Impaired protamination and sperm DNA damage in a Nellore bull with high percentages of morphological sperm defects in comparison to normospermic bulls

The routine semen evaluation assessing sperm concentration, motility and morphology, does not identify subtle defects in sperm chromatin architecture. Bulls appear to have stable chromatin, with low levels of DNA fragmentation. However, the nature of fragmentation and its impact on fertility remain unclear and there are no detailed reports characterizing the DNA organization and damage in this species. The intensive genetic selection, the use of artificial insemination and in vitro embryo production associated to the cryopreservation process can contribute to the chromatin damage and highlights the importance of sperm DNA integrity for the success of these technologies. Frozen-thawed semen samples from three ejaculates from a Nellore bull showed high levels of morphological sperm abnormalities (55.8±5.1%), and were selected for complementary tests. Damage of acrosomal (76.9±8.9%) and plasma membranes (75.7±9.3%) as well as sperm DNA strand breaks (13.8±9.5%) and protamination deficiency (3.7±0.6%) were significantly higher compared to the values measured in the semen of five Nellore bulls with normospermia (24.3±3.3%; 24.5±6.1%; 0.6±0.5%; 0.4±0.6% for acrosome, plasma membrane, DNA breaks and protamine deficiency, respectively) (P<0.05). Motility and percentage of spermatozoa with low mitochondrial potential showed no differences between groups. This study shows how routine semen analyses (in this case morphology) may point to the length and complexity of sperm cell damage emphasizing the importance of sperm function testing.

Inappropriate management conditions, especially for the regressed class, are related to sperm quality in Prochilodus lineatus

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

Sperm production of Steidachneridion parahybae (Steindachner 1877) and the effect of hormonal induction throughout one reproductive cycle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Absence of effects on the rat sperm quality after subacute exposure to low doses of fungicide prochloraz

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphometric evaluation of the rat testis, epididymis and vas deferens following chemical sympathectomy with guanethidine

Selective chemical sympathectomy of the internal sex organs of adult male rats was undertaken by long term administration of low doses of guanethidine. The spermatogenic activity of the testis was unaffected by treatment. Examination of the vas deferens using morphometric methods revealed a marked increase in luminal area in contrast to a decrease in muscle layer area and in epithelial height. This is morphological evidence of sperm accumulation caused by a disorder in ductal contractile activity. No structural changes were observed in the epididymis. However, the concentration of spermatozoa in the sperm suspension stored in the cauda epididymidis was significantly increased in denervated rats. This result is discussed in terms of a sympathetic control of resorption mechanisms in the epididymis.

Bupropion treatment increases epididymal contractility and impairs sperm quality with no effects on the epididymal sperm transit time of male rats

Bupropion is a dopamine (DA) and norepinephrine (NE) reuptake inhibitor used as smoking cessation and antidepressant drug with a lower incidence of male sexual dysfunction. We showed previously that sibutramine, a norepinephrine/serotonine reuptake inhibitor, reduced male rat fertility. As there are no studies evaluating the impact of bupropion treatment on spermatic parameters and male fertility, we evaluated the effects of bupropion treatment (15 and 30 mg kg(-1), 30 days) on sexual behavior, spermatic parameters and fertility of male Wistar rats and on the epididymal duct in vitro contractility. Bupropion 15 mg kg(-1) increased the serum luteinizing hormone level and the epididymal duct contractility, but the sperm quality was not affected. At 30 mg kg(-1) bupropion impaired sperm quality increasing the incidence of non-progressive sperm. The male sexual behavior and fertility were not modified at both bupropion doses. These results, in rats, suggest the importance of studies evaluating the effects of bupropion on the human male sperm quality.

Lack of reproductive toxicity in adult male rats exposed to interferon-alpha

Interferon-alpha (IFN- α ), a type I IFN, is a protein with antiviral, antiproliferative, and immunoregulatory activities, widely used in the treatment of several types of cancers as well as hepatitis B and C. Decrease of libido and erectile dysfunction are commonly reported by male patients during treatment of chronic hepatitis C with IFN- α . However, IFN therapy-associated underlying factors attributed to sexual dysfunction are still not well defined. Currently, there are few studies investigating the effects of IFN on male reproductive system functions. Given that, the aim of the present investigation was to examine effects of subchronic exposure to IFN- α (5 × 10(4) U/kg and 10 × 10(4) U/kg, 30 d) on serum hormones, sperm parameters, fertility, and testicular and epididymal hystopathology and morphometry in adult male Wistar rats. None of the evaluated parameters was markedly altered by IFN- α . Thus, our results suggest that exposure to IFN- α , in this experimental design, did not adversely affect sperm quality and fertile capacity of male rats.

Experimental glaucoma model (ischemia and reperfusion): histology, morphometry, protein and gene espression of apoptosis pathway

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

Influence of sperm motility factors on spermatozoa obtained from diffent epididymal segments

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

Comparison of apoptotic cells between cryopreserved ejaculated sperm and epididymal sperm in stallions

The development of a reliable technique to freeze epididymal semen would provide a unique opportunity to preserve valuable genetic material from unexpectedly lost stallions. The aim of this study was to compare the apoptotic indices of sperm obtained from ejaculate, sperm recently recovered from the epididymides (EP), and sperm recovered from epididymides stored at 5 C for 24 hours (EP-stored). For the first category, two ejaculates from seven stallions were collected and then submitted to cryopreservation using an egg yolk-based extender. One week after the last semen collection, the stallions were submitted to bilateral orchiectomy, and sperm from one of the cauda epididymis was harvested immediately after castration (EP). The remaining testicle was stored in a passive refrigeration container at 5 C for 24 hours before the cauda epididymal sperm was harvested (EP-stored). Sperm harvesting from the epididymis for EP and EP-stored was performed by retrograde flushing of the caudal portion of the epididymis using a skim milk-based extender. The recovered sperm was then cryopreserved using the egg yolk-based extender. Sperm motility parameters were studied by computerassisted semen analysis, and apoptosis was estimated by measuring caspase activity and membrane phospholipid translocation using epifluorescence microscopy. The samples were evaluated immediately (0 hour) and 8 hours after thawing. At 0 hour, no differences in sperm parameters were observed among the groups, but after 8 hours, significant statistical differences were observed in sperm motility parameters and plasma membrane integrity among the treatment groups. In addition, viable cells with no apoptotic signs were more prevalent in EP and EP-stored, suggesting that epididymal sperm is less sensitive to the cold shock caused by sperm cryopreservation.

Protein content of equine seminal plasma and sperm plasma membrane in subfertile stallions

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

A microestrutura e o desenvolvimento dos órgãos genitais masculinos de preás (Galea spixii) criados em cativeiro

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