Histological study of articular cartilage in experimental rat knee arthritis induced by intracapsular injection of cationic polyethyleneimine

Abstract

Degeneration of proteoglycans and abnormalities in their metabolism have been assumed to be critical at an early stage of osteoarthritis. To clarify a trigger mechanism of osteoarthritis, anionic sites of knee articular cartilage were blocked by intracapsular injection of cationic polyethyleneimine of 2000 or 70,000 molecular weight (MW) into rat knee joints. Experimental or normal rats were examined by gross observation, roentgenography, cytokine interleukin-1beta (IL-1beta) assay, and light or electron microscopy. In both groups with the polyethyleneimine injection, the rats showed temporarily limping and swelling of their knee joints. By light or electron microscopic studies, knee articular cartilage was found to be degenerated at an early stage, but IL-1beta was within normal levels. At 2, 4, or 6 months, the deformity of the knee joints was obvious by roentgenography. Degeneration and hypofunction of proteoglycans might be related to the ultrastructural changes of articular cartilage at an early stage, though the inflammatory cytokine was not involved. At later stages the pathophysiology of the knee joints advanced chronically to typical osteoarthritis, which was more radically induced by the large molecular polyethyleneimine (70,000 MW). The functional impairment of anionic sites is a key point for elucidating the mechanism of osteoarthritic development in this animal model.

Effect of GCSB-5, a Herbal Formulation, on Monosodium Iodoacetate-Induced Osteoarthritis in Rats

“…Seven and 28 days following MIA injection, rats were checked with roentgenography to assess chronic morphological changes of knee articular bones for narrowing, loss of joint region, cartilage erosion, and osteophyte formation [23]. For histological analysis, knee joints were removed and fixed in 10% neutral buffered formalin, decalcified with 10% formic acid, and embedded in paraffin.…”

Anti-Osteoarthritic Effects of a Mixture of Dried Pomegranate Concentrate Powder, Eucommiae Cortex, and Achyranthis Radix 5:4:1 (g/g) in a Surgically Induced Osteoarthritic Rabbit Model

“…X-ray images have been widely used to detect loss of cartilage erosion, joint region, and osteophyte formation during the development of OA [62,69]. Thus, anti-OA agents should inhibit cartilage damage on X-ray images to indicate efficacy [49,70].…”

Anti-osteoarthritic effects of a combination of pomegranate concentrate powder, Eucommiae cortex and Achyranthis radix in rats

“…An in vivo study 36) showed that a PCP:EC:AR ratio Physical injuries can cause the loss of a joint region, cartilage erosion and osteophyte formation. These changes can been observed by gross observation and X-ray images 37), 52) , and are considered a reasonable index for measuring the efficacy of anti-OA drugs 53), 54) .…”