Demonstration of 16-unsaturated C-19 steroids ('boar pheromones') in tissues of the male camel (Camelus dromedarius)

Investigations into the role of pheromones in reproductive behaviour have b een mainly limited to the boar, with 16-unsaturated C-19 steroids playing a major role. Similarities in the mating behaviour of the camel and pig sugg est that pheromones may also be important in the camel. The aim of this stu dy was to determine the concentrations of 16-unsaturated steroids in camel testes and other tissues. Samples of testicular tissue were obtained by cas tration from six male camels (9-15 years) and 16-unsaturated steroid conten t was measured by gas-liquid chromatography (GLC). In addition, samples of the glandula occipitalis ('poll gland'), g, parotis, g, submandibularis and the palatal flap ('dulaa') were obtained fi om a 10-year-old camel and als o analysed for steroid content. Results were confirmed by GC-MS (gas-chroma tography-mass spectrometry) in selected testicular samples. 5 alpha-androst -16-en-3-one could be detected in all testicular specimen (range 0.05-1.28 mu g/g tissue) as well as in all the other tissues analysed, with highest c oncentrations in the glandula occipitalis. 5 alpha-androst-16-en-3 beta-ol was present in most tissues, whereas 5 alpha-androst-16-en-3 alpha-ol was d etectable at 0.75 mu g/g only in one testes which also had the highest leve l of 5 alpha-androst-16-en-3-one. The similarities of these findings to the porcine species suggest a role of 16-unsaturated steroids as pheromones in the camel. Further experimental evidence however, is required to confirm t hese findings.