Behaviour of golden hamsters (Mesocricetus auratus) - Vetsuisse ...

DiscussionVarious concentrations of cortisol in golden hamsters under different (stress)situations have been published (App. VI). Possible causes of the differences in thehormonal reaction to stress have been directly investigated, namely age, differentstressors ((Wommack and Delville, 2003; Taravosh-Lahn and Delville, 2004),duration (Ottenweller et al. 1985), time of day (Albers et al. 1985), and experience(Weinberg and Wong, 1986). Different methods could explain the discrepant values.However, it is not clear why the studies of Wommack and Delville (2003) andTaravosh-Lahn and Delville (2004) obtained such different values under the samestress with the same hormonal analyses. Unknown influences varying with time mightbe very important and the factor age might be confounded with the factor time.Different aged individuals should be tested and their blood taken at the same time toattribute effects clearly to the age. Our cortisol concentrations in males could indicatethat they were acutely stressed at the time of blood sampling. This is supported bythe result that corticosterone, cortisol, cortisol/corticosterone ratio and ACTH mainlydepended on how much time was spent from first disturbance of the hamsters untilblood samples could be taken after euthanasia. It shows the sensitivity of thepituitary-adrenal axis (PAA). Cortisol was already elevated after three minutes of theinjection of ACTH. In some cases blood samples probably where taken at a pointwhen hormone levels had already begun to increase. On average, blood samples inmales were taken about 4 minutes after the first disturbance. Since the duration ofcatching the hamsters depended on the treatments (bedding depth or cage size) wecannot draw any conclusions concerning the state of stress in the hamsters inrelation to their treatments. The decrease of ACTH with time can be explained by the45