Fertility of rat epididymal sperm after chemically and surgically induced sympathectomy

Guanethidine, a chemical that selectively blocks sympathetic noradrenergic neurons, was used to investigate the role of sympathetic innervation in the fertility of rat epididymal sperm, using both natural mating and in utero insemination protocols. This animal model correlates, at least in part, with spinal cord injury (SCI) in men. Adult male rats were treated daily by i.p. injections, for 21 or 42 days, with 0 or 6.25 mg/kg guanethidine. To compare the effects of guanethidine-induced sympathectomy with those following surgically induced sympathectomy, the inferior mesenteric ganglion and the proximal hypogastric nerves were removed in another group of rats. Both chemically and surgically induced sympathectomy increased the weight of the epididymis and seminal vesicles/coagulating glands as well as the number and the transit time of cauda epididymal sperm. Neither serum testosterone levels nor LH was affected by treatment with guanethidine. Using natural mating, no litters were produced by guanethidine-treated rats. Chemically denervated rats failed to produce copulatory plugs or ejaculate into the uterus. However, distal cauda epididymal sperm from chemically or surgically denervated rats displayed normal fertilization ability (80%) using in utero inseminations. In addition, the sperm of denervated rats did not show abnormal sperm chromatin structure using an assay that detects DNA damage. We conclude that sympathectomy delays the transit of sperm through the cauda epididymidis and produces ejaculatory dysfunction but does not compromise sperm quality in the distal cauda epididymidis. Moreover, these data provide compelling evidence that there is no association between the prolonged transit time of sperm within the epididymis, i.e., pre-ejaculatory sperm aging, and the fertility of those sperm, which has important implications for artificial insemination using sperm from men with SCI.

In utero protein restriction causes growth delay and alters sperm parameters in adult male rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of Sperm DNA Peroxidation in Fertile and Subfertile Dogs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Heparin and penicillamine-hypotaurine-epinephrine (PHE) solution during bovine in vitro fertilization procedures impair the quality of spermatozoa but improve normal oocyte fecundation and early embryonic development

The presence of heparin and a mixture of penicillamine, hypotaurine, and epinephrine (PHE) solution in the in vitro fertilization (IVF) media seem to be a prerequisite when bovine spermatozoa are capacitated in vitro, in order to stimulate sperm motility and acrosome reaction. The present study was designed to determine the effect of the addition of heparin and PHE during IVF on the quality and penetrability of spermatozoa into bovine oocytes and on subsequent embryo development. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes and mitochondrial function, was diminished (P < 0.05) in the presence of heparin and PHE. Oocyte penetration and normal pronuclear formation rates, as well as the percentage of zygotes presenting more than two pronuclei, was higher (P < 0.05) in the presence of heparin and PHE. No differences were observed in cleavage rates between treatment and control (P > 0.05). However, the developmental rate to the blastocyst stage was increased in the presence of heparin and PHE (P > 0.05). The quality of embryos that reached the blastocyst stage was evaluated by counting the inner cell mass (ICM) and trophectoderm (TE) cell numbers and total number of cells; the percentage of ICM and TE cells was unaffected (P > 0.05) in the presence of heparin and PHE (P < 0.05). In conclusion, this study demonstrated that while the supplementation of IVF media with heparin and PHE solution impairs spermatozoa quality, it plays an important role in sperm capacitation, improving pronuclear formation, and early embryonic development. © 2013 The Society for In Vitro Biology.

Investigação da toxicidade reprodutiva do fungicida Procloraz, com ênfase sobre aspectos morfofuncionais do epidídimo de ratos adultos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência dos danos oxidativos na qualidade espermática em bovinos de diferentes idades

Pós-graduação em Medicina Veterinária - FCAV

Viabilidade da dose fracionada de sêmen bovino criopreservado descongelada por diferentes métodos

Considerando a baixa concentração espermática necessária para promover a fecundação de oócitos na FIV, objetivou-se com este trabalho avaliar a qualidade da dose de sêmen bovino criopreservada após o seu fracionamento em duas partes visando um maior aproveitamento da mesma em programa de PIV. O experimento foi realizado utilizando 110 doses de sêmen congeladas em palhetas de 0,25 mL proveniente de 10 touros, que foram divididas em etapas: Uma dose representou o grupo controle, 5 foram destinadas para o grupo de descongelação direta (DD) e 5 para o grupo de descongelação indireta (DI). As doses foram fracionadas em duas partes, formando para cada grupo dois subgrupos, unidade da esfera (UE) e unidade do álcool polivinílico (UAP). O primeiro subgrupo teve análise imediata; e o segundo foi analisado após 24h de armazenamento em N₂. Os dados foram analisados por estatística descritiva, teste de Kruskal-Wallis e SNK (P < 0,05), apresentando motilidade e vigor: DI- imediata: 48,8% / 2,4; DI-24h: 54,2% / 2,5; DD-imediata: 67,8% / 3,0; DD-24h: 69,6% / 3,0; Controle: 70% / 3,0. Para lesão de acrossoma e integridade da membrana: DI- imediata: 24,3% / 40,5%; DI-24h: 36,2% / 44,3%; DD-imediata: 12,8% / 63,6%; DD-24h: 12,6% / 59,0%; controle: 11,9% / 57,5%. Média de concentração espermática: DI- imediata: 6,1×10⁶ DI-24h: 7,2×10⁶; DD- imediata: 8.2×10⁶; DD-24h: 7.8×10⁶ espermatozóide/fração de dose. Deste modo para o fracionamento da dose de sêmen bovino criopreservado o melhor método de descongelação foi o direto, uma vez que apresentou os melhores resultados em todos os parâmetros analisados.

