Search Results (37)

Background: Prolactin receptor (PRLR) signaling affects breastfeeding and potentially breast cancer treatment response. Methods: The prognostic impact of 20 PRLR single nucleotide polymorphisms (SNPs) in relation to adjuvant treatment groups in patients with primary breast cancer (n = 1701, 2002–2016, Sweden) was evaluated. Genomic DNA was genotyped on Illumina OncoArray, and survival analyses with up to 15-year follow-up were performed. Interaction models, adjusted for potential confounders, were created with different adjuvant treatment modalities: chemotherapy, radiotherapy, tamoxifen, and aromatase inhibitors. Results: Five SNPs (rs7734558, rs6860397, rs2962101, rs7732013, and rs4703503) showed interactions with radiotherapy and were utilized to create seven combined genotypes: six unique and one ‘rare’. Patients carrying combined genotype AG/GG/TT/CC/TC or ‘rare’ combinations derived greater benefits from radiotherapy than other patient groups (both HR_adj ≤ 0.29, Bonferroni-adjusted P_int ≤ 0.039). Expression Quantitative Trait Loci (eQTL) analysis revealed that three PRLR SNPs were associated with decreased PRLR expression. To explore potential SNP-associated effects, gene expression and transcriptional networks were analyzed in the METABRIC cohort and indicated that PRLR-low tumors were associated with reduced DNA repair signaling and enhanced anti-tumoral immunity. Conclusions: PRLR merits further evaluation as a putative pharmacogenomic biomarker in relation to radiotherapy for breast cancer patients. Full article

Background: Prolactin (PRL) is a key reproductive hormone that regulates follicular development through endocrine and paracrine mechanisms. However, its specific role in porcine follicular development remains unclear. Methods: In the in vivo experiments, follicular fluid and tissue cells were obtained from small (1–2 mm), medium (3–4 mm), and large (5–6 mm) porcine follicles. PRL levels in follicular fluid were measured by ELISA. The expression levels of genes and proteins related to follicular development were assessed using quantitative real-time PCR (RT-qPCR) and Western blotting (WB). In the in vitro experiments, CCK-8, RT-qPCR, and WB were used to detect the effects of different concentrations (0, 30, and 300 ng/mL) of recombinant porcine prolactin (prPRL) on granulosa cell (GC) proliferation, steroid hormone synthesis, and angiogenesis, and transcriptome sequencing was performed. Results: The PRL concentration was significantly higher in large follicles compared to small and medium follicles. During follicular development, expression levels of PRL, PRL receptor (PRLR), proteolytic enzymes (CTSD, MMP2, MMP14, and BMP-1), and angiogenic factors (VEGFA and FGF-2) increased and then decreased. Moreover, prPRL promoted GC proliferation, increased the expression of PCNA and cyclin D1, upregulated steroidogenesis-related genes CYP11A1 and 3β-HSD, and significantly enhanced the expression of key angiogenic factors VEGFA and FGF-2. RNA-seq analysis identified 226 differentially expressed genes (DEGs), which were mainly enriched in signaling pathways such as the Hippo, JAK/STAT, and Rap1 pathways. Conclusions: PRL may regulate porcine follicle development by affecting cell proliferation and angiogenesis in GCs through the Hippo, JAK/STAT and Rap1 signaling pathways. Full article

Prolactin is a hormone for which actions on the central nervous system such as neurogenesis and neuroprotection have been described by acting on specific receptors. The presence of prolactin receptors in the brain, including the hippocampus, is well documented; however, it is unknown whether these receptors change with age and whether they are related to sex. For this reason, a study of the expression of prolactin receptors, in the short and long isoforms, in the hippocampus of male and female rats has been carried out by qPCR and in situ hybridization, with a densitometric analysis in the following life stages: prepubertal, postpubertal, young adult, adult, and old. The results revealed the greater expression of the long isoform than of the short isoform in males, but not in females, with significant differences between males and females and in the different life stages studied. With significant differences, the highest expression of both isoforms appeared in male rats in the postpubertal stage, and the lowest expression was observed in adult and old animals. In situ hybridization showed differences in the localization of PRLR mRNA expression in CA1, CA3, and DG depending on the age and sex of the rats. The results obtained suggest that hippocampal aging is related to a decrease in prolactin receptors, which helps to better understand brain aging. Full article

