Dehydrogenase histochemistry of the rat molar pulp

Membrane junctions in the subodontoblastic region. A freeze-fracture study of the human dental pulp

The morphology of the subodontoblastic region in the human dental pulp was analysed using the freeze-fracturing technique. Multiple areas of focal intercellular junctions were found between subodontoblastic fibroblasts (or Höhl's cells). The connections were of the gap junction type. Similar junctions were observed between subodontoblastic cells and small-calibre (0.10-0.20 microns) fibres, presumably nerves. Tight junctions were not observed.

Metabolic activity of deciduous porcine dental pulp in different phases of root development

The present investigation examined the activities of various enzymes associated with the carbohydrate metabolism in different phases of root development of swine deciduous dental pulps. The data showed that the potential carbohydrate metabolizing capacity of pulpal tissue was greatest in the root forming phase (two months). However, when compared with samples taken from the fully formed root (six months), a higher activity of glucose-6-phosphate dehydrogenase and lactate dehydrogenase was found in samples taken from the root resorption phase (nine months).

Succinate dehydrogenase activity in the developing molar of the hairless mouse Mus musculus

Succinate dehydrogenase activity in the odontogenic tissues of the hairless mouse (hr/hr) has been studied from the initiation of the dental lamina through apposition. Enzyme activities were designated as negative, slight, moderate and strong as a function of intensity of the reaction product. Enzyme levels in the odontogenic tissues increased with advancing tooth morphogenesis. Greatest activity was observed in the ameloblastic layer which peaked on the fourth to sixth postnatal days. This cell layer displayed higher enzyme activity than the ectomesenchymally-derived odontoblasts. Succinate dehydrogenase activity appeared to be related to the degree of differentiation and functional competence on the odontogenic tissues of the hairless mouse.

The turnover of collagen in the dental pulp of rat incisors

The turnover of collagen in the dental pulp was studied using H3-proline and microchemical techniques. The incorporation of label into the whole tissue was very high, with most of the label being incorporated into the noncollagenous substances. The rate of disappearance of label from collagen approximated the disappearance of label from noncollagenous components, suggesting that the whole pulp was undergoing rapid remodeling. There seems to be more than one metabolic pool of collagen.

Succinate dehydrogenase activity in the developing molar of the Mongolian gerbil Meriones unguiculatus

The distribution of succinate dehydrogenase in the odontogenic tissues in the Mongolian gerbil, ranging in age from 18 days prenatal to 8 days postnatal, was studied. Activity levels were designated negative, trace, slight, moderate, strong and very, dependent upon visual observations. The results indicated increased levels of activity as the tissue layers differentiated from the lamina stage through early apposition. The cell layer displaying the most succinate dehydrogenase activity was the ameloblastic layer while the stratum intermedium layer was the next most active cell layer. Succinate dehydrogenase activity appeared to be related to the degree of differentiation and functional competency of the odontogenic tissues in the Mongolian gerbil.