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Ke X, Wang L, Zhao Y, Duan L, Deng K, Yao Y, Pan H, Gong F, Zhu H. Serum prolactin levels were positively related to metabolic indexes and disorders in male obese patients. Endocrine 2024; 84:1097-1107. [PMID: 38396200 DOI: 10.1007/s12020-024-03743-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
PURPOSE The role of prolactin (PRL) in glucolipid metabolism was inconsistent, and there were few studies on the metabolic role of PRL in obese patients. The study aims to explore association between PRL level and metabolic disorders in male obese patients. METHODS A retrospective study was conducted. Eighty-nine male patients with obesity were included, and their clinical data were recorded. RESULTS A total of 89 male obese patients were included in this study. Their average age was 24.5 ± 9.0 years and BMI was 42.8 ± 9.1 kg/m2. The average waist circumference and body fat percentage was 129.6 ± 19.6 cm and 42.9 ± 8.0%, respectively. The median prolactin levels were 10.0 ng/ml (range: 3.93-30.1 ng/ml). 79.0% (49/62) of these patients presented with NAFLD and 77.3% (68/88) of them was dyslipidemia. Further, serum prolactin level was positively correlated with BMI (r = 0.225, P = 0.034), body fat percentage (r = 0.326, P = 0.017), ALT (r = 0.273, P = 0.011) and AST (r = 0.245, P = 0.029). Compared with low PRL group (<10 ng/ml), the incidence of morbid obesity and NAFLD was higher in high PRL group (morbid obesity: 71.1% vs 45.5%, P = 0.018 and NAFLD: 91.2% vs 64.3%, P = 0.013). In addition, the risk of NAFLD and morbid obesity in high PRL group (>10 ng/ml) was higher than low PRL group (OR:5.187, 95%CI 1.194-22.544, P = 0.028 and OR: 4.375, 95% CI 1.595-11.994, P = 0.004). The increased risk of NAFLD and morbid obesity in the high PRL group still existed after adjusting for age and Testosterone. CONCLUSION Serum prolactin levels were positively associated with deterioration of metabolic indexes in male obese patients, as well as NAFLD and morbid obesity.
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Affiliation(s)
- Xiaoan Ke
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Linjie Wang
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Yuxing Zhao
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Lian Duan
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Kan Deng
- Department of Neurosurgery, Chinese Academy of Medical Science and Peking Union Medical College, Peking Union Medical College Hospital, 100730, Beijing, China
| | - Yong Yao
- Department of Neurosurgery, Chinese Academy of Medical Science and Peking Union Medical College, Peking Union Medical College Hospital, 100730, Beijing, China
| | - Hui Pan
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Fengying Gong
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Huijuan Zhu
- State Key Laboratory of Complex Severe and Rare Diseases, Chinese Research Center for Behavior Medicine in Growth and Development, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
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Scairati R, Auriemma RS, Del Vecchio G, Di Meglio S, Pivonello R, Colao A. Prolactin effects on the pathogenesis of diabetes mellitus. Eur J Clin Invest 2024; 54:e14190. [PMID: 38470045 DOI: 10.1111/eci.14190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/12/2024] [Accepted: 02/22/2024] [Indexed: 03/13/2024]
Abstract
BACKGROUND Prolactin (PRL) is a pituitary hormone promoting lactation in response to the suckling reflex. Beyond its well-known effects, novel tissue-specific and metabolic functions of PRL are emerging. AIMS To dissect PRL as a critical mediator of whole-body gluco-insulinemic sensitivity. METHODS PubMed-based search with the following terms 'prolactin', 'glucose metabolism', 'type 2 diabetes mellitus', 'type 1 diabetes mellitus', 'gestational diabetes mellitus' was performed. DISCUSSION The identification of the PRL-glucose metabolism network poses the basis for unprecedented avenues of research in the pathogenesis of diabetes mellitus type 1 or 2, as well as of gestational diabetes. In this regard, it is of timely relevance to define properly the homeostatic PRL serum levels since glucose metabolism could be influenced by the circulating amount of the hormone. RESULTS This review underscores the basic mechanisms of regulation of pancreatic β-cell functions by PRL and provides a revision of articles which have investigated the connection between PRL unbalancing and diabetes mellitus. Future studies are needed to elucidate the burden and the role of PRL in the regulation of glucose metabolism and determine the specific PRL threshold that may impact the management of diabetes. CONCLUSION A careful evaluation and context-driven interpretation of PRL levels (e.g., pregnancy, PRL-secreting pituitary adenomas, drug-related hyper- and hypoprolactinemia) could be critical for the correct screening and management of glucometabolic disorders, such as type 1 or 2 as well as gestational diabetes mellitus.
