The Journal of Reproduction and Development Supplement

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The present study was planned to study the effects of different concentrations of catalase enzyme (CE; 0, 250, 500 and 1000 IU/ml) addition to the extended cooled dromedary camel semen (DCS) with Tris-yolk-fructose (TYF) extender on semen quality and enzymatic activities, during storage at 5?C for up to 5 days. Conception rates of she-camel artificially inseminated with whole fresh or extended cooled camel semen without or with 500 IU/ml CE, were also estimated. The results showed that supplementation of CE at 250 or 500 IU/ml to the extended cooled DCS increased significantly the percentage of sperm motility and decreased significantly the percentage of dead spermatozoa, sperm abnormalities and acrosomal damage. Also, supplementation of CE at 250 or 500 IU/ml decreased significantly the amounts of aspartate-aminotransferase (AST), alanine-aminotransferase (ALT) and alkaline phosphatase (ALP) enzymes released into the extracellular medium during storage at 5?C. The highest value of the percentage of sperm motility was recorded with the extended cooled DCS supplemented with CE at 500 IU/ml and the lowest value was recorded with CE at 1000 IU/ml. While, the lowest value of the percentage of dead spermatozoa, sperm abnormalities, acrosomal damage of spermatozoa were recorded with the extended cooled DCS supplemented with 500 IU/ml and the highest value were recorded with CE at 1000 IU/ml. The advancement of storage time at 5?C decreased significantly the percentages of sperm motility and increased significantly the percentages of dead spermatozoa, sperm abnormalities, acrosomal damage of spermatozoa and the amounts of AST, ALT and ALP enzymes released into the extracellular medium.

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Due to the high risks of extinction and increasing concerns about decreasing in genetic diversity of ex situ population, a great effort has been devoted to the establishment of a self-sustaining population of Asian elephants in Thailand. Male subfertility attributed from poor motility and immotile of spermatozoa was found in high proportion of overall ejaculates obtained from a manual collection technique. The searching of motility stimulation for elephant sperm may be improving a quality of the preserved semen. The objective of this study was to investigate the effects of pentoxifyllines (PTX) on stimulating motility in elephant semen with low-motile sperm. Eleven ejaculates were collected from 8 elephant bulls by manual stimulation and were separated into two groups: poor- and low-motile sperm groups. PTX was added to the semen samples at a final concentration of 0.5, 1.0 and 2.0 mg/ml. Samples without PTX were use as control. Semen analysis was performed at 15 and 30 min after incubation at 37 C using computer-assisted semen analysis. PTX did not significantly improve percentage of total and progressive motility, and characteristics of sperm motion in both groups. However, in a low-motile sperm group, PTX treatment could maintain the percentages of total and progressive motility, path velocity (VAP) and progressive velocity (VSL) on the higher level than a control group. The present study indicates that supplementation with PTX has a tendency for partially maintaining rather than increasing sperm motility and sperm motions in Asian elephant semen with low-motile sperm.

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Metastin neurons are located in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) with their fibers found in the median eminence (ME) and medial preoptic area. The present study aims to determine the neuronal projection of the two metastin neuronal populations in female rats in order to provide the morphological basis for the action site to stimulate GnRH release. Female rats were injected i.v. with FluoroGold (FG), a retrograde tracer and the others were stereotaxically injected with FG into the ARC. Colchicine was then injected into the lateral cerebroventricle. Some animals were ovariectomized and the others were primed with high dose of estrogen to enhance metastin immunoractivities in the ARC and AVPV, respectively. Coronal sections of the brain were made on a cryostat and dualstained with anti-FG and -metastin. Dual fluorescent immunohistochemistry revealed that 75% of metastin-immunopositive neurons in the ARC, but 5% of AVPV metastin-immunopositive neurons showed FG-immunoreactivities in animal with i.v. FG injection. This indicates that most metastin neurons projecting to the ARC-ME region originate in the ARC. Approximately 50% of metastin neurons in the AVPV had FG-immunoreactivities in animals with ARC FG injection, indicating that half of AVPV metastin neurons project to the ARC-ME region. Taken together, AVPV metastin neurons might have their neuronal terminals projecting to the ARC. In addition, most of the ARC metastin neurons might be neuroendocrine neurons projecting to the ME. In conclusion, both AVPV and ARC metastin neurons may control GnRH release at their terminals in the ARC-ME region.

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Hatano high (HAA)- and low (LAA)-avoidance rats are two lines of Sprague-Dawley rats genetically selected on the basis of their active avoidance behavior in a shuttle-box. They also differ in several other behavioral responses, such as their locomotors activity in novel environments (open-field, circular corridor), with the HAA rats being more active than the LAA animals, as well as in endocrine reactivity, immune functions and stress response. We therefore set out to investigate the adrenal endocrinology of the HAA and LAA strains. It was found that the LAA rats had a significantly blunted ACTH response to restraint stress compared with HAA, but higher corticosterone and prolactin (PRL) response. This finding suggested that the HAA adrenal is less sensitive to ACTH than LAA. This was confirmed by investigating the corticosterone dose response to ACTH in adrenals from the two strains incubated in vitro. Several possible intra-adrenal regulators were investigated. The level of expression of steroidogenic acute regulatory (StAR) and long form of PRL receptors (PRLR-L) mRNA were higher in LAA rats as compared with HAA rats, but lower expression of melanocortin-2 receptors (MC2R) and CYP11A1 mRNA. These finding clearly demonstrate that the adrenals of the HAA strain have a diminished sensitivity to stimulation with ACTH, while the LAA have increased sensitivity. We purpose that PRL is responsible for increasing adrenocortical responses to ACTH stimulation in the LAA strain. The observed changes in adrenal sensitivity to ACTH suggest that this rat strain may have considerable implications for the animals' adaptive stress response.

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