RESUMO
The peroxidase-oxidase reaction has become a model system for the study of oscillations and complex dynamics in biochemical systems. In the present paper we give an overview of previous experimental and theoretical studies of the peroxidase-oxidase reaction. Recent in vitro experiments have raised the question whether the reaction also exhibits oscillations and complex dynamics in vivo. To investigate this possibility further we have undertaken new experimental studies of the reaction, using horseradish extracts and phenols which are widely distributed in plants. The results are discussed in light of the occurrence and a possible functional role of oscillations and complex dynamics of the peroxidase-oxidase reaction in vivo.
RESUMO
The distribution of protein S100 in the canine mammary gland was studied, this substance having been described as specific for myoepithelial cells. Two immunohistochemical methods, peroxidase-anti-peroxidase complex (PAP) and alkaline phosphatase-anti-alkaline phosphatase complex (APAAP) were used on frozen sections of normal canine mammary gland. Both the myoepithelial and epithelial cells stained positively with PAP. With APAAP, staining was also seen in the controls, presumably because endogenous alkaline phosphatase was not blocked. As protein S100 was shown to be present both in myoepithelial and epithelial cells of the mammary gland, it was concluded that S100 is not a specific marker for myoepithelial cells.