Morphological study on the effects of sample size on ovarian tissue vitrification.

OBJECTIVE: The present study aimed to assess the effects of ovarian cortex sample size on tissue morphological integrity after vitrification in a metal capsule. METHODS: Bovine ovarian tissue samples cut in large and small fragments (1x1x5 and 1x1x3 mm, respectively - 5 and 3 mm refer to length), vitrified in a metal capsule were fixed for histological analysis immediately after rewarming or after 48 hours culture. We assessed primordial, primary and secondary follicle morphology and stromal integrity. RESULTS: Primordial follicles showed the highest rates of normal morphology after rewarming and after 48 hours culture in both, small and large tissue fragments. Primary follicles presented a significant drop in normal morphology in large samples, after 48 hours in culture. Stromal integrity was well-preserved immediately after rewarming in small and large fragments but presented a significant drop in normal morphology in large samples, after 48 hours in culture. CONCLUSIONS: The ovarian reserve, represented by Primordial follicles, is well-preserved in small or large fragments, after vitrification and culture. However, the stromal components present better preservation after vitrification\rewarming, when tissue samples are cut in small fragments. Thus, small cortex samples should be preferred for ovarian tissue vitrification.

The influence of a diet based on flaxseed, an omega-3 source, during different developmental periods, on the blood pressure of rats submitted to stress.

OBJECTIVE: This study aimed to investigate a flaxseed diet during different developmental periods, and its effect on the blood pressure of rats submitted to stress. METHODS: Fifty-six male rats (F1), born from 14 rats (F0), were divided into seven groups (n = 8): flaxseed group (FG); flaxseed group gestation and lactation (FG-GL); flaxseed group weaning (FG-W); flaxseed group weaning and stress (FG-WS); flaxseed group stress (FG-S); flaxseed group gestation lactation and weaning (FG-GLW), and control Group (CG). Stress protocol was undertaken for 1 month. Blood pressure was analysed before and after the stress protocol. The left adrenal glands and serum corticosterone levels were analysed. RESULTS: Systolic blood pressure before stress was lower in all groups with flaxseed diet compared with the CG (p = .00001). After stress, CG showed higher blood pressure compared with FG, FG-GL, and FG-GLW (p = .004). The levels of corticosterone were lower in the FG between all groups (p < .000001) and the CG showed higher compared with FG-W, FG-WS, FG-GL, and FG-GLW (p < .0001). The adrenal gland did not show differences. CONCLUSIONS: Results suggest a possible factor from a flaxseed diet against the effects of stress on a blood pressure in all periods of life but especially in the gestation and lactation periods.

Antioxidant defense capacity of ovarian tissue after vitrification in a metal closed system.

OBJECTIVE: The present study analyzed the quality of bovine ovarian tissue after vitrification in a metal closed chamber, in terms of putative changes in tissue viability (lactate dehydrogenase -LDH- release), anti-oxidant defenses, and redox parameters caused by cryopreservation. METHODS: Small and large fragmented bovine ovarian tissue specimens were vitrified in a metal chamber. After rewarming, tissue samples were fixed or cultured for 48 hours. Glutathione (GSH), protein sulfhydryl content, Total Radical Trapping Antioxidant Potential (TRAP), and lactate dehydrogenase were analyzed immediately after rewarming and after tissue culture. RESULTS: No changes in antioxidant parameters or viability of rewarmed tissue samples were found immediately or 48h after vitrification. The method of vitrification in a metal closed chamber used in this study preserved the quality of bovine ovarian tissue. Furthermore, our data showed that the size of the tissue specimens did not affect post-vitrification biochemical viability parameters. CONCLUSIONS: We believe that the vitrification methodology employed in the present study is safe and effective, and should be evaluated for use in humans.

Flaxseed flour, compared to flaxseed oil, contributes to femoral structure in male rats subjected to early weaning.

The aim of this study was to analyze whether flaxseed flour or flaxseed oil treatment contributes to femoral structure in male rats subjected to early weaning. Pups were weaned for separation from mothers at 14 days (early weaning, EW) or 21 days (control, C). After 21 days, the control (C60) was fed with the control diet. The EW group was divided based on control (EWC60), flaxseed flour (EWFF60) and flaxseed oil (EWFO60) diets until 60 days. Femoral dimension, bone mineral density (BMD), bone mineral content (BMC), area and biomechanical properties were determined. EWFO60 showed lower (P < 0.05) femur mass. EWC60 and EWFO60 showed lower (P < 0.05) distance between epiphyses, diaphysis width and BMD. BMC was lower (P < 0.05) in EWC60 (vs. C60 and EWFF60). EWC60 and EWFO60 showed lower (P < 0.05) maximum force (vs. C60). Breaking strength was lower (P < 0.05) in EWFO60 (vs. C60). EWFF60 showed higher (P < 0.05) rigidity. Flaxseed flour abbreviated the femoral fragility secondary to early weaning.