A study was designed to explore the possibility of using herbal supplementation to sustain growth performance during heat stress exposure in Kenguri sheep. This 60-day study was conducted on 24 Kenguri ewes (1–2 years old), randomly assigned to four treatment groups (n = 6 per group) as follows: KC (n = 6; Kenguri Control), KHS (n = 6; Kenguri Heat Stress), KCS (n = 6; Kenguri Control and herbal supplement), and KHSS (n = 6; Kenguri Heat Stress and herbal supplement). The herbal mixture of Ocimum sanctum (Tulsi), Emblica officinalis (Amla), Morinda citrifolia (Noni), Withania somnifera (Ashwagandha), and Phyllostachys edulis (Bamboo) was used in this study. The herbal supplement used in the present study was given to the KCS and KHSS groups’ animals in dry powder form at a dose of 0.8 g/Kg BW/Day. All variables were recorded fortnightly, and gene expression analysis was performed at the end of the experiment. The results indicated that the recorded temperature–humidity index (THI) provided thermal comfort for KC and KCS while inducing extremely severe heat stress to the KHS and KHSS groups. Heat stress did not alter the feed intake, while the herbal supplement during heat stress increased the feed intake from day 30 onwards. Furthermore, heat stress significantly (p < 0.001) increased the water intake, while the herbal supplement did not alter the heat stress-induced water intake. In addition, neither heat stress nor herbal supplements influenced the body weight and allometric measurements studied. Furthermore, heat stress significantly (p < 0.01) decreased the level of plasma tri-iodo-thyronine (T₃) and thyroxin (T₄) and had a non-significant effect on plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1), while the herbal supplements significantly (p < 0.01) increased the levels of all these hormones studied. Likewise, in peripheral blood mononuclear cells (PBMCs) the expression patterns of growth hormone receptor (GHR), Insulin-like growth factor 1 (IGF1) and prolactin receptor (PRLR) were significantly (p < 0.001) downregulated during heat stress (0.25, 0.3, and 0.48-fold change, respectively). However, the herbal supplement significantly (p < 0.01) increased the heat stress-induced reduction in the expression pattern of these three genes (0.65, 0.61, and 0.61-fold change, respectively). Therefore, from this study, it could be concluded that although the herbal supplements did not bring positive changes in body weight and allometric measurements, it still had a beneficial impact on the endocrinology and genes governing growth performance in Kenguri ewes. Thus, the herbal feed additive used in the study shows promise for relieving heat stress in Kenguri ewes. Full article

This study designed three sgRNAs (sgRNA139, sgRNA128, and sgRNA109) targeting the prolactin gene receptor (PRLR) in fetal cattle, utilized Cas9 to cleave endogenous DNA, and screened stable cell lines for somatic cell nuclear transfer experiments to investigate the impact of different editing sites on embryonic development. The results showed that sgRNA139 had the highest cleavage efficiency (Fcut = 0.65, Indels = 42.19%), while sgRNA109 had the lowest (Fcut = 0.45, Indels = 35.31%). No significant differences were observed in cell growth status after electroporation (p > 0.05), and the transfection efficiency exceeded 90% after five days of culture. In the evaluation of key embryonic development indicators, sgRNA109 significantly reduced the cleavage rate and blastocyst rate (p < 0.01), whereas sgRNA139 showed no significant effect on the cleavage rate (p > 0.05), but its blastocyst rate was slightly lower than that of the control group (p > 0.05). This study demonstrates that highly specific sgRNAs and stable edited cell lines used as donor cells can significantly regulate the later stages of embryonic development. This study not only provides new experimental evidence for the functional study of the PRLR but also lays an important theoretical foundation for the innovation of molecular breeding technologies in dairy cattle. Full article

