ABSTRACT
O processo de criopreservação causa estresse físico e químico aos espermatozóides, acarretando alterações bioquímicas, diminuição irreverssível da motilidade espermática, aumento da degeneração do DNA e liberação intracelular de enzimas e lipídeos. No presente estudo, foram estudadas a influência das estações não reprodutiva e reprodutiva, dos crioprotetores glicerol e etilenoglicol e do processo de congelação e descongelação sobre o complexo DNA-proteína de espermatozóides em garanhões. Foi comparados o sêmen puro, o sêmen puro e congelado sem crioprotetores, o sêmen diluído e exposto aos crioprotetores sem congelação e o sêmen diluído e congelado com crioprotetores. Foram utilizados seis garanhões, colhendo 12 ejaculados cada. A patologia do complexo DNA-Proteína foi avaliada em espermatozóides fixados com etanol-ácido-acético glacial 3: 1 (v/ v), tratados com HCL 4N a 25°C e corados com azul de toluidina a 0,025% em tampão McIlvaine, empregando microscopia óptica com aumento de 1000x. Os resultados mostraram que a anomalia do complexo DNA-Proteína dos espermatozóides diferem entre os grupos congelados e não congelados (P<0,05). O sêmen congelado sem crioprotetor não apresentou aumento significativo de patologia do complexo DNA-Proteína em relação ao sêmen congelado com crioprotetores, mas ambos mostraram aumento em relação ao sêmen puro ou diluído e exposto aos crioprotetores. A influência da estação reprodutiva mostrou diferença significativa (P<0,05) somente no sêmen puro e no sêmen puro e congelado sem crioprotetor. Conclui-se que o processo de congelação exerce influência negativa sobre o complexo DNA-Proteína de espermatozóides em garanhões.
The cryopreservation process cause stress physical and chemical to the spermatozoa, causing biochemistry alteration, irreversible reduction of the spermatic motility, increase of the DNA degeneration and intracellular enzyme and lipids release. The aim of this study was to evaluate the influence of non-breeding and breeding seasons, glycerol and ethylene glycol, cryopreservation and thawing processes on stallion spermatozoa DN A -protein complexo It was compared fresh semen, diluted semen frozen without cryoprotectants, diluted semen exposured to cryoprotectants but not frozen and d) diluted semen frozen with cryoprotectants. Six stallions had 12 semen collections each. DNA-protein complex pathology was assessed by optical microscopy (1000x) using spermatozoa treated with ethanol-acetic acid 3:1 (v/v), HCl 4N at room temperature and toluidin blue 0,025% in McIlavaine buffer. Results showed that DNA-protein complex were different between frozen and not frozen spermatozoa groups (P<0,05). Frozen semen without cryoprotectants had no increasing of DNA-protein complex pathology compared to semen cryopreserved with cryoprotectant, but both showed increasing in relation to fresh and diluted semen exposured to cryoprotectants. The influence of non breeding and breeding season showed significant difference (P<0,05) in the fresh semen and fresh semen frozen without cryoprotectants. Cryopreservation process had negative influence on spermatozoa DNA-protein complex.
Subject(s)
Animals , Cryopreservation/methods , Horses , Semen Preservation/methods , Protamines/metabolismABSTRACT
OBJECTIVE: To compare embryo implantation in Wistar rats submitted to ovarian stimulation using recombinant FSH (rFSH) with cetrorelix acetate or leuprolide acetate. DESIGN: Experimental study. SETTING: Faculty of medicine animal facility. PATIENT(S): Fifty-six female Wistar rats with normal estrus cycles and 30 male. INTERVENTION(S): Ovarian stimulation and laparotomy (by the day 13 of gestation). MAIN OUTCOME MEASURE(S): Embryo implantation. RESULT(S): The female rats were subdivided into four groups: group 1, medicated with rFSH, hCG, and cetrorelix acetate; group 2, medicated with rFSH, hCG, and leuprolide acetate; group 3, medicated with rFSH and hCG; and group 4, in which only saline solution was administered. The female rats were mated with fertile male rats on the day of hCG administration with copulation confirmed through cytologic vaginal analysis. The females were killed on the 13th day of gestation. After laparotomy, comparison and identification was done regarding the numbers of corpora lutea and embryo implantations and gestation rates. Group 1 presented lower numbers of corpora lutea and embryo implantations in comparison to the other groups (P<.05). A difference was not found in the gestation rates between the groups. CONCLUSION(S): The number of embryo implantations in Wistar rats medicated with rFSH and cetrorelix acetate is lower than that of rats medicated with rFSH and leuprolide acetate.
