Prolactin alters blood pressure by modulating the activity of endothelial nitric oxide synthase

Sacubitril/Valsartan Alleviates Cardiac Remodeling and Dysfunction in L-NAME-Induced Hypertension and Hypertensive Heart Disease

There is ample evidence on the benefit of angiotensin receptor-neprilysin inhibitors (ARNIs) in heart failure, yet data regarding the potential protective action of ARNIs in hypertensive heart disease are sparse. The aim of this study was to show whether an ARNI exerts a protective effect in a model of Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertension with a hypertensive heart and to compare this potential benefit with an angiotensin-converting enzyme inhibitor, captopril. Five groups of adult male Wistar rats were studied (14 per group) for four weeks: untreated controls; ARNI (68 mg/kg/day); L-NAME (40 mg/kg/day); L-NAME treated with ARNI; and L-NAME treated with captopril (100 mg/kg/day). L-NAME administration induced hypertension, accompanied by increased left ventricular (LV) weight and fibrotic rebuilding of the LV in terms of increased concentration and content of hydroxyproline in insoluble collagen and in total collagen and with a histological finding of fibrosis. These alterations were associated with a compromised systolic and diastolic LV function. Treatment with either an ARNI or captopril reduced systolic blood pressure (SBP), alleviated LV hypertrophy and fibrosis, and prevented the development of both systolic and diastolic LV dysfunction. Moreover, the serum levels of prolactin and prolactin receptor were reduced significantly by ARNI and slightly by captopril. In conclusion, in L-NAME-induced hypertension, the dual inhibition of neprilysin and AT1 receptors by ARNI reduced SBP and prevented the development of LV hypertrophy, fibrosis, and systolic and diastolic dysfunction. These data suggest that ARNI could provide protection against LV structural remodeling and functional disorders in hypertensive heart disease.

Alternations of Blood Pressure Following Surgical or Drug Therapy for Prolactinomas

Several subtypes of pituitary neuroendocrine tumors (PitNETs), such as acromegaly and Cushing's disease, can result in hypertension. However, whether prolactinoma is associated with this complication remains unknown. Moreover, the effect of treatment with surgery or drugs on blood pressure (BP) is unknown. Herein, a retrospective study reviewed 162 patients with prolactinoma who underwent transsphenoidal surgery between January 2005 and December 2022. BP measurements were performed 1 day before and 5 days after surgery. Accordingly, patients' medical characteristics were recorded. In addition, in situ rat and xenograft nude-mice prolactinoma models have been used to mimic prolactinoma. In vivo BP and serum prolactin (PRL) levels were measured after cabergoline (CAB) administration in both rats and mice. Our data suggest that surgery can effectively decrease BP in prolactinoma patients with or without hypertension. The BP-lowering effect was significantly associated with several variables, including age, sex, disease duration, tumor size, invasion, dopamine agonists (DAs)-resistance, recurrence, and preoperative PRL levels. Moreover, in situ and xenograft prolactinomas induced BP elevation, which was alleviated by CAB treatment without and with a statistical difference in rats and mice, respectively. Thus, surgery or CAB can decrease BP in prolactinoma, indicating that pre- and postoperative BP management becomes essential.

The role of maternal hormones in regulating autonomic functions during pregnancy

Offspring development relies on numerous physiological changes that occur in a mother's body, with hormones driving many of these adaptations. Amongst these, the physiological functions controlled by the autonomic nervous system are required for the mother to survive and are adjusted to meet the demands of the growing foetus and to ensure a successful birth. The hormones oestrogen, progesterone, and lactogenic hormones rise significantly during pregnancy, suggesting they may also play a role in regulating the maternal adaptations linked to autonomic nervous system functions, including respiratory, cardiovascular, and thermoregulatory functions. Indeed, expression of pregnancy hormone receptors spans multiple brain regions known to regulate these physiological functions. This review examines how respiratory, cardiovascular, and thermoregulatory functions are controlled by these pregnancy hormones by focusing on their action on central nervous system circuits. Inadequate adaptations in these systems during pregnancy can give rise to several pregnancy complications, highlighting the importance in understanding the mechanistic underpinnings of these changes and potentially identifying ways to treat pregnancy-associated afflictions using hormones.

