Hormonal responses to fighting in hamsters: separation of physical and psychological causes.
Male Syrian hamsters were paired and allowed to interact with a conspecific for 15 min a day for 4 days. On the fifth day, the animals were again paired, but they were kept physically separated by a mesh partition that allowed visual, olfactory, and auditory contact between the animals. Controls were placed with conspecifics on each of the 5 testing days, but the partition between them was never removed. Hamsters that were submissive on days 1-4 exhibited elevated plasma adrenocorticotropin-like immunoreactivity (ACTH-LI), beta-endorphin-like immunoreactivity (B-EP-LI), and cortisol on day 5 even though no fighting occurred on that day. Dominant hamsters did not differ from controls. These data support the hypothesis that there is an important psychological component to the pituitary-adrenocortical response in defeated hamsters.
Huhman
K L
KL
Department of Medical Neurosciences, Walter Reed Army Institute of Research, Washington, DC 20307-5100.
Moore
T O
TO
Mougey
E H
EH
Meyerhoff
J L
JL
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000374:Aggression / Q000502:physiology*; D000378:Agonistic Behavior / Q000502:physiology*; D000818:Animals; D001143:Arousal / Q000502:physiology*; D006224:Cricetinae; D004291:Dominance-Subordination; D006728:Hormones / Q000097:blood*; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008647:Mesocricetus; D010913:Pituitary-Adrenal System / Q000502:physiology*; D011333:Pro-Opiomelanocortin / Q000097:blood; D011388:Prolactin / Q000097:blood; D001615:beta-Endorphin / Q000097:blood
D006728:Hormones; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D006854:Hydrocortisone