ABSTRACT
Cryopreservation and transplantation of ovarian tissue are proposed methods for the restoration of endocrine function and reproductive potential. Therefore, this study aimed to evaluate the effects of vitrification and xenotransplantation on follicle viability, activation, stromal cell integrity, vascularization, and micronuclei formation. Bovine fetal ovaries were fragmented and assigned to the following groups: Fresh control (FC), ovarian fragments immediately fixed; Vitrified control (VC), ovarian fragments vitrified; Vitrified xenotransplanted (VX), ovarian fragments vitrified and xenotransplanted; and Fresh xenotransplanted (FX), ovarian fragments xenotransplanted. Ovarian fragments were grafted in female BALB/c mice and recovered after 14 days. Follicular viability was preserved (P > 0.05) in VC group. The rate of developing follicles was greater (P < 0.05) in the FX group compared to other groups. Follicular density was higher (P < 0.05) in the VC group than the FC, VX, and FX groups. A decrease (P < 0.05) of stromal cell density was recorded after vitrification (VC vs. FX). Blood vessel density decreased in VC, VX, and FX groups compared with the FC group, and blood vessel density was correlated with follicular viability (positively; P = 0.07) and developing follicles (negatively; P < 0.001). Both vitrification and xenotransplantation groups (VC, VX, and FX) had a greater (P < 0.05) number of cells with one MN compared to the FC group. In summary, our findings showed that both vitrification and xenotransplantation modified blood vessel, follicular and stromal cell densities, follicular viability and activation, and micronuclei formation in ovarian tissue.
Subject(s)
Cryopreservation/veterinary , Ovary/physiology , Tissue Preservation/veterinary , Transplantation, Heterologous/veterinary , Animals , Cattle , Female , Fetus , Mice , Mice, Inbred BALB C , Pregnancy , Tissue Preservation/methods , VitrificationABSTRACT
ABSTRACT: In a rural property of the Midwestern Minas Gerais, Brazil, three 2.5 to 3-year-old female bovines (7/8 Holstein x 1/8 Gir) weighing approximately 380kg died after showing brownish colored mucosa of conjunctiva and vaginal vestibule, gray-bluish tongue, dyspnea, sialorrhea, tympany, and progression to sternal decubitus and death. In the macroscopic evaluation of one of the bovines, dark (chocolate-colored) blood of difficult coagulation, and intensely cherry-red skeletal and cardiac musculature were observed. Beyond that were observed brownish lungs, kidneys, liver, and encephalon, and all the stomach compartments were dilated due to large amounts of gas. In addition, the carcass exhaled a nitrous odor. The diphenylamine test and the nitrate dosage in the forage (Pennisetum purpureum, "elephant grass", Napier grass cultivar) used in feeding the bovines showed a high concentration of nitrate, allowing the diagnosis of nitrate/nitrite intoxication. The main factors leading to the poisoning were attributed to excessive fertilization of grass with bovine manure, the occurrence of a drought period followed by a rainy season, lack of adaptation of the bovines to a nitrate-rich diet, and a diet composed almost exclusively of elephant grass. This is the first report of spontaneous nitrate/nitrite poisoning in cattle in southeastern Brazil.
RESUMO: Em uma propriedade rural do Centro-Oeste de Minas Gerais, três fêmeas bovinas 7/8 Holandês e 1/8 Gir, com idade de 2 anos e 6 meses a 3 anos e peso de aproximadamente 380kg vieram a óbito após manifestação clínica de mucosas conjuntivais e do vestíbulo vaginal amarronzadas, língua azul-acinzentada, dispneia, sialorreia, timpanismo e progressão para decúbito esternal e morte. Na necropsia de um dos animais, foram observados sangue escuro (cor de chocolate) e de difícil coagulação, músculos esqueléticos e cardíaco intensamente vermelho-cereja, compartimentos gástricos distendidos por grande quantidade de gases e pulmões, rins, fígado e encéfalo amarronzados. Além disso, o cadáver exalava odor nitroso. O teste de difenilamina e a dosagem de nitrato na forragem (Pennisetum purpureum, "capim-elefante", cultivar Napier) oferecida aos animais revelaram concentração elevada de nitrato na planta, com diagnóstico de intoxicação por nitrato/nitrito. Os principais fatores que levaram à intoxicação foram atribuídos à adubação excessiva do capim com esterco bovino; à ocorrência de um período de estiagem seguido por um período chuvoso; à falta de adaptação dos animais à alimentação rica em nitrato; e à dieta composta, quase exclusivamente, por capim-elefante. Este trabalho é o primeiro relato de intoxicação espontânea por nitrato/nitrito em bovinos no sudeste do Brasil.