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Affiliation(s)
- Roberta Scairati
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Diabetologia, Andrologia e Nutrizione, Università Federico II di Napoli, Naples, Italy
| | - Renata Simona Auriemma
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Diabetologia, Andrologia e Nutrizione, Università Federico II di Napoli, Naples, Italy
| | - Guendalina Del Vecchio
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Diabetologia, Andrologia e Nutrizione, Università Federico II di Napoli, Naples, Italy
| | - Sara Di Meglio
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Diabetologia, Andrologia e Nutrizione, Università Federico II di Napoli, Naples, Italy
| | - Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Diabetologia, Andrologia e Nutrizione, Università Federico II di Napoli, Naples, Italy
- UNESCO Chair for Health Education and Sustainable Development, University Federico II, Naples, Italy
| | - Annamaria Colao
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Diabetologia, Andrologia e Nutrizione, Università Federico II di Napoli, Naples, Italy
- UNESCO Chair for Health Education and Sustainable Development, University Federico II, Naples, Italy
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Pirchio R, Graziadio C, Colao A, Pivonello R, Auriemma RS. Metabolic effects of prolactin. Front Endocrinol (Lausanne) 2022; 13:1015520. [PMID: 36237192 PMCID: PMC9552666 DOI: 10.3389/fendo.2022.1015520] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/05/2022] [Indexed: 11/23/2022] Open
Abstract
Over the last years, the metabolic role of PRL has emerged. PRL excess is known to promote weight gain, obesity, metabolic syndrome, and impairment in gluco-insulinemic and lipid profiles, likely due to the suppression of physiologic dopaminergic tone. Prolactin receptors and dopamine receptors type 2 have been demonstrated to be expressed on both human pancreatic β- cell and adipocytes, supporting a key role of prolactin and dopamine in peripheral metabolic regulation. Medical treatment with the dopamine agonists bromocriptine and cabergoline has been demonstrated to decrease the prevalence of metabolic syndrome and obesity, and significantly improve gluco-insulinemic and lipid profiles. In hyperprolactinemic men with concomitant hypogonadism, correction of hyperprolactinaemia and testosterone replacement has been proven to restore metabolic impairment. In turn, low prolactin levels have also been demonstrated to exert a detrimental effect on weight gain, glucose and lipid metabolism, thus leading to an increased prevalence of metabolic syndrome. Therefore, PRL values ranging from 25 to 100 mg/L, in absence of other recognizable pathological causes, have been proposed to represent a physiological response to the request for an increase in metabolic activity, and nowadays classify the so-called HomeoFIT- PRL as a promoter of metabolic homeostasis. The current review focuses mainly on the effects of hyperprolactinemia and its control by medical treatment with DAs on the modulation of food intake, body weight, gluco-insulinemic and lipid profile. Furthermore, it provides the latest knowledge about the metabolic impact of hypoprolactinemia.