Medicinal plants and natural compounds have been considered alternative therapeutic options for counteracting postmenopausal disorders thanks to their different concomitant effects, including antioxidant and anti-inflammatory properties and the regulation of hormone activity. It is important to highlight that the efficacy of medicinal plants and natural compounds increases when used in combination, thus making the development of herbal formulations rational. Therefore, the present study aimed to evaluate the phytochemical and pharmacological properties of an innovative formulation consisting of resveratrol and water extracts from Equisetum arvense, Crateagus curvisepala, Vitex agnus-castus, and Glycine max. The phenolic composition and radical scavenger properties were evaluated using chromatographic and colorimetric (ABTS) methods, whilst the limits of biocompatibility were assessed through allelopathy, the Artemia salina (brine shrimp) lethality test, and Daphnia magna cardiotoxicity assay. The protective effects were evaluated on C2C12 cell lines exposed to the pro-oxidant stimulus, which consisted of hydrogen peroxide. The gene expression of estrogen 1 (ESR1, also known as ERα) and prolactin (PRLR) receptors, interleukin 6 (IL-6), tumor necrosis factor α (TNFα), and receptor activator of nuclear factor kappa-Β ligand (RANKL) was measured. The results of the phytochemical analysis showed that the main phytochemicals were hydroxycinnamic and phenolic acids, in particular coumaric acid (7.53 µg/mL) and rosmarinic acid (6.91 µg/mL), respectively. This could explain the radical scavenger effect observed from the 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. According to the ecotoxicological models’ results, the formulation was revealed to be non-toxic, with a LC₅₀ value > 1 mg/mL. Therefore, a biocompatible concentration range (200–1000 µg/mL) was used in C2C12 cells, where the formulation blunted the hydrogen peroxide-induced upregulation of TNFα, IL-6, RANKL, ESR1, and PRLR. Overall, the results of this study corroborate the use of the formulation for facing the oxidative stress and inflammation, which forms the basis of the osteoclastogenic process. Full article

In our previous study, we found that changes in plasma prolactin (PRL) concentration were significantly associated with heat stress in dairy cows, and that PRL plays an important role in milk performance. Microarray sequencing revealed that thyrotropin releasing hormone (TRH) and prolactin receptor (PRLR), two genes important for PRL expression or function, may affect milk performance, reproduction, and heat stress response in dairy cattle. In this study, we further validated the genetic effects of the three genes in Chinese Holsteins. The potential variants within the three genes were first detected in 70 Chinese Holstein bulls and then screened in 1152 Chinese Holstein cows using the KASP (Kompetitive allele-specific PCR) method. In total, 42 variants were identified. Further, 13 SNPs were retained for KASP genotyping, including 8 in TRH, 3 in PRL, and 2 in PRLR. Using SNP-based association analyses, the multiple significant (p < 0.05) associations of these 13 SNPs with milk performance, reproduction, and heat stress response traits were found in the Holstein population. Furthermore, linkage disequilibrium analysis found a haplotype block in each of the TRH and PRL genes. Haplotype-based association analyses showed that haplotype blocks were also significantly (p < 0.05) associated with milk performance, reproduction, and heat stress response traits. Collectively, our results identified the genetic associations of TRH, PRL, and PRLR with milk performance, reproduction, and heat stress response traits in dairy cows, and found the important roles of SNP g.55888602A/C and g.55885455A/G in TRH in all traits, providing important molecular markers for genetic selection of high-yielding dairy cows. Full article

The Chinese tongue sole (Cynoglossus semilaevis) is a marine flatfish of significant economic value, characterized by pronounced female-biased sexual size dimorphism (SSD). Sexual differences of cell number and gene expression within the PIT-1 lineage of the pituitary gland may be crucial for interpreting the female-biased SSD of C. semilaevis. Among hormones secreted by PIT-1 cell lineage, growth hormone (gh), prolactin (prl), prolactin 2 (prl2), and somatolactin (sl) comprise a gene family within the extensive superfamily of class-1 helical cytokines. To better understand the function of the gh/prl/sl in teleost SSD, we firstly identified five genes of the gh/prl/sl family (gh, sl, prl, prl2a, and prl2b) and their receptors (ghra, ghrb, prlra, prlrb, and prlr-like) from C. semilaevis at the genome-wide level. Phylogenetic analyses revealed that the gh/prl/sl family and their receptors were each clustered into five distinct groups. More microsatellites were revealed in the intron 2 of gh gene of female rather than the male and pseudo-male individuals, which is positively correlated with its sexual expression pattern. Interaction network prediction indicated that gh, prl, and sl may collectively contribute to individual growth and development. A FRET experiment showed that ghra can act as a receptor for sl. Additionally, the transcripts of the gh/prl/sl family and their receptors exhibited varying abundances in the pituitary, brain, gonad, and liver of both female and male C. semilaevis, with most ligands showing the highest abundance in the female pituitary. Furthermore, gh and sl were found to be maternally expressed. The knock-down of gh, prl, and sl in the pituitary cells could lead to the expression change of igf1, c-fos, and sos2. This study provided a foundation for further functional characterization of the gh/prl/sl gene family, contributing to a deeper understanding of the growth and reproductive mechanisms in C. semilaevis. Full article

