RESUMO
Although stem cell therapy is a promising alternative for treatment of degenerative diseases, there are just few reports on the use of stem cells therapy in horse's reproductive system. This study aims to evaluate the effect of intratesticular injection of bone marrow mesenchymal stromal/stem cells (MSCs) in healthy stallions, and its outcome on seminal parameters and fertility. In Experiment 1, 24 stallions were divided into treatment group (TG) and control group (CG). In the TG, an intratesticular application of MSC was performed, and in the CG, only PBS was used. Measurements of testicular volume, surface temperature and Doppler ultrasonography were performed 24 and 48 hr after treatments. Fifteen days after application, the testicles were removed and submitted to histological analysis. In Experiment 2, 3 fertile stallions received similarly treatment with MSCs. Physical examination and sperm analysis were performed weekly during 60 days after treatment, and at the end, semen from one of them was used for artificial inseminations of 6 healthy mares. In Experiment 1, clinical examinations showed no signals of acute inflammation on both groups according to the analysed variables (p > .05). Also, no signal of chronic inflammation was observed on histological evaluation. In Experiment 2, stallions presented no physical alterations or changes in sperm parameters, and a satisfactory fertility rate (83%; 5/6) was observed after AI. The results support the hypothesis that intratesticular application of bone marrow MSCs is a safe procedure, and this could be a promising alternative to treat testicular degenerative conditions.
Assuntos
Transplante de Células-Tronco Mesenquimais/veterinária , Células-Tronco Mesenquimais , Testículo , Tolerância ao Transplante , Animais , Feminino , Fertilidade , Cavalos , Inseminação Artificial/veterinária , Masculino , Análise do Sêmen , Testículo/anatomia & histologia , Testículo/fisiologia , Transplante Homólogo/veterináriaRESUMO
Studies involving different methods and techniques of cryopreservation and its interactions with the conception rates in artificial insemination (AI) programs are reported in the literature. This study evaluated the sperm kinetics, plasma membrane integrity, and fertility rates of mares inseminated with cryopreserved stallion semen subjected to different freezing methods. For this, four ejaculates from five stallions were collected and frozen in conventional (Styrofoam box) or automated system in Mini-Digitcool ZH 400. Seminal samples were evaluated after thawing for sperm motion parameters by CASA and plasma membrane integrity by epifluorescence microscopy. For the fertility trial, a cross-over model was performed using 100 cycles of 50 mares, which were inseminated by one the two freezing methods. No differences were observed for sperm motion parameters and plasma membrane integrity between groups (P > .05). The pregnancy rate using the conventional method was 56% (28/50) and did not differ (P = .5406) from the pregnancy rate (64%, 32/50) obtained using the automatized method. The use of semen from fertile stallions may not illustrate small differences in the two freezing methods evaluated. Conventional and automated freezing systems did not differ in the quality and viability of fertile stallion semen and conception rates, indicating that the two methodologies can be safely used in AI programs.
Assuntos
Preservação do Sêmen/veterinária , Animais , Criopreservação/veterinária , Feminino , Fertilidade , Congelamento , Cavalos , Masculino , Gravidez , EspermatozoidesRESUMO
The aim of this study was to evaluate the impact of successive bovine testicular punctures using different needle sizes. Fifteen bulls were submitted to testicular needle aspiration (TNA) in the left and right testis using 18-gauge (40×12mm) or 22-gauge (25×7mm) needles, respectively, once every 30 days. Animals were randomly divided into three groups, which were submitted to bilateral orchiectomy two days after the last puncture. Group 1 (G1): only one puncture (n=5); Group 2 (G2): three consecutive punctures in a period of three months (n=5); Group 3 (G3): six consecutive punctures in a period of 6 months (n=5). Fragments from the medial portion of the testicular parenchyma were excised and fixed in Bouin's fluid for histological analysis. No differences were observed in the percentage of seminiferous tubules degeneration between G1, G2 and G3 (P>0.05). Higher amounts of erythrocyte were found in G1 and G2 groups compared to G3, in the intra- and intertubular tissue (P<0.05). There was no interaction between the needle gauge and the occurrence of testicular damage in animals submitted to one (G1) or three (G2) punctures. However, a higher percentage of tubular degeneration was associated to 18-gauge compared to 22-gauge fine needles in G3. In conclusion, multiple testicular needle aspiration can be safely conducted using fine needles. Large needles are recommended only for a single TNA, since multiple punctures may result in increased tubular degeneration and compromise testicular architecture and functionality.
RESUMO
Fertility rates of donkey semen in jennies are lower compared to mares. The aims of this study were to evaluate different sperm cryopreservation methods and insemination strategies to improve the fertility of donkey semen in jennies. Three experiments were performed: (1) the comparison of two freezing methods of donkey semen (conventional method and automated method); (2) the determination of a suitable insemination dose of fresh donkey semen for jennies and mares; and (3) the influence of the semen deposition site on fertility of jennies inseminated with frozen donkey semen. For experiment 1, no differences were observed in total motility, angular velocity, curvilinear velocity, straight-line velocity, and plasma membrane integrity between samples frozen with the conventional (Styrofoam box) and the automated method (TK 4000C). However, the automated method provided higher values of progressive motility and rapid cells in frozen-thawed samples in comparison with the conventional method (P < 0.05). For experiment 2, mares were bred using 500 × 10(6) fresh sperm (M); and jennies using 1 × 10(9) (J1) or 500 × 10(6) fresh sperm (J5). Pregnancy rates in M, J1, and J5 were 93% (14/15), 73% (11/15), and 40% (6/15), respectively. When using different insemination doses, 500 × 10(6) or 1 × 10(9) sperm, no significant difference was observed in pregnancy rates of mares (M, 14/15) and jennies (J1, 11/15). Furthermore, there was no significant difference between the two insemination doses in jennies. However, with an insemination dose of 500 × 10(6) fresh sperm, the pregnancy rates were significantly higher in mares (M, 14/15) than in jennies (J5, 6/15; P < 0.05). For experiment 3, the inseminations were carried out in the uterine body (UB) or in the uterine horn of jennies with frozen-thawed donkey semen. No pregnancies were achieved with inseminations performed in the UB (0/12). The pregnancy rate for uterine horn group was 28.26% (13/46) and thus significantly higher than the UB group (0%; 0/12; P < 0.05). In conclusion, the automated method showed higher values on progressive motility and rapid cells parameters compared to the conventional method and can be used as an alternative for freezing donkey semen. The increase in the number of sperm cells per insemination dose using fresh donkey semen improved the fertility rates in jennies. The deep horn inseminations using frozen-thawed donkey semen increased the pregnancy rate in jennies, and the multiple inseminations may be an option to improve the fertility rates of donkey semen in jennies.