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Affiliation(s)
- Rosa Pirchio
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, University of Naples Federico II, Naples, Italy
| | - Chiara Graziadio
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, University of Naples Federico II, Naples, Italy
| | - Annamaria Colao
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, University of Naples Federico II, Naples, Italy
- Unesco Chair for Health Education and Sustainable Development, “Federico II” University, Naples, Italy
| | - Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, University of Naples Federico II, Naples, Italy
- Unesco Chair for Health Education and Sustainable Development, “Federico II” University, Naples, Italy
| | - Renata S. Auriemma
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, University of Naples Federico II, Naples, Italy
- *Correspondence: Renata S. Auriemma,
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Impact of Serum Prolactin and Testosterone Levels on the Clinical Parameters of Dry Eye in Pregnant Women. J Ophthalmol 2020; 2020:1491602. [PMID: 32908678 PMCID: PMC7477597 DOI: 10.1155/2020/1491602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/03/2020] [Accepted: 07/18/2020] [Indexed: 11/17/2022] Open
Abstract
Purpose To explore the relationship between serum prolactin, testosterone level, and tear film parameters. The potential impact of these hormones on the health of the ocular surface in pregnant women was evaluated. Methods This was a hospital-based cross-sectional study in which ocular symptoms (Ocular Surface Disease Index (OSDI)), tear function (fluorescein tear breakup time, Schirmer's test 1), corneal and conjunctival staining, meibomian gland (MG) expressibility, and quality of secretion were measured. Lid margin findings including lid notching, thickness, and lid margin telangiectasia were also recorded. Venous blood was collected and the serum concentrations of prolactin and testosterone were determined using ELISA kits. Correlation and multiple linear regression analyses were used to examine predictors of dry eye symptoms and signs. Results A total of 160 pregnant women participated in the study and their mean age was 30.1 ± 4.6 years (range 18-42 years). The correlation analysis indicated that testosterone concentration did not significantly correlate with any of the clinical parameters hence it was not included in the linear regression analysis. However, prolactin serum concentration correlated significantly with Schirmer's test 1. Multiple linear regression was done to predict participants' Schirmer's test 1 score based upon their ocular surface staining score (oxford grading scale), meibomian gland expressibility, meibomian secretion quality, and serum concentration of prolactin. Only predictors that significantly correlated with Schirmer's test 1 in the correlation analysis were included in the linear regression analysis. A significant regression equation was obtained (F (2, 157) = 5.119, p=0.007) with an R square of 0.05. Multiple linear regression analysis revealed that concentration of prolactin (ß coefficient = 0.032, p=0.044) and meibomian gland expressibility scores (ß coefficient = 2.14, p=0.016) were associated with Schirmer's test 1 scores when adjusted for duration of pregnancy. Conclusion The study showed that increased serum prolactin levels have a weak but positive impact on Schirmer's test 1 scores whilst serum testosterone level has no association with the clinical parameters of dry eye in pregnant women.
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Auriemma RS, De Alcubierre D, Pirchio R, Pivonello R, Colao A. Glucose Abnormalities Associated to Prolactin Secreting Pituitary Adenomas. Front Endocrinol (Lausanne) 2019; 10:327. [PMID: 31191454 PMCID: PMC6540784 DOI: 10.3389/fendo.2019.00327] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 05/07/2019] [Indexed: 12/15/2022] Open
Abstract
The pathogenesis of obesity and alterations in glucose profile have been linked to PRL excess, as it is reportedly associated with metabolic syndrome in thereabout one third of patients. In vitro exposure of pancreatic islet to PRL is known to stimulate insulin secretion and β-cell proliferation, and in turn overexpression of PRL in β-cells increases insulin release and β-cell replication. PRL excess has been found to worsen glucose profile because it reduces glucose tolerance and induces insulin resistance either in obese and non-obese patients. To note, pancreatic β-cells and adipocytes widely express dopamine receptors type 2, and dopamine has been hypothesized to play a key role as modulator of insulin and adipose functions. The dopamine agonists bromocriptine and cabergoline significantly improve abnormalities in glucose profile and reduce the prevalence of metabolic syndrome in a remarkable proportion of patients, regardless of whether body weight and PRL status may change. However, in men with hyperprolactinemia complicated by hypogonadism, testosterone replacement can ameliorate insulin resistance and abnormalities in glucose metabolism. Therefore, in patients with PRL-secreting pituitary adenomas control of PRL excess by dopamine agonists is mandatory to improve glucose and insulin abnormalities.
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Auriemma RS, De Alcubierre D, Pirchio R, Pivonello R, Colao A. The effects of hyperprolactinemia and its control on metabolic diseases. Expert Rev Endocrinol Metab 2018; 13:99-106. [PMID: 30058862 DOI: 10.1080/17446651.2018.1434412] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Hyperprolactinaemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with impaired metabolic profile and metabolic syndrome in approximately one third of patients. AREAS COVERED Suppression of dopaminergic tone has been proposed as a potential mechanism responsible for weight gain and metabolic abnormalities in such patients. Dopamine receptor type 2 (D2R) is abundantly expressed on human pancreatic β-cell and adipocytes, suggesting a regulatory role for peripheral dopamine in insulin and adipose functions. Medical treatment with the dopamine-agonists bromocriptine and cabergoline has been shown to significantly improve gluco-insulinemic and lipid profile, also reducing the prevalence of metabolic syndrome. In patients with concomitant hypogonadism, simultaneous correction of both PRL excess and testosterone deficiency is mandatory to improve insulin resistance and metabolic abnormalities. EXPERT COMMENTARY Hyperprolactinemia promotes metabolic alterations. Control of PRL excess by dopamine agonists is mandatory to induce weight loss and to improve metabolic profile, and replacement treatment for concomitant hypogonadism effectively ameliorates insulin resistance and metabolic syndrome.
