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Comparative study on peroxidatic activity in inflammatory cells on cutaneous and peritoneal implants
Abstract:
Inflammatory reactions were evoked by simultaneous implantation of pieces of Melinex plastic in the subcutaneous tissue of the dorsum and in the peritoneal cavity of rats. The cellular composition of the Melinex-adherent cells and their peroxidatic (PO) activity were investigated in relation to the duration of implantation. Several striking differences were found between the subcutaneous and peritoneal implants. On the 7th and 14th days, multinucleated giant cells were abundantly present on the subcutaneous implants, whereas they were relatively rare on the peritoneal implants. The subcutaneous implants bore no mast cells and only a few eosinophilic granulocytes, but both types of cell were observed frequently on the peritoneal implants. Macrophages and multinucleated giant cells on the subcutaneous implants show PO activity only in the granules are PO negative. On the peritoneal implants three types of macrophages can be dintinguished: exudate macrophages which have PO activity restricted to granules or are PO-negative; macrophages with PO activity in granules and both the rough endoplasmic reticulum (RER) and nuclear envelope; and resident macrophages with PO activity only in the RER and nuclear envelope. In addition, two types of multinucleated giant cells are found, one with and the other without PO activity in the RER and nuclear envelope. Multinucleated giant cells with PO activity in the RER and nuclear envelope as well as exudate macrophages with PO activity in the RER and nuclear envelope were mainly found 32 h and 3 days after implantation of the Melinex in the peritoneal cavity. These findings are discussed in the light of current knowledge of the PO activity in macrophages and multinucleated giant cells. It is concluded that the appearance of PO activity in the RER and nuclear envelope of exudate macrophages and multinucleated giant cells is in all probability a transient phenomenon, and that there is no objective evidence to support the opinion that exudate macrophages with PO activity in the RER and nuclear envelope are transitional cells between exudate and resident macrophages.
Insights
Subcutaneous implants showed more multinucleated giant cells, while peritoneal implants had more mast cells and eosinophils. Peroxidatic activity in macrophages and giant cells varied by location and duration, suggesting a transient phenomenon.
Area of Science:
- Biomaterials Science
- Immunology
- Cell Biology
Background:
- Implantation of foreign materials like Melinex plastic triggers inflammatory responses.
- The cellular reactions and characteristics of cells adhering to implants can differ based on anatomical location.
- Peroxidatic (PO) activity in macrophages and giant cells is a marker of cellular function and differentiation.
Purpose of the Study:
- To investigate the cellular composition and peroxidatic (PO) activity of cells adhering to Melinex implants.
- To compare inflammatory reactions in subcutaneous versus peritoneal tissues in rats.
- To explore the functional significance of PO activity in macrophages and multinucleated giant cells in response to biomaterials.
Main Methods:
- Rats were implanted with Melinex plastic in subcutaneous and peritoneal locations.
- Cellular adherence and morphology were analyzed at different time points (7th and 14th days).
- Peroxidatic (PO) activity was assessed in macrophages and multinucleated giant cells using microscopy.
Main Results:
- Subcutaneous implants showed abundant multinucleated giant cells, while peritoneal implants had more mast cells and eosinophils.
- PO activity patterns differed significantly between subcutaneous and peritoneal implants.
- Specific macrophage subtypes and multinucleated giant cells with PO activity in the rough endoplasmic reticulum (RER) and nuclear envelope were transiently observed in the peritoneal cavity.
Conclusions:
- The cellular response to Melinex implants varies between subcutaneous and peritoneal environments.
- The appearance of PO activity in the RER and nuclear envelope of certain macrophages and giant cells is likely a temporary event.
- There is no definitive evidence that exudate macrophages with PO activity in the RER and nuclear envelope represent transitional forms to resident macrophages.