effect of d-glucosamine sulfate on temporomandibular joint antigen induced arthritis in albino rats [histological, histocheniic and digital image analysis]

The purpose of this study was to evaluate the effects of d-glucosamine sulfate on tem-poromandibular joint arthritis. The present study was carried out on ninety male albino rats of average weight [150 - 20gmO]. These rats were divided into control healthy, arthritic arthritic nontreated and treated groups. Thirty rats for control and sacrificed parallel with group II and, III, thirty rats for group II [arthritic nontreated] which subdivided into three equal subgroup A, B,C they were sacrificed after arthritis induction by thirty, sixty, ninety days respectively and thirty rats for group III [treated group] which subdivided into three equal subgroups D, E, F. they were sacrificed after thirty, sixty and ninety days of treatment of arthritis respectively. The specimens were taken, fixed, demineralized and processed for paraffin sections. The sections were studied histologically, his-tochemically, statistically and digital image analysis.The results of this study, histologically; in group II there were side adhesion between the articular cartilage and the disc, thinning and irregularities of some parts of articular cartilage and destruction of subchondoral bone. These criteria decreased in severity from subgroup A to C. but in group III all these criteria in group II regenerated gradually from subgroup D to F which appeared nearly normal at subgroup F. Histochemically; in group II the collagen fibers were decreased and disarranged with matrix defect and loss of toludine blue stain, intense reaction to acid phosphatase, mild reaction to alkaline phosphatase. In group III the collagen fibers and matrix regenerated gradually from D to F after the treatment, very weak reaction to acid phosphatase and intense reaction to alkaline phosphatase. Digital image analysis revealed that the net collagen matrix was increased in group III more than group II. statistical analysis, there was significant increase in cartilage thickness and collagen matrix in group III more than group II.Based on the previous results we conclude that, treatment of temporomandibular joint arthritis by d-glucosamine sulfate leads to decrease the degenerative changes of osteoarthiritis in the joint, increases collagen formation, enhances the matrix formation and reduce the osteoarthritic pain. This paper was extracted from a thesis submitted in partial fulfillment for master degree in oral biology by rehab r elzehery [demonstrator in oral biology, faculty of dentistry, man-soura university]

Effect of angiotensin-converting enzyme inhibitors, captopril and lisinopril, on collagen synthesis by cultured rat liver cells

Several studies have documented the role of angiotensin-converting enzyme inhibitors [ACEI] as antifibrogenic and antiproliferative in different tissues in vivo and in vitro but unfortunately non of them has investigated this effect on collagen synthesis by individual liver cells. In this study we focused on the in vitro effect of two ACEI with different pharmacologic properties, captopril and lisinopril, on the synthesis of types I and III collagens by individual liver cells, since these types of collagens are the most abundant ECM molecules both in normal and fibrotic liver. Rat liver cells were isolated, separated according to cell types through density gradient centrifugation in percoll then cultured as separate clones for 24 hours. Types I and III collagens secretion was measured by gel electrophoresis [SDS-PAGE] and computer analysis of their alpha chains after purification from cell culture media. Both captopril and lisinopril significantly reduced types I and III collagens by cultured hepatocytes [HC], liver endothelial cells [EC], and hepatic stellate cells [HSC] with more prominent action for captopril than lisinopril. The present study document the inhibitory effect of ACEI on types I and III collagen synthesis by liver cell sub-population in vitro by a mechanism independent on the systemic angiotensin-converting enzyme inhibition and possibly through a mechanism involving a local renin-angiotensin system or interference with intracellular events involved in collagen synthesis

effects of melatonin administration on some endocrine functions in rats

This study was conducted to investigate the effects of chronic oral melatonin administration in dose of 0.4 mg/kg B.W. daily for 30 days on serum TSH, T4, FSH, LH and insulin. 160 albino rats of both sexes were used, they were grouped into 16 groups, of which 8 groups were used to investigate the endocrinal effects of melatonin in both light and dark conditions. The other 8 groups were used for the same investigations under stressful condition in both light and dark as well. Half of all these groups were served as placebo controls. It was concluded that exogenous melatonin is recommended only as replacement therapy for persons sleeping in light to avoid disturbance of thyroid function especially in hyperthyroid patients. Also, melatonin has no role in counteracting the effects of acute stress on the endocrine functions related to TSH, T4, LH, FSH and insulin