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Affiliation(s)
- Renata S Auriemma
- a Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia , University of Naples Federico II , Naples , Italy
| | - Dario De Alcubierre
- a Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia , University of Naples Federico II , Naples , Italy
| | - Rosa Pirchio
- a Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia , University of Naples Federico II , Naples , Italy
| | - Rosario Pivonello
- a Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia , University of Naples Federico II , Naples , Italy
| | - Annamaria Colao
- a Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia , University of Naples Federico II , Naples , Italy
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Peony-Glycyrrhiza Decoction for Antipsychotic-Related Hyperprolactinemia in Women With Schizophrenia: A Randomized Controlled Trial. J Clin Psychopharmacol 2016; 36:572-579. [PMID: 27755159 DOI: 10.1097/jcp.0000000000000607] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVES An herbal preparation called peony-glycyrrhiza decoction (PGD) may have the potential in reducing antipsychotic-related hyperprolactinemia (hyperPRL). This double-blind, randomized placebo-controlled study aimed to reevaluate the efficacy of PGD against antipsychotic-related hyperPRL. METHODS Ninety-nine schizophrenic women who were under antipsychotic therapy and had symptomatic hyperPRL were randomly assigned to additional treatment with placebo (n = 50) or PGD (n = 49, 45 g/d) for 16 weeks. The severity of hyperPRL, psychosis, and abnormal involuntary movements was assessed at baseline and weeks 8 and 16 using standard instruments including the Prolactin Related Adverse Event Questionnaire. Blood levels of prolactin (PRL) and related pituitary and sex hormones were measured at the same time points. RESULTS Peony-glycyrrhiza decoction treatment produced a significantly greater reduction of the Prolactin Related Adverse Event Questionnaire score at weeks 8 and 16 and a greater improvement on abnormal involuntary movements at end point compared with placebo, without altering the severity of psychosis. The group treated with PGD showed significantly higher proportion of having overall improvement on hyperPRL symptoms (χ = 4.010, P = 0.045) and menstrual resumption (χ = 4.549, P = 0.033) at week 8 than placebo. Serum PRL levels were similar in the 2 groups. CONCLUSIONS Peony-glycyrrhiza decoction is effective in reducing antipsychotic-related hyperPRL and abnormal involuntary movement symptoms, but no reduction in blood PRL concentrations was observed. The underlying mechanisms of PGD's effects need further investigation (trial registration of NCT01852331 at www.clinicaltrials.gov).
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García-Tornadú I, Ornstein AM, Chamson-Reig A, Wheeler MB, Hill DJ, Arany E, Rubinstein M, Becu-Villalobos D. Disruption of the dopamine d2 receptor impairs insulin secretion and causes glucose intolerance. Endocrinology 2010; 151:1441-50. [PMID: 20147524 DOI: 10.1210/en.2009-0996] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The relationship between antidopaminergic drugs and glucose has not been extensively studied, even though chronic neuroleptic treatment causes hyperinsulinemia in normal subjects or is associated with diabetes in psychiatric patients. We sought to evaluate dopamine D2 receptor (D2R) participation in pancreatic function. Glucose homeostasis was studied in D2R knockout mice (Drd2(-/-)) mice and in isolated islets from wild-type and Drd2(-/-) mice, using different pharmacological tools. Pancreas immunohistochemistry was performed. Drd2(-/-) male mice exhibited an impairment of insulin response to glucose and high fasting glucose levels and were glucose intolerant. Glucose intolerance resulted from a blunted insulin secretory response, rather than insulin resistance, as shown by glucose-stimulated insulin secretion tests (GSIS) in vivo and in vitro and by a conserved insulin tolerance test in vivo. On the other hand, short-term treatment with cabergoline, a dopamine agonist, resulted in glucose intolerance and decreased insulin response to glucose in wild-type but not in Drd2(-/-) mice; this effect was partially prevented by haloperidol, a D2R antagonist. In vitro results indicated that GSIS was impaired in islets from Drd2(-/-) mice and that only in wild-type islets did dopamine inhibit GSIS, an effect that was blocked by a D2R but not a D1R antagonist. Finally, immunohistochemistry showed a diminished pancreatic beta-cell mass in Drd2(-/-) mice and decreased beta-cell replication in 2-month-old Drd2(-/-) mice. Pancreatic D2Rs inhibit glucose-stimulated insulin release. Lack of dopaminergic inhibition throughout development may exert a gradual deteriorating effect on insulin homeostasis, so that eventually glucose intolerance develops.
