Efeito do γ-Oryzanol na degeneração testicular induzida por insulação escrotal em carneiros

Abstract

Factors affecting reproductive fertility have a low pregnancy rate and negatively affect herd productivity and profitability. The increase in testicular temperature is a causative effect of testicular degeneration and consequent failure in quality and seminal production in sheep. Among the mechanisms related to testicular damage is the oxidative stress. -oryzanol is a component of rice bran oil, which has been described as a potent antioxidant, and also demonstrates significant improvements when tested at the level of the male reproductive system. In this context, this study aimed to evaluate the effects of supplementation with 33mg / PM / day of y-oryzanol in the face of testicular degeneration induced by scrotal insulation in sheep. For this, eight rams were used, which were divided into 2 groups: Control (submitted to scrotal insulation without treatment) and Gamma (submitted to scrotal insulation and γ- oryzanol treatment). The sheep were subjected to scrotal insulation induced by thermal bag placement for 72 hours. Gamma animals received 33 mg / MW oral y-oryzanol once daily, starting 7 days before insulation, during insulation and 20 days after insulation, totaling 30 days of treatment. Samples of blood and semen were collected during the experiment for biochemical evaluations related to oxidative stress, membrane integrity, motility and seminal morphology, as well as plasma testosterone dosage. Ultrasound examinations of the testicular parenchyma and clinical evaluations of consistency and scrotal perimeter were performed with weekly interval. Testicular tissue collections for biochemical analysis of oxidative stress were performed at the end of the experiment by orchiectomy. The results indicated the occurrence of testicular degeneration induced by scrotal insulation, as demonstrated by the reduction of the scrotal perimeter and increase in testicular flaccidity immediately after insult, as well as the late increase of hyperechoic points in the parenchyma by ultrasonography and reduction of motility in the 10th week. Treatment with γ-oryzanol reduced ROS in the testis, increased FRAP by the 10th week, increased TBARS, maintained a higher number of intact spermatozoa at week 3, but increased total defects from week 5 onwards. Although γ-oryzanol showed protection in part in the oxidative parameters evaluated in the semen and testis, this therapy did not improve other parameters studied. In addition, supplementation with γ- oryzanol caused a higher number of total morphological abnormalities in semen. The present study shares unpublished information on the use of γ-oryzanol oral in rams with testicular degeneration, in the intention of therapies for this pathology so important in the system of production and that still does not have established treatment.