Repeated handling, restraint, or chronic crowding impair the hypothalamic-pituitary-adrenocortical response to acute restraint stress

• Autorzy: Gadek-Michalska A. , Bugajski J.
• Języki publikacji: EN

Abstrakty

EN

The purpose of the present study was to assess whether, and to what extent prior handling, restraint or social crowding stress during 3-10 days affects the hypothalamic-pituitary-adrenocortical (HPA) response to an acute short-lasting restraint stress. Also the effect of a feedback inhibitory mechanism of corticosterone in the impairment of HPA axis by these stressors was investigated. Male Wistar rats were pretreated with handling 1 min/day for 3-10 days, restraint 2 times daily for 3-7 days and crowding stress for 7 days before exposure to acute restraint stress in metal tubes for 10 min. Some group of rats received exogenous s.c. corticosterone either once 25mg/kg or 2 times daily 10 mg/kg for 3-10 days before restraint stress. After the last restraint the rats were decapitated and their trunk blood was collected for the measurement of plasma ACTH and serum corticosterone levels. Handling for 3-7 days, restraint for 3-7 days, and crowding for 7 days and a single pretreatment with corticosterone - all significantly and to a similar extent inhibited the restraint stress-induced increase in ACTH and corticosterone secretion. Chronic pretreatment with corticosterone blunted the restraint stress-induced increase in HPA axis activity. These results indicate that repeated short-lasting stress induced by handling, restraint, or crowding potently attenuates the acute restraint stress-induced stimulatory action of the HPA axis. They also indicate adaptive action of moderate stress on the HPA axis response to acute stress. The results also suggest that a short-lasting hypersecretion of corticosterone during psychological stress may induce a prolonged feedback inhibition of the HPA axis activity. The attenuation of HPA axis response by prior handling has also obvious methodological implications.

Słowa kluczowe

EN

corticosterone secretion; corticosterone feedback inhibition; hypothalamic-pituitary-adrenocortical response; crowding stress; stress; handling; restraint

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2003
• Tom: 54
• Numer: 3
• Opis fizyczny: p.449-459,fig.,ref.

Twórcy

autor

Gadek-Michalska A.

• Polish Academy of Sciences, 12 Smetna Street, 31-343 Krakow, Poland

autor

Bugajski J.