Effect of calcitonin on experimentally induced osteoarthritis in adult male rabbits: biochemical, histomorphometric, and immunohistochemical study

Osteoarthritis [OA] is the most common joint disease. This disease progresses slowly and develops over years. Conservative treatment regimens for OA treat the symptoms but not the disease. The purpose of this study was to investigate the role of salmon calcitonin in the changes that occur in the articular cartilage and subchondral bone following experimentally induced OA in rabbits. Thirty adult male New Zealand white rabbits were used. They were divided into three groups: control; osteoarthitic; and calcitonin-prophylactic. On sacrifice, blood samples were withdrawn to estimate serum alkaline phosphatase, calcium, and phosphorus levels. Articular cartilage and subchondral bone were processed for histological, immunohistochemical, and morphometric studies. Estimation of bone calcium and phosphorous concentrations was also carried out. Articular cartilage of osteoarthritic rabbits showed a disrupted articular surface with a reduction of the subchondral bone thickness. An irregular or a doubled tide-mark was also seen. There was a change in the normal distribution of the chondrocytes with loss of the superficial layer. Weak Periodic Acid Schiff's and Alcian blue staining with a negative BCL-2 reaction were also present in the articular cartilage. Bone calcium and phosphorus concentrations were significantly decreased in OA compared with those of the control group. Serum alkaline phosphatase level was significantly increased in the OA group compared with the control group. In the calcitonin-prophylactic group, there was an improvement in biochemical, histological, and immunohistochemical changes. Calcitonin had a protective effect on the OA changes induced in the articular cartilage of rabbits. Also, it played a role in improving bone calcium and phosphorus content and integrity of the bone matrix

Effect of diltiazem on the changes induced by monosodium glutamate in the ovary of adult rats: histological and immunohistochemical study

Monosodium glutamate [MSG] is a popular taste enhancer that is used widely. It has been reported that MSG is toxic to human and experimental animals. To investigate the histological and immunohistochemical effects of MSG on the ovary and to study the possible role of diltiazem [L-calcium channel blocker] in the prevention of these effects in adult female rats. Thirty adult female albino rats were used and divided into three groups: control; treated; and prophylactic. The control group received fixed amounts of grower's marsh without adding MSG daily for 14 days. The treated group was given 6 g of MSG daily thoroughly mixed with equal amount of feeds [grower's marsh] for 14 days. In addition to MSG, the prophylactic group was given diltiazem daily dissolved in water by an oro-gastric tube [5 mg/g body weight] for 14 days. The rats were sacrificed on day 15 of the experiment. The ovaries were processed for histological and immunohistochemical reaction for induced nitric oxide synthase. The ovary of the MSG-treated group had some atretic follicles and vacuolated stromal cells arranged in clusters. The other types of follicles were distorted, showing a degenerated oocyte surrounded by disorganized cells of follicular granulosa cells with darkly stained nuclei and vacuolated theca folliculi cells. There was a significant decrease in the number of ovarian follicles and a significant increase in the optical density of induced nitric oxide synthase reaction in the treated group compared with the control group. In the diltiazem-prophylactic group, there was an improvement in the histological and immunohistochemical changes. Diltiazem had a protective effect on the histological and immunohistochemical changes caused by MSG toxicity in the ovary of adult rats

Histological study of the effect of exogenous glucocorticoids on the testis of prepubertal albino rat

Corticosteroids are potent medications that have been extensively used to treat many inflammatory and autoimmune conditions. To study the histological changes that may occur in the prepubertal albino rat testis after administration of dexamethasone and to investigate the possibility of recovery of testis after drug stoppage. Thirty prepubertal male albino rats were used and divided into three equal groups. Group I [control] and group II [dexamethasone-treated] that were injected daily intraperitonealy by dexamethasone [7mg/kg body weight] for 2 weeks. Group III [recovery] were injected daily intraperitonealy with the same dose of dexamethasone for 2 weeks as group II, then left untreated for further 2 weeks. At the time of sacrifice, the testes of all groups were dissected out, processed and stained with H and E. Semithin sections were stained with toluidine blue and ultrathin sections were examined by electron microscope. Histological examination of dexamethasone-treated rats revealed changes in most of the seminiferous tubules. They had lost the normal distribution of their epithelial lining with appearance of several layers of dark type spermatogonia. They were ensheathed by irregular basement membrane. Ultrastructurally, spermatogonia had small irregular nuclei with condensation of heterochromatin and their cytoplasm contained few mitochondria. Some primary spermatocytes showed clumps of heterochromatin in their nuclei and their cytoplasm contained few mitochondria. Other cells were apoptotic. Multiple Sertoli cells appeared with indented nuclei and peripheral marginated heterochromatin. Their cytoplasm showed mitochondria with disrupted cristae. Leydig cells appeared with irregular shaped nuclei, contained large heterochromatic masses and their cytoplasm had some electron dense bodies of variable sizes and shapes. The testis of recovery group contained distorted seminiferous tubules with no return to the normal histological structure. The present work showed that dexamethasone injection for 2 weeks produced destructive effects on the structure of prepubertal albino rat testes. Also, this work showed incomplete recovery of these effects after drug stoppage. In clinical practice, therapeutic doses of dexamethasone and periods of administrations must be carefully adjusted specially in younger ages