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Affiliation(s)
- Isabel García-Tornadú
- Instituto de Biología y Medicina Experimental-CONICET, Vuelta de Obligado 2490, Buenos Aires 1428, Argentina.
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Metabolic Syndrome X: A Postmenopausal Woman's Hidden Nemesis. J Women Aging 2008. [DOI: 10.1300/j074v09n01_06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
It has been shown that prolactin (PRL) induces glucose intolerance, hyperinsulinemia and insulin resistance in several animal species. In women with microprolactinomas, the sensitivity to insulin is lower in hyperprolactinemia than in normoprolactinemia. Thirty non-obese women with hyperprolactinemia and 30 healthy non-obese women were included into the study. Age, body weight (bw), height, body mass index (BMI), waist circumference, hip circumference and waist to hip ratio of both patients with hyperprolactinemia and control subjects were not different. Mean serum prolactin level was higher in hyperprolactinemic patients than in control group (84.5 +/- 51.1 ng/ml and 13.8 +/- 5.3 ng/ml respectively, p<0.002). Mean HOMA-(%B) index of hyperprolactinemic patients was higher than in control subjects (121 +/- 49 and 84 +/- 38, respectively, p<0.02). Mean HOMA-(%S) index was lower in hyperprolactinemic patients (56 +/- 39 and 105 +/- 55, respectively, p<0.006). Serum total testosterone, free testosterone, androstenedione, estradiol, cortisol, sex hormone binding globulin and DHEA-S levels in both hyperprolactinemic women and healthy subjects, statistically did not show any difference between the two groups. The present data indicate that hyperprolactinemia is associated with an insulin-resistant state. This resistant state may not be a result of obesity, androgenic hormones, and SHBG or pregnancy. It may be the result of serum free fatty acids (FFA) levels, decrement in the number of insulin receptors (by a down-regulation of insulin receptors) or post-binding defect in insulin action or more.
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Affiliation(s)
- A Tuzcu
- Department of Endocrinology and Metabolism, University of Dicle, School of Medicine, Diyarbakir, Turkey.
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Freemark M, Avril I, Fleenor D, Driscoll P, Petro A, Opara E, Kendall W, Oden J, Bridges S, Binart N, Breant B, Kelly PA. Targeted deletion of the PRL receptor: effects on islet development, insulin production, and glucose tolerance. Endocrinology 2002; 143:1378-85. [PMID: 11897695 DOI: 10.1210/endo.143.4.8722] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
PRL and placental lactogen (PL) stimulate beta-cell proliferation and insulin gene transcription in isolated islets and rat insulinoma cells, but the roles of the lactogenic hormones in islet development and insulin production in vivo remain unclear. To clarify the roles of the lactogens in pancreatic development and function, we measured islet density (number of islets/cm(2)) and mean islet size, beta-cell mass, pancreatic insulin mRNA levels, islet insulin content, and the insulin secretory response to glucose in an experimental model of lactogen resistance: the PRL receptor (PRLR)-deficient mouse. We then measured plasma glucose concentrations after ip injections of glucose or insulin. Compared with wild-type littermates, PRLR-deficient mice had 26-42% reductions (P < 0.01) in islet density and beta-cell mass. The reductions in islet density and beta-cell mass were noted as early as 3 wk of age and persisted through 8 months of age and were observed in both male and female mice. Pancreatic islets of PRLR-deficient mice were smaller than those of wild-type mice at weaning but not in adulthood. Pancreatic insulin mRNA levels were 20-30% lower (P < 0.05) in adult PRLR-deficient mice than in wild-type mice, and the insulin content of isolated islets was reduced by 16-25%. The insulin secretory response to ip glucose was blunted in PRLR-deficient males in vivo (P < 0.05) and in isolated islets of PRLR-deficient females and males in vitro (P < 0.01). Fasting blood glucose concentrations in PRLR-deficient mice were normal, but glucose levels after an ip glucose load were 10-20% higher (P < 0.02) than those in wild-type mice. On the other hand, the glucose response to ip insulin was normal. Our observations establish a physiologic role for lactogens in islet development and function.
