Combined effects of ovariectomy and streptozotocin-induced diabetes in the articular cartilage of rats.

AIM: To evaluate the combined effects of streptozotocin-induced diabetes (Di) and ovariectomy in the articular cartilage of rats. METHODS: Forty adult female Wistar rats were ovariectomized (OVX) or sham-operated. After recovery from surgery, the animals were assigned randomly into four groups: OVX control (OVX-C); OVX treated with 10 µg/kg/day of 17ß-estradiol (OVX-E); sham-operated subjected to Di (Sham-Di); and OVX subjected to Di (OVX-Di). After 60 days of treatment, the animals were euthanized and the distal femurs with articular cartilage were processed for paraffin-embedding. Sections were stained with hematoxylin and eosin for histomorphometry, Picro-Sirius Red for collagen, or Alcian Blue for glycosaminoglycan (GAG) content. To detect apoptosis, sections were stained with an antibody to cleaved caspase-3 (casp-3). RESULTS: Articular cartilage thickness and GAG content were significantly lower (p < 0.05) in the OVX-Di group, which also showed a higher number of casp-3-positive chondrocytes than the other groups. Interestingly, the higher percentage (p < 0.05) of mature collagen fibers was seen in the OVX-Di group, may be as a result of a reduced extracellular matrix remodeling of the articular cartilage. CONCLUSION: Our results indicate that the combination of ovariectomy and streptozotocin-induced diabetes produces more deleterious effects in articular cartilage of rats than either condition alone.

Effects of soy isoflavones on the concentration of hyaluronic acid in the vagina of type 1 diabetic rats.

OBJECTIVE: To assess the effects of isoflavones and 17ß-estradiol on the vaginal epithelium extracellular matrix and hyaluronic acid (HA) in the diabetic rat model. METHODS: Sixty adult, virgin, female rats underwent ovariectomy, then randomization into six groups of ten animals each: GI, sham ovariectomized control animals; GII, sham ovariectomized control diabetic animals; GIII, control ovariectomized rats receiving propylene glycol vehicle; GIV, control ovariectomized diabetic animals receiving propylene glycol vehicle; GV, diabetic ovariectomized animals treated with soy isoflavones (150 mg/kg by gavage); GVI, ovariectomized diabetic rats treated with estrogen (17ß-estradiol, 10 mg/kg, subcutaneously). Treatment took place over 30 consecutive days. After euthanasia, a portion of the vagina was immersed in liquid nitrogen for RT-qPCR and Western blotting. Another portion was processed for paraffin embedding. Sections were stained with hematoxylin & eosin for histomorphometry and Picro Sirius Red for collagen quantification. RESULTS: Vaginal epithelium histomorphometry in GIII (15.3 ± 1.1 µm) and GIV (14.5 ± 1.8 µm) was thinner than in GV (41.3 ± 1.5 µm) and GVI (74.3 ± 1.6 µm). There was an increase in collagen content in GV (84.1 ± 1.2 µm) and GVI (88.2 ± 1.7 µm). HA quantification was higher in GV (0.38 ± 1.1 µg/mg) and GVI (0.49 ± 1.4 µg/mg) when compared with GIII (0.12 ± 1.1 µg/mg) and GIV (0.10 ± 1.2 µg/mg), p < 0.05. CONCLUSIONS: Soy isoflavones increase hyaluronic acid concentration in the vagina of diabetic ovariectomized rats. Such findings might help to attenuate the effects of vulvovaginal atrophy in women.