Endothelial nitric oxide synthase (eNOS) S1176 phosphorylation status governs atherosclerotic lesion formation

Objective

We have previously demonstrated the in vivo importance of the Akt-eNOS substrate-kinase relationship, as defective postnatal angiogenesis characteristic of global Akt1-null mice is rescued when bred to 'gain-of-function' eNOS S1176D mutant mice. While multiple studies support the vascular protective role of endothelial NO generation, the causal role of Akt1-dependent eNOS S1176 phosphorylation during atherosclerotic plaque formation is not yet clear.

Approach and results

We herein bred congenic 'loss-of-function' eNOS S1176A and 'gain-of-function' eNOS S1176D mutant mice to the exacerbated atherogenic Akt1-/-; ApoE-/- double knockout mice to definitively test the importance of Akt-mediated eNOS S1176 phosphorylation during atherogenesis. We find that a single amino acid substitution at the eNOS S1176 phosphorylation site yields divergent effects on atherosclerotic plaque formation, as an eNOS phospho-mimic aspartate (D) substitution at S1176 leads to favorable lipid profiles and decreased indices of atherosclerosis, even when on a proatherogenic Akt1 global deletion background. Conversely, mice harboring an unphosphorylatable mutation to alanine (S1176A) result in increased plasma lipids, increased lesion formation and cellular apoptosis, phenocopying the physiological consequence of eNOS deletion and/or impaired enzyme function. Furthermore, gene expression analyses of whole aortas indicate a combinatorial detriment from NO deficiency and Western Diet challenge, as 'loss-of-function' eNOS S1176A mice on a Western Diet present a unique expression pattern indicative of augmented T-cell activity when compared to eNOS S1176D mice.

Conclusions

By using genetic epistasis approaches, we conclusively demonstrate that Akt-mediated eNOS S1176 phosphorylation and subsequent eNOS activation remains to be the most physiologically relevant method of NO production to promote athero-protective effects.

Metabolic Abnormalities, Inflammatory Markers and Endothelial Dysfunction in Hyperprolactinemia due to Prolactinoma before and after Normalization of Serum Prolactin: A Prospective Case Control Study

Background

Hyperprolactinemia is associated with obesity, dyslipidemia, insulin resistance, and low-grade inflammation which may promote endothelial dysfunction (EnD). Limited work has been done on EnD in prolactinomas and we, therefore, studied serum markers of inflammation and EnD in patients with prolactinomas before and after treatment with dopamine agonists.

Methodology

Fifty-six treatment naïve patients with prolactinomas and fifty-three (apparently healthy age and sex-matched) controls were enrolled in the study and subjected to clinical assessment and laboratory investigations including blood glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, urea, creatinine, uric acid, erythrocyte sedimentation rate (ESR), highly sensitive C-reactive protein (hsCRP) and markers of EnD i.e., intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Patients were treated with a dopamine agonist (cabergoline) and parameters (like ESR, hsCRP, ICAM-1, and VCAM-1) were measured at 12 weeks.

Results

The majority of the patients (84%) were female, more than half (52%) had metabolic syndrome and over a third (36%) were obese. Blood glucose fasting, HbA1c, lipid fractions, ESR, hsCRP, ICAM-1, and VCAM-1 were significantly higher in patients than in controls. Median ICAM-1 was 1331.95 ng/ml (IQR 803.43-1825.99) in patients vs 753.04 ng/ml (IQR 402.04-871.55) in controls, P < 0.001 and median VCAM-1in patients was 971.35 ng/ml (IQR 695.03-1285.23) as against 634.56 ng/ml (IQR 177.49-946.50) in controls, p0.001. Serum ICAM-1 and VCAM-1 correlated positively with hsCRP. On multivariate regression analysis, serum hsCRP was the only significant predictor of change in ICAM-1 and VCAM-1. Normalization of serum PRL with CAB resulted in a significant decrease in metabolic parameters, ESR, hsCRP, ICAM-1, and VCAM-1.

Conclusion

Hyperprolactinemia because of prolactinoma is associated with EnD secondary to systemic inflammation and metabolic abnormalities which improve after treatment with DA.

