@article{vanderklok_penfold_siegal-willott_citino_2008, title={Idiopathic Infertility in Two Captive Male Gerenuk (Litocranius walleri walleri)}, DOI={10.1638/2007-0090.1}, abstractNote={Two adult male gerenuk (Litocranius walleri walleri) were confirmed infertile with distinctly varying clinical presentations. One animal had unilateral testicular degeneration/hypoplasia, and within 8 mo experienced atrophy/degeneration of the remaining testicle. The second animal had been previously treated with melengesterol acetate (MGA) milled in feed for 1 yr during puberty as part of an aggression-control study. The testes in this individual appeared normal both visually and on palpation; however, repeated semen collection consistently produced ejaculates containing high numbers of immotile spermatozoa, all of a single abnormal morphology: shortened tails, with normal total sperm counts for this species. Both gerenuk had cortisol concentrations within normal ranges for adult male gerenuk. Analysis of serum mineral concentration revealed zinc levels that would be considered low in domestic cattle. Testosterone levels were low for the animal discussed in case 1, but were within normal range for the animal in case 2 compared with other gerenuk. Investigations into endocrine causes, such as abnormal thyroid hormone concentrations and adrenal function, were unrewarding. Both animals discussed in this report are maternally related; therefore, a genetic cause of infertility cannot be ruled out. Further investigation into MGA, as well as the dietary zinc requirements for gerenuk, and resulting effects on spermatogenesis and testicular development are warranted.}, number={3}, journal={Journal of Zoo and Wildlife Medicine}, author={VanderKlok, Carin M. and Penfold, Linda M. and Siegal-Willott, Jessica and Citino, Scott B.}, year={2008}, month={Sep} }
 @article{moeser_klok_ryan_wooten_little_cook_blikslager_2007, title={Stress signaling pathways activated by weaning mediate intestinal dysfunction in the pig}, volume={292}, ISSN={0193-1857 1522-1547}, url={http://dx.doi.org/10.1152/ajpgi.00197.2006}, DOI={10.1152/ajpgi.00197.2006}, abstractNote={Weaning in the piglet is a stressful event associated with gastrointestinal disorders and increased disease susceptibility. Although stress is thought to play a role in postweaning intestinal disease, the mechanisms by which stress influences intestinal pathophysiology in the weaned pig are not understood. The objectives of these experiments were to investigate the impact of weaning on gastrointestinal health in the pig and to assess the role of stress signaling pathways in this response. Nineteen-day-old pigs were weaned, and mucosal barrier function and ion transport were assessed in jejunal and colonic tissues mounted on Ussing chambers. Weaning caused marked disturbances in intestinal barrier function, as demonstrated by significant (P < 0.01) reductions in transepithelial electrical resistance and increases in intestinal permeability to [3H]mannitol in both the jejunum and colon compared with intestinal tissues from age-matched, unweaned control pigs. Weaned intestinal tissues exhibited increased intestinal secretory activity, as demonstrated by elevated short-circuit current that was sensitive to treatment with tetrodotoxin and indomethacin, suggesting activation of enteric neural and prostaglandin synthesis pathways in weaned intestinal tissues. Western blot analyses of mucosal homogenates showed increased expression of corticotrophin-releasing factor (CRF) receptor 1 in the jejunum and colon of weaned intestinal tissues. Pretreatment of pigs with the CRF receptor antagonist alpha-helical CRF(9-41), which was injected intraperitoneally 30 min prior to weaning, abolished the stress-induced mucosal changes. Our results indicate that weaning stress induces mucosal dysfunction mediated by intestinal CRF receptors and activated by enteric nerves and prostanoid pathways.}, number={1}, journal={American Journal of Physiology-Gastrointestinal and Liver Physiology}, publisher={American Physiological Society}, author={Moeser, Adam J. and Klok, Carin Vander and Ryan, Kathleen A. and Wooten, Jenna G. and Little, Dianne and Cook, Vanessa L. and Blikslager, Anthony T.}, year={2007}, month={Jan}, pages={G173–G181} }