There is considerable evidence that mu opioid receptors are involved in the regulation of anterior pituitary function. For example, in nonhuman primates and humans, mu agonists generally increase prolactin (PRL) levels. In contrast, mu antagonists decrease or have no effect on PRL levels. The goal of this study was to assess the potential utility of cumulative-dosing procedures to evaluate the endocrine effects of mu opioid receptor ligands. The effects of single and multiple, cumulative doses of the mu agonist heroin and the mu-selective antagonist quadazocine on PRL levels were investigated in four male rhesus monkeys. Cumulative dose-response curves were determined by infusing increasing drug doses at 60 min intervals over 290 min. Blood samples for PRL analysis were collected at 25 and 50 min after each cumulative infusion. Samples were collected at similar time points following single drug dose administration. Heroin (0.01-0.32 mg/kg, IV) administration dose-dependently increased PRL levels. Maximum levels of heroin-induced PRL levels were equivalent after single and cumulative doses. Quadazocine alone (0.032-1.0 mg/kg, IM) did not alter PRL levels significantly. However, quadazocine (0.1 mg/kg, IM) antagonized heroin-stimulated increases in PRL levels and produced a significant rightward shift in the heroin dose-effect curve. These data suggest that a cumulative-dosing procedure similar to that used in behavioral pharmacology may be useful to study the endocrine pharmacology of mu opioids in rhesus monkeys.
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http://dx.doi.org/10.1016/s0306-4530(01)00053-1 | DOI Listing |
Biomedicines
December 2024
Clinical Division of Gynecologic Endocrinology and Reproductive Medicine, Medical University of Vienna, A-1090 Vienna, Austria.
Gender-affirming hormone therapy (GAHT) is known to influence the lipid profiles of trans men and transmasculine individuals. Recent data show that moderate prolactin (PRL) elevations might exert beneficial metabolic effects ("HomeoFIT-PRL model"). The aim of this study is to investigate changes in PRL levels and possible associations between PRL and lipid profiles in this population after a year of GAHT.
View Article and Find Full Text PDFTheriogenology
January 2025
Department of Clinical Sciences, College of Veterinary Medicine, Qassim University, Saudi Arabia. Electronic address:
Pseudopregnancy is the development of signs of pregnancy in the absence of an embryo or fetus. The objectives of this study were to characterize pseudopregnancy in dromedary camels, determine its prevalence in camel farms and practice, identify associated risk factors, and describe its clinical and hormonal properties. The prevalence of pseudopregnancy on 100 camel farms with 4264 total female camels was determined to be 2.
View Article and Find Full Text PDFJ Clin Res Pediatr Endocrinol
January 2025
Department of Pediatric Endocrinology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.
Prolactinomas are the most common hormone-secreting pituitary adenomas in adolescents. Dopamine agonists (DA) are used as first-line medical treatment. DAs are associated with an array of physical side effects; however, impulse control disorders (ICDs), such as pathological gambling (PG), have also been reported in adults.
View Article and Find Full Text PDFFASEB J
January 2025
Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
This study aimed to investigate the effects of electroacupuncture (EA) at specific acupoints (DU20 and ST36) and different frequencies (2 and 100 Hz) on brain regions associated with trigeminal neuralgia, anxiety, and depression. Chronic trigeminal neuralgia was induced by the chronic constriction of the infraorbital nerve (CION). Anxiety and depression were assessed through behavioral tests.
View Article and Find Full Text PDFAm Heart J Plus
January 2025
University of Pittsburgh Medical Center, Pittsburgh, PA, United States of America.
Objective: Evaluate the relationship of cathepsin-D (CD) on disease severity and clinical outcomes for women with peripartum cardiomyopathy.
Background: Cathepsin-D is a protease released during oxidative stress that cleaves prolactin (PRL) generating a 16 kDa fragment that is pro-apoptotic, anti-angiogenic, and has been implicated in the pathogenesis of peripartum cardiomyopathy (PPCM).
Methods: In 99 women with newly diagnosed PPCM enrolled in the Investigation in Pregnancy Associated Cardiomyopathy (IPAC) study, CD levels were assessed by ELISA from serum obtained at study entry.
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