Estudo genético quantitativo das características andrológicas de touros jovens da raça Nelore

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade espermática após seleção por centrifugação em Ovipure® ou gradiente de Percoll® do sêmen ovino criopreservado

Pós-graduação em Biotecnologia Animal - FMVZ

Isolate((R)) and Optiprep((R)) minigradients as alternatives for sperm selection in bovine in vitro embryo production

The objective of this study was to evaluate alternatives in small volumes to conventional gradient of Percoll((R)) on semen quality, in vitro embryo production, sex ratio and embryo survival after vitrification. Thawed semen was randomly allocated to one of four density gradient selection methods: (1) conventional Percoll((R)) (P), (2) MiniPercoll (MP), (3) MiniIsolate (MI), and (4) MiniOptiprep (MO). Sperm kinetics and quality were evaluated. Use of P, MP and MI gradients did not affect sperm motility (P > 0.05). However, there was a decrease in total and progressive sperm motility in MO (70.8 and 51.3% vs. 87.3 and 69.5% for P; 87.3 and 73% for MP; 92.3 and 78.8% for MI; P < 0.05). The MO had lower membrane integrity compared with P, MP and MI (39.7 vs. 70.5, 72.3, 63.8%, respectively, P < 0.05). The percentage of blastocysts produced was higher in MI than in MP and MO (21.1 vs. 16.1 and 16.9%, P < 0.05) and similar to P (18.4%; P > 0.05). Sex ratio and embryo survival after vitrification were similar among groups (P > 0.05). Semen selected by Isolate and Optiprep gradient, at the concentrations and small volumes used, demonstrated similar characteristics and in vitro embryo production to conventional Percoll((R)) gradient.

Improved sperm cryosurvival in diluents containing amides versus glycerol in the Przewalski's horse (Equus ferus przewalskii)

Two studies were conducted to understand sperm cryosensitivity in an endangered equid, the Przewalski's horse (Equus ferns przewalski), while testing the cryoprotectant ability of formamides. The first assessed the toxicity of permeating cryoprotectants (glycerol, methylformamide IMF] and dimethylformamide [DMF]) to Przewalski's horse spermatozoa during liquid storage at 4 C. The second examined the comparative influence of three diluents (with or without formamides) on cryosurvival of sperm from the Przewalski's versus domestic horse. When Przewalski's horse spermatozoa were incubated at 4 C in INRA 96 with differing concentrations of glycerol, MF or DMF or a combination of these amides, cells tolerated all but the highest concentration (10% v/v) of MF alone or in combination with DMF, both of which decreased (P < 0.05) motility traits. There was no effect of cryoprotectants on sperm acrosomal integrity. In the cryosurvival study, average sperm motility and proportion of cells with intact acrosomes in fresh ejaculates were similar (P> 0.05) between the Przewalski's (67%, 84%, respectively) and domestic (66%, 76%) horse donors. Sperm from both species were diluted in lactose-EDTA-glycerol (EQ), Botu-Crio (BOTU; a proprietary product containing glycerol and MF) or SM (INRA 96 plus 2% [v/v] egg yolk and 2.5% [v/v] MF and DMF) and then frozen over liquid nitrogen vapor. After thawing, the highest values recovered for total and progressive sperm motility, acrosomal integrity and mitochondria] membrane potential were 42.4%, 21.8%, 88.7% and 25.4 CN (CN = mean JC-1 fluorescence intensity/cell on a channel number scale), respectively, in the Przewalski's and 49.3%, 24.6%, 88.9% and 25.8 CN, respectively, in the domestic horse. Although sperm progressive motility and acrosome integrity did not differ (P> 0.05) among treatments across species, mitochondrial membrane potential was higher (P< 0.05) in both species using EQ compared to BOTU or SM media. Additionally, Przewalski's stallion sperm expressed higher (P < 0.05) post-thaw total motility in BOTU and SM compared to EQ whereas there were no differences among freezing diluents in the domestic horse. In summary, Przewalski's stallion sperm benefit from exposure to either MF or DMF as an alternative cryoprotectant to glycerol. Overt sperm quality appears similar between the Przewalski's and domestic horse, although the total motility of cells from the former appears more sensitive to certain freezing diluents. Nonetheless, post-thaw motility and acrosomal integrity values for Przewalski's horse spermatozoa mimic findings in the domestic horse in the presence of INRA 96 supplemented with 2% (v/v) egg yolk and a combined 2.5% concentration of MF and DMF. Published by Elsevier Inc.

Impact of adrenalectomy and dexamethasone treatment on testicular morphology and sperm parameters in rats: insights into the adrenal control of male reproduction

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Toxicologia reprodutiva de ratos adultos expostos ao 2,3,7,8-Tetraclorodibenzo-P-Dioxina (TCDD) in útero

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sperm characteristics of Steindachneridion parahybae (Steindachner, 1877) throughout 112h of storage at four temperatures

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Perfil lipídico da membrana plasmática e alterações morfofuncionais de esperamatozóides de garanhões resistentes e sensíveis à criopreservação

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)