Breast cancer (BC) is the most common cancer in women, and a higher level of prolactin-induced protein (PIP) is associated with better responses to adjuvant chemotherapy. The signal transducer and activator of transcription 5 (STAT5) is a potential regulator of the PIP gene. Prolactin (PRL) and its receptor (PRLR) activate JAK2/STAT5 signaling in BC, which is modulated by inhibitors like suppressors of cytokine signaling (SOCS) proteins and protein inhibitors of activated STAT (PIAS). Using real-time PCR and immunohistochemistry, we studied the relationship between PIP and STAT5 inhibitors in BC. Our findings indicated that PIP and STAT5 levels decrease with a higher tumor grade, size, and tumor/nodes/metastasis (TNM) clinical stage, while nuclear PIAS3 levels increase with tumor progression. Both STAT inhibitors are linked to estrogen and progesterone receptor status. Notably, STAT5 correlates positively with PIP, SOCS3, and PIAS3, suggesting that it may be a favorable prognostic factor. Among the STAT inhibitors, only nuclear PIAS3 expression correlates with PIP. In vitro studies indicated that silencing PIAS3 in T47D cells does not affect PIP expression or sensitivity to doxorubicin (DOX), but T47D control cells with a higher PIP expression are more sensitive to DOX, highlighting the need for further investigation into these mechanisms. Full article

The aim of the present study was to investigate the phenolic composition and the efficacy of an innovative formulation based on Mg, Vitamin B6, and water extracts from Vitex agnus-castus, Crocus sativus, Melissa officinalis, Betula pendula, and Betula pubescens developed as an effective tool to face neuroinflammation and depression symptoms occurring in premenstrual syndrome (PMS). The formulation was analyzed through colorimetric and liquid chromatography methods for determining the content in phenols and flavonoids. Additionally, scavenging/reducing properties were investigated via 2,2-diphenyl-1-picrylhydrazyl (DPPH,) 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and horseradish peroxidase assays. The biocompatible limits were determined via allelopathy, the brine shrimp lethality test, and Daphnia magna cardiotoxicity assay. The formulation was then assayed in an experimental model constituted by isolated mouse cortex specimens exposed to K⁺ 60 mM Krebs–Ringer buffer, a toxic depolarizing stimulus able to reproduce the burden of inflammation/oxidative stress and the increased serotonin (5-hydroxytryptamine, 5-HT) impoverishment occurring in different neurological and psychiatric conditions, including depression. The results of the phytochemical analysis showed that the formulation is rich in benzoic acids, namely gentisic acid (155.31 µg/mL) and phenylethanoid compounds, namely hydroxytyrosol (39.79 µg/mL) that support the antioxidant effects measured via DPPH (IC₅₀: 1.48 mg/mL), ABTS (IC₅₀: 0.42 mg/mL), and horseradish peroxidase (IC₅₀: 2.02 mg/mL) assays. The ecotoxicological models indicated the formulation as non-toxic, permitting the identification of a biocompatible concentration (1000 µg/mL) to be used in isolated mouse cortex exposed to K⁺ 60 mM Krebs–Ringer buffer. In this model, the gene expression of cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), estrogen receptor-1 (ESR1), prolactin receptor (PRLR), brain-derived neurotrophic factor (BDNF), and serotonin transporter (SERT) was determined by real-time PCR. In the isolated mouse cortex, the formula reduced COX-2, IL-6, SERT, ESR1, and PRLR gene expression and increased BDNF and IL-10 gene expression. Overall, the study corroborated the use of the formulation as an innovative tool to contrast inflammation, oxidative stress, and neurotransmitter impairment associated with PMS. Full article

This review examines genetic markers associated with litter size in goats, a key reproductive trait impacting productivity in small ruminant farming. Goats play a vital socioeconomic role in both low- and high-income regions; however, their productivity remains limited due to low reproductive efficiency. Litter size, influenced by multiple genes and environmental factors, directly affects farm profitability and sustainability by increasing the output per breeding cycle. Recent advancements in genetic research have identified key genes and pathways associated with reproductive traits, including gonadotropin-releasing hormone (GnRH), inhibin (INHAA), Kit ligand (KITLG), protein phosphatase 3 catalytic subunit alpha (PPP3CA), prolactin receptor (PRLR), POU domain class 1 transcription factor 1 (POU1F1), anti-Müllerian hormone (AMH), bone morphogenetic proteins (BMP), growth differentiation factor 9 (GDF9), and KISS1 and suppressor of mothers against decapentaplegic (SMAD) family genes, among others. These genes regulate crucial physiological processes such as folliculogenesis, hormone synthesis, and ovulation. Genome-wide association studies (GWASs) and transcriptomic analyses have pinpointed specific genes linked to increased litter size, highlighting their potential in selective breeding programs. By incorporating genomic data, breeding strategies can achieve higher selection accuracy, accelerate genetic gains, and improve reproductive efficiency. This review emphasizes the importance of genetic markers in optimizing litter size and promoting sustainable productivity in goat farming. Full article

