Abstract
The adrenals play a key-role in the hormonal stress reactions and non-invasive methods are favoured for evaluating their activity, as blood sampling may cause an increase in these hormones. Above all, faeces offer the advantage that they can be collected easily and feedback free. Measurement of faecal glucocorticoid metabolites is used in an increasing number of species. However, literature concerning the excretion of catecholamines (CA) via the faeces is not available. The aim of this study was to gain basic information about the excretion of CA in sheep and swine. In addition the main faecal metabolites were characterised. This should clarify, whether or not methods for the determination of some of the relevant faecal metabolites can be developed to allow a non-invasive evaluation of sympathoadrenal activity during disturbances. Therefore, the percentage and the time course of the excreted radioactivity in urine and faeces were determined after intravenous injection of H-3-adrenaline (H-3-A) and H-3-noradrenaline (H-3-NA; 3.7 MBq each) in 4 sheep (2 of each sex; a total of 8 administrations) and 2 sows. Urinary and faecal samples were collected and radioactivity was measured by liquid scintillation counting. Administered CA were excreted mainly in the urine (>96 %). The highest radioactivity in the urine (per litre) of all animals was observed in one of the first 2 samples following injection, whereas in faeces it was measured with a delay of about 12 h in sheep and 48 h in sows. Thereafter, the radioactivity declined slowly and reached background levels within 4 weeks. In the faeces mainly metabolites of CA were present. However, due to the low amounts of faecal metabolites of the injected CA a quantitative measurement in sheep and sows seems to be not possible.