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Affiliation(s)
- Michael Freemark
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Ling C, Billig H. PRL receptor-mediated effects in female mouse adipocytes: PRL induces suppressors of cytokine signaling expression and suppresses insulin-induced leptin production in adipocytes in vitro. Endocrinology 2001; 142:4880-90. [PMID: 11606456 DOI: 10.1210/endo.142.11.8514] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PRL has been reported to regulate fat metabolism in several species. We recently reported PRL receptor (PRLR) expression in mouse adipocytes and increased levels of PRLR expression in the adipose tissue of lactating and PRL-transgenic mice compared with controls. These results suggest PRLR-mediated effects in adipose tissue. However, to date most studies have been performed in vivo, and it is unclear whether PRL has direct effects on adipocytes. The PRLR belongs to the cytokine receptor family, and a family of suppressors of cytokine signaling (SOCS) was recently identified. The present study was performed to investigate whether PRL has direct effects on adipocytes. The expression of cytokine-inducible SH2-domain-containing protein (CIS), SOCS-3, and SOCS-2 mRNA and protein was analyzed using ribonuclease protection assay and immunoblotting, respectively. Ovine PRL induced CIS mRNA expression and a combination of oPRL and insulin induced SOCS-3 mRNA expression in adipocytes cultured in vitro for 0-240 min, demonstrating PRLR-mediated direct effects in these cells. Furthermore, CIS, SOCS-3, and SOCS-2 mRNA and protein were all transiently expressed in adipose tissue obtained from female mice stimulated with oPRL (1 microg/g BW) for 0-24 h. In adipose tissue of female mice with endogenously high PRL levels, PRL-transgenic mice, only SOCS-2 expression was increased. The level of SOCS-2 mRNA was also increased in adipose tissue during pregnancy and lactation compared with that in wild-type virgin female mice. A possible reason for increased SOCS-2 expression after prolonged PRL exposure during lactation and in the PRL transgenes could be to restore the sensitivity of adipose tissue to PRL. In addition, the direct effect of PRL on leptin production was investigated in adipocytes cultured in vitro for 6 h. PRL inhibited insulin-induced leptin production in vitro. However, PRL had no effect on leptin production in the absence of insulin. In contrast, serum leptin concentrations were increased in PRL-transgenic females compared with control mice. In conclusion, our results demonstrate functional PRLRs in mouse adipocytes and suggest a role for CIS, SOCS-3, and SOCS-2 in regulating PRL signal transduction in adipose tissue.
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Affiliation(s)
- C Ling
- Department of Physiology, Goteborg University, SE 405 30 Göteborg, Sweden
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Ling C, Kindblom J, Wennbo H, Billig H. Increased resistin expression in the adipose tissue of male prolactin transgenic mice and in male mice with elevated androgen levels. FEBS Lett 2001; 507:147-50. [PMID: 11684088 DOI: 10.1016/s0014-5793(01)02961-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The aim of this study was to investigate the regulation of resistin, a recently identified adipocyte-secreted peptide, in the adipose tissue of prolactin (PRL)-transgenic (tg) mice using ribonuclease protection assay. The level of resistin mRNA increased 3.5-fold in the adipose tissue of untreated male PRL-tg mice compared to controls. However, there was no difference in resistin expression in the adipose tissue of female PRL-tg mice compared to control mice. PRL-tg male mice have elevated serum testosterone levels and we therefore analyzed the effects of testosterone alone on resistin mRNA expression. Furthermore, the effects of elevated androgen levels on PRL receptor (PRLR) mRNA expression in the adipose tissue were investigated. Resistin mRNA increased 2.6-fold in the adipose tissue of control male mice with elevated serum androgen levels. In addition, PRLR mRNA expression was increased in the adipose tissue of male mice with elevated testosterone. These results suggest testosterone to be a regulator of resistin and PRLR mRNA expression in the adipose tissue of male mice.
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Affiliation(s)
- C Ling
- Department of Physiology, Göteborg University, Sweden
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