Therapeutic potential of traditional Chinese medicine in atherosclerosis: A review

Atherosclerosis is the onset of endothelial cell damage and is characterized by abnormal accumulation of fibrinogen and lipid in large and middle arteries. Recent researches indicate that traditional Chinese medicine including Notoginseng Radix et Rhizoma, Astragali Radix, Salviae Miltiorrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, Fructus Crataegi, Glycyrrhizae Radix et Rhizoma, Polygoni Multiflori Radix, Fructus Lycii, and Coptidis Rhizoma have therapeutic effects on atherosclerosis. Furthermore, the pharmacological roles of these kinds of traditional Chinese medicine in atherosclerosis refer to endothelial function influences, cell proliferation and migration, platelet aggregation, thrombus formation, oxidative stress, inflammation, angiogenesis, apoptosis, autophagy, lipid metabolism, and the gut microbiome. Traditional Chinese medicine may serve as potential and effective anti-atherosclerosis drugs. However, a critical study has shown that Notoginseng Radix et Rhizoma may also have toxic effects including pustules, fever, and elevate circulating neutrophil count. Further high-quality studies are still required to determine the clinical safety and efficacy of traditional Chinese medicine and its active ingredients.

The role of prolactin/vasoinhibins in cardiovascular diseases

Prolactin (PRL) is a polypeptide hormone that is mainly synthesized and secreted by the lactotroph cells of the pituitary. There are two main isoforms of PRL: 23-kDa PRL (named full-length PRL) and vasoinhibins (including 5.6-18 kDa fragments). Both act as circulating hormones and cytokines to stimulate or inhibit vascular formation at different stages and neovascularization, including endothelial cell proliferation and migration, protease production, and apoptosis. However, their effects on vascular function and cardiovascular diseases are different or even contrary. In addition to the structure, secretion regulation, and signal transduction of PRL/vasoinhibins, this review focuses on the pathological mechanism and clinical significance of PRL/vasoinhibins in cardiovascular diseases.

Postpartum Assessment of the Correlation between Serum Hormone Levels of Estradiol, Progesterone, Prolactin and ß-HCG and Blood Pressure Measurements in Pre-Eclampsia Patients

Background: Preeclampsia is a pregnancy-related hypertensive disease. Aberrant hormone levels have been implicated in blood pressure disorders. This study investigated the association of postpartum maternal serum hormone levels of estradiol, progesterone, prolactin, and ß-HCG with poorer PE-related complications including arterial hypertension. Methods: Thirty patient women with preeclampsia, and twenty women with uncomplicated pregnancy were included in this study. Serum levels of estradiol, progesterone, prolactin, and ß-HCG were determined immediately after delivery, and on the first and third postpartum days by means of ECLIA. Results: Compared with normal pregnancy cases, preeclampsia cases had higher serum levels of ß-HCG levels on Day-0 (319%), of progesterone on Day-0 (207%) and Day-1 (178%), and of estradiol on Day-1 (187%) and Day-3 (185%). Increased prolactin levels were positively associated with disease severity and estradiol and progesterone levels were decreased in poorer preeclampsia features including disease onset and IUGR diagnosis. No significant correlation between different hormone levels and blood pressure measurements was reported. Conclusions: This study is the first that detected postpartum maternal serum hormone levels and their correlation with blood pressure measurements in preeclampsia. We believe that the persistent arterial hypertension in the puerperium in preeclampsia as well as poorer disease specifications are most likely not of hormonal origin. Larger, well-defined prospective studies are recommended.

Recent findings on hyperprolactinemia and its pathological implications: a literature review

The prolactin hormone (PRL) is often secreted by lactotrophic cells of the anterior pituitary and has been shown to play a role in various biological processes, including breast feeding and reproduction. The predominant form of this hormone is the 23 kDa form and acts through its receptor (PRLR) on the cell membrane. This receptor is a member of the superfamily of hematopoietic/cytokine receptors. PRL also has a 16 kDa subunit with anti-angiogenic, proapoptotic, and anti-inflammatory effects which is produced by the proteolytic breakdown of this hormone under oxidative stress. Although the common side effects of hyperprolactinemia are exerted on the reproductive system, new studies have shown that hyperprolactinemia has a wide variety of effects, including playing a role in the development of autoimmune diseases and increasing the risk of cardiovascular disease, peripartum cardiomyopathy, and diabetes among others. The range of PRL functions is increasing with the discovery of multiple sites of PRL secretion as well as PRLR expression in various tissues. This review summarizes current knowledge of the biology of PRL and its receptor, as well as the role of PRL in human pathophysiology.

New horizons in specific hormone proteolysis

Proteolysis of protein hormones is primarily acknowledged in the context of breakdown and metabolic clearance by hepatorenal elimination. However, less explored is the specific proteolytic processing of large protein hormones, for which canonical signaling pathways were already established [e.g., prolactin (PRL)], to generate unique messengers that impact cellular functions via pathways unrelated to the receptors of their precursor molecules. Yet, the proteolysis of PRL to generate new messengers evolved under positive selection, and cleaved protein hormones regulate essential functions to maintain homeostasis at the organismal, tissue, or organ levels. The cleavage sites at which proteolysis occurs and the proteases with their determinants define a hormone-metabolism junction at which specific proteolytic cleavage, pathological alteration, and hepatorenal elimination occur.