Growth hormone (GH) signaling is essential for heart development. Both GH deficiency and excess raise cardiovascular risk. Human (h) and mouse (m) GH differ structurally and functionally: hGH binds both the GH receptor (GHR) and prolactin receptor (PRLR), whereas mGH binds only GHR; thus, there is the potential for differential effects. We generated transgenic (hGH-TG) mice that produce pituitary hGH in response to hypothalamic signaling. These mice grow at the same rate as mGH-expressing wild-type (mGH-WT) mice but are smaller and have higher body fat. Echocardiography was used here to compare hGH-TG and mGH-WT mouse hearts. Male hGH-TG mice show a 48% lower left ventricular mass, 36% lower stroke volume, and 48% reduced cardiac output, resembling GH deficiency. Diastolic dysfunction, restrictive ventricular filling, and lower heart rate are suggested in hGH-TG mice. No significant differences in ejection fraction or fractional shortening were observed, even after high-fat diet (HFD) stress. HFD did not affect RNA markers of cardiac damage, although a possible association between B-type natriuretic peptide RNA levels and heart rate was detected. These observations suggest that diastolic dysfunction related to hGH and/or low GH might be offset by a lower heart rate, while structural changes precede functional effects. Full article

Prolactin (PRL) has recently been found to play a role in lipid metabolism in addition to its traditional roles in lactation and reproduction. However, the effects of PRL on lipid metabolism in liver and adipose tissues are unclear. Therefore, we aimed to study the role of PRL on lipid metabolism in goats. Twenty healthy eleven-month-old Yanshan cashmere goats with similar body weights (BWs) were selected and randomly divided into a control (CON) group and a bromocriptine (BCR, a PRL inhibitor, 0.06 mg/kg, BW) group. The experiment lasted for 30 days. Blood was collected on the day before BCR treatment (day 0) and on the 15th and 30th days after BCR treatment (days 15 and 30). On day 30 of treatment, all goats were slaughtered to collect their liver, subcutaneous adipose, and perirenal adipose tissues. A portion of all collected tissues was stored in 4% paraformaldehyde for histological observation, and another portion was immediately stored in liquid nitrogen for RNA extraction. The PRL inhibition had inconclusive effects found on BW and average daily feed intake (ADFI) in goats (p > 0.05). PRL inhibition decreased the hormone-sensitive lipase (HSL) levels on day 30 (p < 0.05), but the effects were inconclusive on days 0 and 15. PRL inhibition had inconclusive effects found on total cholesterol (TCH), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fatty acid synthase (FAS), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), and acetyl-CoA carboxylase (ACC) on days 0, 15, and 30 (p > 0.05). Furthermore, hematoxylin–eosin (HE) staining of the liver, subcutaneous adipose, and perirenal adipose sections showed that PRL inhibition had inconclusive effects on the pathological changes in their histomorphology (p > 0.05), but measuring adipocytes showed that the area of perirenal adipocytes decreased in the BCR group (p < 0.05). The qPCR results showed that PRL inhibition increased the expression of PRL, long-form PRL receptor (LPRLR), and short-form PRL receptor (SPRLR) genes, as well as the expression of genes related to lipid metabolism, including sterol regulatory element binding transcription factor 1 (SREBF1); sterol regulatory element binding transcription factor 2 (SREBF2); acetyl-CoA carboxylase alpha (ACACA); fatty acid synthase (FASN); 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR); 7-dehydrocholesterol reductase (DHCR7); peroxisome proliferator-activated receptor gamma (PPARG); and lipase E, hormone-sensitive type (LIPE) in the liver (p < 0.05). In the subcutaneous adipose tissue, PRL inhibition increased SPRLR gene expression (p < 0.05) and decreased the expression of genes related to lipid metabolism, including SREBF1, SREBF2, ACACA, PPARG, and LIPE (p < 0.05). In the perirenal adipose tissue, the inhibition of PRL decreased the expression of the PRL, SREBF2, and HMGCR genes (p < 0.05). In conclusion, the inhibition of PRL decreases the serum HSL levels in cashmere goats; the effects of PRL on lipid metabolism are different in different tissues; and PRL affects lipid metabolic activity by regulating different PRLRs in liver and subcutaneous adipose tissues, as well as by decreasing the expression of the PRL, SREBF2, and HMGCR genes in perirenal adipose tissue. Full article

