The advantages of low-density lipoproteins in the cryopreservation of bull semen.

Egg low-density lipoprotein (LDL) was added at concentrations (w/v) of 7%, 8% or 9% to the extenders used to freeze bull semen and its effects on seminal parameters and anti-oxidant activities of frozen-thawed sperm were assessed. Analysis of data showed that sperm exposed to 8% LDL exhibited the greatest percentages of sperm motility, acrosome integrity and membrane integrity, compared to the control which differed from the treatment groups by replacing LDL with 20% egg yolk (P<0.05). No difference was observed for membrane integrity between 8% and 9% LDL groups (P>0.05). The extender supplemented with LDL did not exhibit improvement in SOD levels. However, 8% LDL group favored the highest anti-oxidant activities of CAT, GSH-Px and GSH in comparison to other groups (7%, 9% LDL and the control) (P<0.05). No difference was observed for CAT activity between 9% LDL and the control group. In conclusion, sperm cryopreserved in the extender containing 8% LDL in place of egg yolk exhibited the greatest percentages of post-thaw sperm motility, acrosome integrity and membrane integrity, in comparison with the control, and favored the highest anti-oxidant activities of CAT, GSH-Px and GSH in comparison with other groups. The replacement of egg yolk by LDL in the composition of extenders was beneficial for bull sperm cryopreservation.

Aorta wall quantitative alterations due to different long-term high-fat diet in rats.

Twenty Wistar male rats, with ages varying from 21 days to 12 months, were fed with diets supplemented by soybean oil (S group), canola oil (CA group), lard and egg yolk (LE group), and canola plus lard and egg yolk (CA+LE group). The LE group presented the highest heart mass/body mass ratio and the highest blood pressure as well. The aortic structure suffered a number of alterations, from CA rats group (minor alterations) to LE and CA+LE rats group (major alterations). The CA group showed the smallest aorta thickness. No significant differences among groups were found concerning the number of aortic lamellae and the density of tunica media smooth muscle nuclei. Surface density of the aortic lamellae was greater in the CA group and smaller in the LE group. These results suggest that the dietary intake of canola oil could attenuate the aorta structure aging process with a favorable BP maintenance.