Vasoinhibin is Generated and Promotes Inflammation in Mild Antigen-induced Arthritis

Inflammatory arthritis defines a family of diseases influenced by reproductive hormones. Vasoinhibin, a fragment of the hormone prolactin (PRL), has antiangiogenic and proinflammatory properties. We recently showed that vasoinhibin reduces joint inflammation and bone loss in severe antigen-induced arthritis (AIA) by an indirect mechanism involving the inhibition of pannus vascularization. This unexpected finding led us to hypothesize that a severe level of inflammation in AIA obscured the direct proinflammatory action of vasoinhibin while allowing the indirect anti-inflammatory effect via its antiangiogenic properties. In agreement with this hypothesis, here we show that the intra-articular injection of an adeno-associated virus type-2 vector encoding vasoinhibin reduced joint inflammation in a severe AIA condition, but elevated joint inflammation in a mild AIA model. The proinflammatory effect, unmasked in mild AIA, resulted in joint swelling, enhanced leukocyte infiltration, and upregulation of expression of genes encoding proinflammatory mediators (Il1b, Il6, Inos, Mmp3), adhesion molecule (Icam1), and chemokines (Cxcl1, Cxcl2, Cxcl3, Ccl2). Furthermore, vasoinhibin induced the expression of proinflammatory mediators and chemokines in cultured synovial fibroblasts through nuclear factor-κB. Finally, matrix metalloproteases and cathepsin D, upregulated in the arthritic joint, cleaved PRL to vasoinhibin, and vasoinhibin levels increased in the circulation of mice subjected to AIA. We suggest that vasoinhibin is generated during inflammatory arthritis and acts on synovial fibroblasts and endothelial cells to initially promote and later inhibit inflammation, respectively. These opposite effects may work together to help keep joint inflammation under balance.

Human Placental Tissue Contains a Placental Lactogen Derived Vasoinhibin

Hormonal factors affecting the vascular adaptions of the uteroplacental unit in noncomplicated and complicated pregnancies are of interest. Here, 4 human placentas from women with and without preeclampsia (PE) were investigated for the presence of placental lactogen (PL)-derived, antiangiogenic vasoinhibin. Western blotting and mass spectrometry of placental tissue revealed the presence of a 9-kDa PL-derived vasoinhibin, the normal 22-kDa full-length PL, and a 28-kDa immunoreactive protein of undetermined nature. The sequence of the 9-kDa vasoinhibin includes the antiangiogenic determinant of vasoinhibin and could constitute a relevant factor in normal pregnancy and PE.

Dual Roles of Prolactin and Vasoinhibin in Inflammatory Arthritis

The term inflammatory arthritis defines a family of diseases, including rheumatoid arthritis (RA), caused by an overactive immune system, and influenced by host aspects including sex, reproductive state, and stress. Prolactin (PRL) is a sexually dimorphic, reproductive, stress-related hormone long-linked to RA under the general assumption that it aggravates the disease. However, this conclusion remains controversial since PRL has both negative and positive outcomes in RA that may depend on the hormone circulating levels, synthesis by joint tissues, and complex interactions at the inflammatory milieu. The inflamed joint is rich in matrix metalloproteases that cleave PRL to vasoinhibin, a PRL fragment with proinflammatory effects and the ability to inhibit the hyperpermeability and growth of blood vessels. This review addresses this field with the idea that explanatory mechanisms lie within the PRL/vasoinhibin axis, an integrative framework influencing not only the levels of systemic and local PRL, but also the proteolytic conversion of PRL to vasoinhibin, as vasoinhibin itself has dual actions on joint inflammation. In this review, we discuss recent findings from mouse models suggesting the upregulation of endogenous vasoinhibin by the pro-inflammatory environment and showing dichotomous actions and signaling mechanisms of PRL and vasoinhibin on joint inflammation that are cell-specific and context-dependent. We hypothesize that these opposing actions work together to balance the inflammatory response and provide new insights for understanding the pathophysiology of RA and the development of new treatments.

