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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Morphine-Induced Changes in Opioid Sensitivity in Postpartum Females: A Unique Progesterone Response

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Sukikara, M. H. [1, 2] ; Cruz, A. M. [1] ; Felippe, E. C. G. [1] ; Anselmo-Franci, J. A. [3] ; Canteras, N. S. [4] ; de Oliveira, C. A. [5] ; Felicio, L. F. [1]
Total Authors: 7
[1] Univ Sao Paulo, Dept Patol, Fac Med Vet & Zootecnia, BR-05508900 Sao Paulo - Brazil
[2] Univ Cidade Sao Paulo, Lab Bases Neurais Comportamento, Sao Paulo - Brazil
[3] Univ Sao Paulo, Fac Odontol Ribeirao Preto, Dept Fisiol, BR-14049 Ribeirao Preto - Brazil
[4] Univ Sao Paulo, Dept Anat, Inst Ciencias Biomed, BR-05508900 Sao Paulo - Brazil
[5] Univ Sao Paulo, Dept Reprod Anim, Fac Med Vet & Zootecnia, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 5
Document type: Journal article
Source: Journal of Neuroendocrinology; v. 23, n. 11, SI, p. 1134-1138, NOV 2011.
Web of Science Citations: 5

Opioid peptides play an important role in maternal behaviour, as well as in physiological and pathological phenomena involving motivation. Daily 3.5 mg/kg doses of morphine from days 17-21 of pregnancy are able to change the expression of maternal behaviour patterns. However, the role of hormones on such opioid behavioural actions remains to be determined. The present study investigated the endocrine responses to this morphine treatment. Corticosterone, progesterone, oestradiol and prolactin serum concentrations were measured after each morphine injection. No significant differences were found in corticosterone, oestradiol or prolactin serum concentrations. The results suggest that the treatment was unable to promote different effects, other than those caused by saline injections. In morphine-treated animals, however, progesterone concentrations were consistently and significantly increased from days 18-20 of treatment. Thus, because this behavioural meaningful opioidergic stimulation during late pregnancy affects progesterone levels, the findings of the present study raise the hypothesis that this hormone may play a role in morphine-induced changes in opioid sensitivity during late pregnancy and early lactation. (AU)