Stimulation of kappa opiate receptors in intestinal wall affects stress- induced increase of plasma cortisol in dogs

Author(s): Alvinerie, M., Junien, J. L., Bueno, L.

Journal/Book: Brain Res. 1989; 502: 143-8.

Abstract: In dogs, an acoustic stress (A.S.) produced by hearing of intense music (less than or equal to 90 dB) through earpieces for 1 h induced a 520% maximal rise in plasma cortisol 15-30 min after the beginning of stress. Oral administration of the specific kappa agonists, U-50488 (0.1 mg/kg) and PD 117302 (0.05 mg/kg), 30 min before the A.S. session reduced significantly (P less than 0.01) by 71.2% and 80.9% the maximal increase of plasma cortisol but did not affect the increase observed after intracerebroventricular administration of ovineCRF (100 ng/kg). These effects which are not reproduced by intravenous administration of the drugs at similar doses, were blocked by previous treatment with MR 2266 (0.1 mg/kg) or local anesthesia and vagotomy, suggesting that kappa opioid agonists inhibit the stress-induced activation of the hypothalamo-pituitary-adrenocortical (HPA) system by acting selectively on specific receptors located in the wall of the proximal gut.

Keyword(s): Acoustic Stimulation. Administration, Oral. Animal. Corticotropin-Releasing Hormone/pharmacology. Dogs. Hydrocortisone/blood. Injections, Intraventricular. Intestines/drug effects/innervation. Male. Pyrroles/administration & dosage/pharmacology. Pyrrolidines/administration & dosage/pharmacology. Receptors, Opioid/physiology. Stress, Psychological/metabolism. Support, Non-U.S. Gov't. Thiophenes/administration & dosage/pharmacology

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