Cortisol and Immune Measures in Boars Exposed to Three-day Administration of Exogenous Adrenocorticotropic Hormone

Abstract

The aim of the study was to evaluate the effect of adrenal stimulation by adrenocorticotropic hormone (ACTH) on blood cortisol concentration and on circulating total and differential leukocyte counts during and in the 16 days after ACTH administration. Swedish Landrace boars aged approximately 6-7 months were used. ACTH-treated animals (n = 7) were given ACTH intravenously at 10 microg/kg body mass for 3 days. A control group of animals (n = 7) received 1 ml of sterile 0.9% saline intramuscularly. ACTH induced a highly significant increase (p>0.0001) in serum cortisol in treated boars. On the day after the last ACTH dose, the cortisol concentration was significantly higher, but the level of significance was lower than during ACTH administration (p>0.05). During ACTH treatment, a significant increase was recorded in total leukocyte count and neutrophil percentage (p>0.05 to p>0.0001), along with the increase in blood cortisol concentration, whereas percentage lymphocyte count showed a significant decrease. Lymphopenia disappeared upon cessation of treatment, but neutropenia developed in the week after treatment. On all three days of ACTH challenge, the neutrophil-to-lymphocyte ratio was significantly increased. An increase in eosinophil percentage was recorded on treatment days 1 and 2, whereas ACTH treatment had no effect on basophil percentage. In conclusion, three-day administration of ACTH to young boars during restraint caused effects similar to acute stress situations, as suggested by disappearance of the effects on immune function after the last drug dosage.

Endocrine and immunological responses to adrenocorticotrophic hormone (ACTH) administration in juvenile harbor seals ( Phoca vitulina ) during winter and summer

“…The immunosuppressive effect of elevated GC concentrations associated with stressors has been well established in mammals (Keller et al, 1981;Deguchi and Akuzawa, 1998;Bilandzic et al, 2006). In addition to quantifying circulating white blood cell populations, we assessed the adaptive immune response through an in vitro PBMC proliferation assay.…”

Effect of ACTH Administration on Biochemical and Immune Measures in Boars

“…Regarding the hypothalamic–pituitary–adrenal axis, it is clear that glucocorticoid release is related to the intensity of stress when low to middle intensity stressors are studied, but not when a high intensity stress is induced (Hennessy and Levine, 1978; Amario et al., 1986). In pigs, the hypothalamic–pituitary–adrenal axis responds rapidly and sensitively to acute physical stress (Becker et al., 1985; Hicks et al., 1998) or ACTH challenge (Janssens et al., 1994; Haussmann et al., 2000; Mwanza et al., 2000; Bilandžić et al., 2005) by an increase in the blood cortisol concentration and returns to normal levels within 2 h. Also, cortisol response to ACTH in pigs was consistent during the experimental period, indicating that adrenocortical reactivity is an individual characteristic (Hennessy et al., 1988; von Borell and Ladewig, 1989; Janssens et al., 1994). In our previous study, the administration of ACTH induced a time‐dependent adrenocortical response and significant increase in serum cortisol concentration 90 min after injection on all 3 days of ACTH treatment in young boars (Bilandžić et al., 2005).…”

The use of leukocyte profiles to measure stress in vertebrates: a review for ecologists

“…Similar research has been conducted using adrenocorticotrophic hormone (ACTH), which stimulates release of glucocorticoids from the adrenal glands. Treatment with ACTH increases N : L ratio in boars (Bilandžič et al . 2006) and horses (Rossdale, Burguez & Cash 1982), probably via its effects on glucocorticoid secretion.…”