Control Methods and Evaluation of Bacterial Growth on Fresh and Cooled Stallion Semen

The penis and prepuce of the stallion have a high bacterial load on its surface, forming a natural microbial flora that contaminates the semen during ejaculation. Bacterial growth in semen may cause a decline on sperm quality, viability, and fertility and predisposes the occurrence of endometritis in inseminated mares. Thus, the aim of this study was to evaluate the effect of penile wash before semen collection, the addition of different commercial skim milk-based extenders containing antibiotics (BotuSemen and INRA96), and the removal of seminal plasma by filtration on the quality, viability, and bacterial proliferation on fresh and cooled stallion semen. Animals that were never submitted to penile wash before semen collection tended to have lower bacterial contamination in the ejaculate. Semen samples extended in BotuSemen showed superiority in total motility, progressive motility, average path velocity, and rapid sperm and lower bacterial contamination in relation to semen samples extended in INRA96 after 24 hours of cooling. No difference was found in these parameters between the storage temperatures (5 degrees C and 15 degrees C). Furthermore, the removal of seminal plasma by filtration reduced the bacterial load in semen after cooling. In conclusion, the penile wash before semen collection tended to reduce the bacterial growth in fresh semen. The use of a semen extender with appropriate antibiotics and removal of seminal plasma by filtration were effective in reducing the bacterial contamination and preserved the quality of cooled stallion semen. (C) 2015 Elsevier Inc. All rights reserved.

Amplification of neuromuscular transmission by methylprednisolone involves activation of presynaptic facilitatory adenosine A(2A) receptors and redistribution of synaptic vesicles

The mechanisms underlying improvement of neuromuscular transmission deficits by glucocorticoids are still a matter of debate despite these compounds have been used for decades in the treatment of autoimmune myasthenic syndromes. Besides their immunosuppressive action, corticosteroids may directly facilitate transmitter release during high-frequency motor nerve activity. This effect coincides with the predominant adenosine A(2A) receptor tonus, which coordinates the interplay with other receptors (e.g. muscarinic) on motor nerve endings to sustain acetylcholine (ACh) release that is required to overcome tetanic neuromuscular depression in myasthenics. Using myographic recordings, measurements of evoked [H-3]ACh release and real-time video microscopy with the FM4-64 fluorescent dye, results show that tonic activation of facilitatory A(2A) receptors by endogenous adenosine accumulated during 50 Hz bursts delivered to the rat phrenic nerve is essential for methylprednisolone (03 mM)-induced transmitter release facilitation, because its effect was prevented by the A(2A) receptor antagonist, ZM 241385 (10 nM). Concurrent activation of the positive feedback loop operated by pirenzepine-sensitive muscarinic M-1 autoreceptors may also play a role, whereas the corticosteroid action is restrained by the activation of co-expressed inhibitory M-2 and Al receptors blocked by methoctramine (0.1 mu M) and DPCPX (2.5 nM), respectively. Inhibition of FM4-64 loading (endocytosis) by methylprednisolone following a brief tetanic stimulus (50 Hz for 5 s) suggests that it may negatively modulate synaptic vesicle turnover, thus increasing the release probability of newly recycled vesicles. Interestingly, bulk endocytosis was rehabilitated when methylprednisolone was co-applied with ZM241385. Data suggest that amplification of neuromuscular transmission by methylprednisolone may involve activation of presynaptic facilitatory adenosine A(2A) receptors by endogenous adenosine leading to synaptic vesicle redistribution. (C) 2014 Elsevier Ltd. All rights reserved.

Spermatic and testicular damages in rats exposed to ethanol: Influence of lipid peroxidation but not testosterone

Chronic consumption of ethanol causes morphological and physiological changes in the reproductive system of mammals. Vitamin C has an antioxidant role in organisms by neutralizing the ROS (reactive oxygen species) produced by oxidizing agents and this vitamin has an important function in the male reproductive system. The aim of this study was to evaluate whether vitamin C could prevent or attenuate the alterations in the male reproductive system caused by ethanol consumption. To test this hypothesis, male rats were divided into three experimental groups and treated by gavage for 63 days. The ethanol (E) and ethanol +vitamin C (EC) groups received 2 g/kg of ethanol (25% v/v) daily. In addition to ethanol, the EC group received vitamin C at a dose of 100 mg/day, diluted in water. The control group (C) received only the vehicle. On the 64th experimental day, the animals were anesthetized and euthanized, and blood was collected for plasmatic hormonal analysis. The testis, epididymis, vas deferens, and seminal vesicles were removed and weighed. Sperm from the vas deferens was submitted to morphological and motility analysis. The testis and epididymis were used for oxidative stress and histopathological analysis, sperm count, morphometric analysis of the testis, and stereological analysis of the epididymis. The results showed that vitamin C has a protective effect in the testes of adult male rats, entirely normalizing the parameters of sperm count, spermatogenesis kinetics, lipid peroxidation levels, and sperm motility, as well as partially normalizing the histopathological damage in the testis, epididymis, and sperm morphology. Thus, we concluded that lipid peroxidation is a major mechanism by which ethanol affects the testes and sperm, whereas no plasmatic testosterone alterations were found.

Tests of fed and unfed Amblyomma cajennense ticks (Acari: Ixodidae): first morphological data

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

Comparative analysis of the male reproductive accessory glands of bat species from the five brazilian subfamilies of the family phyllostomidae (Chiroptera)

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

Induced reproduction and early development histology of Oscar Astronotus ocellatus (Agassiz, 1831)

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

Spermatozoon ultrastructure and semen parameters of Brycon vermelha (Characiformes, Characidae)

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)

Some effects of cimetidine on the reproductive organs of rats

1. The development of genital organs of rats chronically treated with cimetidine showed that the drug may present anti-androgenic activity. 2. This treatment did not alter the sensitivity of vas deferens to noradrenaline, but increased their sensitivity to BaCl2. 3. In the male reproductive system, cimetidine must have peripheral actions apart from the central ones observed after chronic treatment.