Effect of adrenalectomy and dexamethasone treatment on prolactin secretion of lactating rats

• Published in: Brain research bulletin 2001-12, Vol.56 (6), p.589-592
• Main Authors: Horváth, Katalin M, Bánky, Zsuzsanna, Tóth, Béla E, Halász, Béla, Nagy, György M
• Format: Article
• Language: English
• Subjects: Adrenalectomy; Adrenalectomy - adverse effects; Animals; Biological and medical sciences; Corticosteroids; Dexamethasone - pharmacology; Domperidone - pharmacology; Dopamine; Dopamine - metabolism; Dopamine Antagonists - pharmacology; Female; Formaldehyde - pharmacology; Fundamental and applied biological sciences. Psychology; Glucocorticoids - pharmacology; Hormone metabolism and regulation; Hypothalamo-Hypophyseal System - drug effects; Hypothalamo-Hypophyseal System - metabolism; Lactation; Lactation - drug effects; Lactation - physiology; Pain Measurement; Pituitary-Adrenal System - drug effects; Pituitary-Adrenal System - metabolism; Pregnancy. Parturition. Lactation; Prolactin; Prolactin - blood; Prolactin - metabolism; Rats; Rats, Sprague-Dawley; Receptors, Dopamine - drug effects; Receptors, Dopamine - metabolism; Stress; Stress, Physiological - metabolism; Stress, Physiological - physiopathology; Vertebrates: reproduction
• ISSN: 0361-9230; 1873-2747
• DOI: 10.1016/S0361-9230(01)00731-6

The contribution of corticosteroids to the control of prolactin secretion in lactating rats was investigated. The prolactin response to domperidone (20 μg/kg b.w., i.v.), a dopamine receptor antagonist and to domperidone plus formalin stress was tested in adrenalectomized and/or dexamethasone-treated continuously nursing rats. Animals were adrenalectomized on the 3rd day of lactation and tested on the 7th day of lactation. Dexamethasone was injected s.c. 24 h before testing (400 μg/kg b.w.) and on the day of testing (200 μg/kg b.w.). Domperidone caused a significant rise in plasma prolactin levels. The prolactin response to domperidone was twice as high in solely adrenalectomized dams and in solely dexamethasone-treated rats compared to controls. In adrenalectomized animals treated with dexamethasone, the prolactin response to domperidone was like in controls. Formalin injection to either adrenalectomized plus domperidone-treated animals or to animals injected with dexamethasone plus domperidone, resulted in a statistically significant depletion of plasma prolactin. In controls and in adrenalectomized animals receiving dexamethasone and domperidone, the prolactin response to formalin was very similar, i.e., plasma prolactin levels did not change after the administration of formalin. The present findings suggest that in lactating rats, corticosteroids are involved in the prolactin response to domperidone and to formalin stress.