Enzyme histochemical changes in murine osteoarthritis

Summary Male mice of the STR/ORT strain spontaneously develop an osteoarthritic lesion in the medial tibial condyles. Histochemical studies of lactate dehydrogenase have previously shown that a region of completely inactive chondrocytes develops in the cartilage prior to degenerative changes. The present studies have shown a nearly parallel time course for the development of inactive cells and cartilage damage, except that there is a delay of four to five weeks between these two events. It is considered that the latter is a consequence of the former. The mechanism of the enzyme depletion is not known, but it probably extends to many, if not all, oxidative enzymes, and it is suggested that a disturbance in a hydrogen transport (cytochrome) system could account for the apparent lack of activity of many dehydrogenases as demonstrated by tetrazolium salt techniques.     

Histological and histochemical techniques applied to the acaricales

Summary Schedules and technical methods in the preparation of permanently stained slides of members of the Agaricales are given. The results obtained from the examination of sections of members of the Bolbitiaceae and Boletaceae so prepared are discussed. The work described is that originally carried out by the late Dr.Max Barrett.     

Enzyme histochemical differentiation of white adipose tissue in the rat

Subcutaneous adipose tissues from fetal and young rats were studied with enzyme histochemical techniques. Lipid staining and histological evaluation were also utilized to compare the development of a wide variety of enzyme activities to cytoplasmic lipid deposition and morphological differentiation of adipocytes. Three distinct stages of adipose-tissue differentiation were postulated. In stage III, adipocytes were morphologically differentiated (rounded, basal-lamina positive) and enzyme reactive for many enzymes. In stage II, however, adipocytes were reactive for some enzymes but were not morphologically differentiated. Stage I adipose tissue was histologically distinct from connective tissue but did not contain lipid-laden cells or enzyme-reactive cells. Stages I and II (95%) were predominant in fetuses, whereas stage III (90%) was predominant in young animals. Histochemical analysis of adipocytes in newborn rats established the metabolic competence of these cells despite their small size. These studies indicate that enzymatic differentiation of adipocytes clearly precedes morphological differentiation.     

Enzyme histochemical studies on the pathological changes in human Sertoli cells

Two forms of human Sertoli cell disorders were characterized enzyme histochemically from the testicular biopsy material of infertile and subfertile patients. Sertoli cell asthenia: a slight injury of the Sertoli cell with exfoliation of individual germ cells; marked by the rarefaction of reaction zones of thiamine pyrophosphatase (TPPase) and a decrease in lactate dehydrogenase (LDH). Sertoli cell insufficiency: severe Sertoli cell damage with the formation of a "puff" and a heavy exfoliation of germ cells (dislocation of Sertoli cell nucleus and cytoplasm along with the related germ cells into the lumen of seminiferous tubule); marked by a heterogeneous activity pattern of TPPase, the disappearance of LDH, maintenance of a slightly weakened activity of alkaline phosphatase, and an increase of acid phosphatase. In the case of Sertoli-cell-only syndrome, the high prismatic Sertoli cells showed strong acid phosphatase activity with scattered weak TPPase reaction, whereas the flat or cube-like Sertoli cells exhibited weak acid phosphatase activity with only one small round reaction zone of TPPase in each cell. In addition, the frequency of the occurrence of Sertoli cell asthenia, Sertoli cell insufficiency, and Sertoli-cell-only syndrome is reported, and its correlation with the andrological diseases discussed.     

Enzyme histochemical studies on the conducting system of the human heart

Summary In this communication, the results of applying various histochemical techniques for the localization of oxidoreductases, transferases, hydrolases and isomerases in the human heart are presented. The Purkinje fibres of the atrioventricular conducting system of the human heart differ from the myocardium proper in containing a slightly higher activity of most of the glycolytic and gluconeogenetic enzymes investigated. The relatively higher activity of 6-phosphofructokinase, the key enzyme in anaerobic carbohydrate metabolism, is especially noteworthy. On the other hand, the activities of some of the enzymes that play a part in the aerobic energy metabolism is slightly less than those in the myocardium fibres.As for the activity of the NADPH regenerating enzymes, the activity of 6-phosphogluconate dehydrogenase and malate dehydrogenase (oxaloacetate-decarboxylating) is somewhat higher, and the activity of glucose-6-phosphate dehydrogenase similar, in the Purkinje fibres compared to that in the myocardial fibres. The activity of myosin ATPase is similar for both types of fibre. Likewise, the fibres of the conducting system and of the myocardium show a similar activity of acid phosphatase, -glucuronidase, non-specific naphthylesterase and peroxidase. The neurogenic function of the conducting system of the human heart was demonstrated by the high activity of acetylcholinesterase in the Purkinje fibres and in the atrioventricular node. All these histochemical findings in Purkinje fibres are similar at widely differing levels of the conducting system.     

Enzyme histochemical properties of kitten osteoclasts in bone imprint preparations

Synopsis The enzyme histochemical characteristics of osteoclasts in imprints of the metaphyseal regions of femurs, from male kittens aged approximately 18 weeks, were investigated. A selected number of enzymes representative of a variety of metabolic pathways were studied. The enzyme profile, time for the first appearance of detectable reaction product, intensity of the reactions, and localization of the reaction products were noted.Osteoclasts are rich in enzymes, and metabolic pathways are well developed in respect of the utilization of the reduced coenzymes NADP and NADPH, succinic, malic, lactic, and isocitric acids, -hydroxybutyrate and glucose-6-phosphate, the reactions being mediated by the diaphorases and dehydrogenases. The activities of acid and neutral phosphatases, non-specific esterases, and leucine naphthylamidase were high in these cells. However, little or no activity was demonstrated in respect of glutamate and -glycerophosphate dehydrogenases or of aryl sulphatase, glucose-6-phosphatase and alkaline phosphatase.     

Enzyme histochemical studies on rat amygdala in fetal alcohol syndrome

Histochemical studies were made of the activity of oxidative and hydrolytic enzymes in rat amygdala in FAS (Foetal Alcohol Syndrome). Ethanol in a dose of 9 g/kg/day was administered to rats during pregnancy and lactation in 6% aqueous solution as the only available liquid. The control rats received an equivalent diet in which ethanol was substituted by an equicaloric amount of sucrose. The offsprings were examined at the end of the 6th postnatal week. The activity of the lysosome and membrane enzymes, as well of some enzymes participating in the neurotransmission, was changed. A different decrease of the activity of oxidoreductases of Krebs cycle, glycolysis and pentose cycle was observed. The changes in the enzyme activity in the amygdala in FAS suggest alterations in the metabolism of the nervous tissue, rather than structural damages of cell organelles.