Yanshan Cashmere bucks are seasonal breeding animals and an important national genetic resource. This study aimed to investigate the involvement of prolactin (PRL) in the epididymal function of bucks. Twenty eleven-month-old Cashmere bucks were randomly divided into a control (CON) group and a bromocriptine (BCR, a prolactin inhibitor, 0.06 mg/kg body weight (BW)) treatment group. The experiment was conducted from September to October 2020 in Qinhuangdao City, China, and lasted for 30 days. Blood was collected on the last day before the BCR treatment (day 0) and on the 15th and 30th days after the BCR treatment (days 15 and 30). On the 30th day, all bucks were transported to the local slaughterhouse, where epididymal samples were collected immediately after slaughter. The left epididymis was preserved in 4% paraformaldehyde for histological observation, and the right epididymis was immediately preserved in liquid nitrogen for RNA sequencing (RNA-seq). The results show that the PRL inhibitor reduced the serum PRL and estradiol (E2) concentrations (p < 0.05) and tended to decrease luteinizing hormone (LH) concentrations (p = 0.052) by the 30th day, but no differences (p > 0.05) occurred by either day 0 or 15. There were no differences (p > 0.05) observed in the follicle-stimulating hormone (FSH), testosterone (T), and dihydrotestosterone (DHT) concentrations between the two groups. The PRL receptor (PRLR) protein was mainly located in the cytoplasm and intercellular substance of the epididymal epithelial cells. The PRL inhibitor decreased (p < 0.05) the expression of the PRLR protein in the epididymis. In the BCR group, the height of the epididymal epithelium in the caput and cauda increased, as did the diameter of the epididymal duct in the caput (p < 0.05). However, the diameter of the cauda epididymal duct decreased (p < 0.05). Thereafter, a total of 358 differentially expressed genes (DEGs) were identified in the epididymal tissues, among which 191 were upregulated and 167 were downregulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that ESR2, MAPK10, JUN, ACTL7A, and CALML4 were mainly enriched in the estrogen signaling pathway, steroid binding, calcium ion binding, the GnRH signaling pathway, the cAMP signaling pathway, and the chemical carcinogenesis–reactive oxygen species pathway, which are related to epididymal function. In conclusion, the inhibition of PRL may affect the structure of the epididymis by reducing the expression of the PRLR protein and the secretion of E2. ESR2, MAPK10, JUN, ACTL7A, and CALML4 could be the key genes of PRL in its regulation of epididymal reproductive function. Full article

Background and Objectives: Hyperprolactinemia, as a potential side-effect of some antipsychotic medications, is associated with decreased bone density and an increased risk of fractures. This study investigates whether calcium and vitamin D supplementation affects prolactin receptor (Prlr) gene expression in the duodenum, vertebrae, and kidneys of female rats with sulpiride-induced hyperprolactinemia. Materials and Methods: Twenty-one-week-old female Wistar rats were assigned to three groups: Group S consisted of ten rats who received sulpiride injections (10 mg/kg) twice daily for 6 weeks; Group D (10 rats) received daily supplementation of 50 mg calcium and 500 IU vitamin D along with sulpiride for the last 3 weeks; and Group C consisting of seven age-matched nulliparous rats serving as a control group. Real-time PCR was used to assess Prlr gene expression in the duodenum, vertebrae, and kidneys. Results: In Group S, Prlr gene expression was notably decreased in the duodenum (p < 0.01) but elevated in the vertebrae and kidneys compared to Group C. Conversely, Group D exhibited significantly increased Prlr expression in the duodenum (p < 0.01) alongside elevated expression in the vertebrae and kidneys. Conclusions: In sulpiride-induced hyperprolactinemia, decreased Prlr gene expression in the duodenum may lead to reduced intestinal calcium absorption. Consequently, prolactin may draw calcium from the skeletal system to maintain calcium balance, facilitated by increased Prlr gene expression in the vertebrae. However, vitamin D supplementation in sulpiride-induced hyperprolactinemia notably enhances Prlr gene expression in the duodenum, potentially ameliorating intestinal calcium absorption and mitigating adverse effects on bone health. Full article