among tissues. Acid phosphatase appeared to be more widespread in tissues than the two glycosidases. Distribution of the glycosidases was also found to differ considerably. Cells of the macrophage system, for example, displayed high β-glucuronidase activity, while N-acetyl-β-glucosaminidase was much less active in these cells. The latter enzyme was more active in the epithelium of the mucous membrane. Furthermore, in several tissues, the three enzymes exhibited qualitatively different localization. In these sites, one or two of the enzymes were not or were only faintly demonstrable while the other showed an intense reaction. These findings suggest that a functional differentiation among lysosomes in various tissues may exist.

Allomorphic forms of bacteriophage phiX-174 replicative DNA

The bacteriophage øX-174 replicative form of DNA exists in two configurations, as judged by electron microscopy and sucrose density gradient sedimentation, and on methylated albumin-coated kieselguhr column chromatography. The predominant 21S form of the DNA is a tightly twisted circle. Treatment with deoxyribonuclease causes a single scission in one of the two strands, resulting in an open circle which sediments at 16S.

Dieldrin: interaction with nerve components of cockroaches

We have evidence that the nerve components of the dieldrin-resistant German cockroach have less binding capacity for dieldrin than those of the susceptible cockroach; the highest interstrain difference was in the crudenucleus fraction. The dieldrin-nerve complexes are not extracted by many organic solvents.

An improved method of fixation for formalin-sensitive enzymes with special reference to myosin adenosine triphosphatase

Studies have been made on the effect of fixatives containing substrate and other additives on the histochemical staining reaction for myosin adenosine triphosphatase activity in the leg muscle, and α-glycerophosphate and succinate dehydrogenase activities in the kidney of the rat. Myosin adenosine triphosphatase was well preserved in the presence of adenosine triphosphate in fixative prepared from methanol-free formaldehyde and buffered to pH 7.2 with cacodylate. Addition of sucrose was found to increase the enzyme preservation. Similar protection of the enzyme activity was afforded by other polyphosphates, particularly sodium pyrophosphate and, to less degree, thiamine pyrophosphate, adenosine diphosphate and uridine triphosphate. α-Glycerophosphate dehydrogenase was also preserved to greater degree by a similar fixative containing α-glycerophosphate than by substrate-free fixative. Succinate dehydrogenase was not significantly preserved in succinate-containing fixative. On the other hand, sucrose in the fixative increased the preservation of succinate dehydrogenase but had no appreciable effect on α-glycerophosphate dehydrogenase.