Effect of opioids and opioid receptors antagonists on the anterior pituitary hormone secretions in man

The effects of morphine and nafloxone [Opioid receptor antagonist] on secretion of LH, FSH, GH and prolactin hormone were studied in twenty male subjects aged 35-45 years. The results revealed that morphine injection increased FSH, GH and prolactin hormone secretion without a significant effect on LH release, while naloxone injection increased LH and decreased prolactin hormone release without a significant change on FSH and GH release. These data show that both opioids and opioid receptors antagonists exert a rariety of effects on the anterior pituitary secretions in man and this is due to the multiplicity of opiate receptors in pituitary gland cells