A Lipolytic Enzyme in Reactive Histiocytes of Guinea Pigs With Experimental Encephalomyelitis

Abstract

A lipolytic enzyme has been demonstrated by means of a cytochemical technique and by direct chemical assay in granulomatous tissues of guinea pigs with encephalomyelitis and demyelinization resulting from the injection of an emulsion comprised of brain tissue and adjuvants, including Mycobacterium butyricum. Combined histologic and cytochemical studies showed that the lipolytic enzyme was present in the cytoplasm of a large proportion of the reactive histiocytes in the granulomatous tissue around the site of injection in the diseased animals, and that the enzyme-containing histiocytes were even more numerous in the inflamed regional lymph nodes. In control experiments, when emulsions lacking either brain tissue or M. butyricum were injected in previously normal guinea pigs, the experimental condition did not develop; under these circumstances the lipolytic enzyme was found in only a small proportion of the cells of the granulomatous tissue around the injection sites, and it was almost negligible in the regional lymph nodes of these animals. It was absent from the cells of the lymph nodes of normal animals, and from the cells of talcum and aluminum hydroxide granulomas produced experimentally in guinea pigs. The lipolytic enzyme may be a factor in the pathogenesis of the experimental encephalomyelitis and demyelinization.

Studies on the Interaction Between Phagocytes and Tubercle Bacilli

“…Subsequently, individual cnzymc systems have been examined and found to differ in the normal and infected host. For example, enzymes such as phosphatases were found to be increased in the tuberculous granuloma (15,17) and the tissues themselves showed higher activity. Recently the succinic dehydrogenase activity of tissues from normal, infected and sensitized guinea pigs was measured.…”

Metabolic Profiling of Lung Granuloma in Mycobacterium tuberculosis Infected Guinea Pigs: Ex vivo 1H Magic Angle Spinning NMR Studies

“…A hypothesis is that these changes could be due to the degradation and remodelling of phospholipids (Figure 5A) by lipolytic phospholipases induced during the formation of granuloma. 41 Lung surfactants may be hydrolyzed by phospholipases, resulting in the formation of hydrolyzed products like free fatty acids, GPC, PC, Cho, and glycerol. It has been shown that TNF-R released during infection stimulates the rate of lipolysis.…”

Histochemistry of Leukocytes

“…(lc) 5-Nucleotidase: The existence of a specific enzyme, 5-nucleotidase, form. 44,64,66 capable of hydrolyzing nucleotides, for instance muscle adenylic acid, which contain phosphate esterified at carbon 5 of ribose has been first reported by Reis in various tissue extracts by chemical estimation.6' Its optimal activity is around a pH of 8. It can be demonstrated with a similar technique as nonspecific alkaline phosphatase, using muscle adenylic acid as substrate.23-62 A nucleotidase which, however, has its pH optimum at pH 4 has been reported to occur in leukocytes on chemical estimation.…”

“…Recently, Rutenburg and Seligman have introduced a new substrate, 6-benzoyl-2-naphthyl phosphate, with which sites of activity are stained very brilliantly. 66 In films from blood and bone marrow, stained with the lead phosphate method, there is seen a moderate cytoplasmic and very distinct nuclear reaction in all cells of the red and white 68 A positive reaction, in addition, was noticed in occasional neutrophilic granules and regularly in eosinophilic granules. Mast cells also react positive.59 There is some doubt whether nuclear staining with the lead technique indicates enzymatic activity or is due to staining artefacts.…”