The interplay between prolactin and cardiovascular disease

Hyperprolactinemia can be caused by several conditions and its effects on the hypothalamic-pituitary-gonadal axis are understood in more detail. Nevertheless, in recent decades, other metabolic effects have been studied and data pointed to a potential increased cardiovascular disease (CVD) risk. A recent study showed a decrease in total and LDL- cholesterol only in men with prolactinoma treated with dopamine agonists (DA) supporting the previous results of a population study with increased CVD risk in men harboring prolactinoma. However, other population studies did not find a correlation between prolactin (PRL) levels and CVD risk or mortality. There is also data pointing to an increase in high-density lipoprotein levels, and decreases in triglycerides, carotid-intima-media thickness, C-reactive protein, and homocysteine levels in patients with prolactinoma on DA treatment. PRL was also implicated in endothelial dysfunction in pre and postmenopausal women. Withdrawal of DA resulted in negative changes in vascular parameters and an increase in plasma fibrinogen. It has been shown that PRL levels were positively correlated with blood pressure and inversely correlated with dilatation of the brachial artery and insulin sensitivity, increased homocysteine levels, and elevated D-dimer levels. Regarding possible mechanisms for the association between hyperprolactinemia and CVD risk, they include a possible direct effect of PRL, hypogonadism, and even effects of DA treatment, independently of changes in PRL levels. In conclusion, hyperprolactinemia seems to be associated with impaired endothelial function and DA treatment could improve CVD risk. More studies evaluating CVD risk in hyperprolactinemic patients are important to define a potential indication of treatment beyond hypogonadism.

A Potential Three-Gene-Based Diagnostic Signature for Hypertension in Pregnancy

Background

Hypertensive disorders of pregnancy affect approximately 5–10% of all pregnancies, and this study aims to identify potential diagnostic signatures.

Methods

We downloaded the mRNA profiles of GSE75010 (placenta samples) and GSE48424 (blood samples) datasets with or without hypertension in pregnancy from the Gene Expression Omnibus database. Differential expression analysis was performed on the placenta samples using limma package of R language. GO terms and KEGG pathways enrichment analyses were performed on the placenta samples by the clusterProfiler package of R language. Infiltrating immune cell proportion of the placenta samples was evaluated using CIBERSORT software. The key genes involved in hypertension in pregnancy were screened from protein–protein interaction (PPI) network constructed based on the differentially expressed genes (DEGs). The logistic regression model was constructed by the glm package of R language, and receiver operating characteristic (ROC) curve was plotted to determine the accuracy of the model.

Results

For the placenta samples, a total of 104 DEGs were identified, and 39 GO terms and 7 KEGG pathways were significantly enriched based on these 104 genes. Furthermore, the analysis of infiltrating immune cells indicated that the difference in the amount of immune cells might be the potential cause of hypertension in pregnancy. The logistic regression model was constructed based on three optimal genes (LEP, PRL and IGFBP1) screened from PPI network and could efficiently separate patients with hypertension in pregnancy from healthy subjects.

Conclusion

A predictive model based on three potential genes LEP, PRL and IGFBP1 was obtained, suggesting that these genes might be potential diagnostic signatures for hypertension in pregnancy.

Placental Ischemia Says "NO" to Proper NOS-Mediated Control of Vascular Tone and Blood Pressure in Preeclampsia

In this review, we first provide a brief overview of the nitric oxide synthase (NOS) isoforms and biochemistry. This is followed by describing what is known about NOS-mediated blood pressure control during normal pregnancy. Circulating nitric oxide (NO) bioavailability has been assessed by measuring its metabolites, nitrite (NO₂) and/or nitrate (NO₃), and shown to rise throughout normal pregnancy in humans and rats and decline postpartum. In contrast, placental malperfusion/ischemia leads to systemic reductions in NO bioavailability leading to maternal endothelial and vascular dysfunction with subsequent development of hypertension in PE. We end this article by describing emergent risk factors for placental malperfusion and ischemic disease and discussing strategies to target the NOS system therapeutically to increase NO bioavailability in preeclamptic patients. Throughout this discussion, we highlight the critical importance that experimental animal studies have played in our current understanding of NOS biology in normal pregnancy and their use in finding novel ways to preserve this signaling pathway to prevent the development, treat symptoms, or reduce the severity of PE.

Plasma prolactin is higher in major depressive disorder and females, and associated with anxiety, hostility, somatization, psychotic symptoms and heart rate

Background

Major Depressive Disorder (MDD) is linked to poor physical health including an increased risk of developing cardiometabolic disease (CMD), yet the underlying physiology of this relationship is not clear. One pathophysiological mechanism that may underlie this relationship is neuroendocrine dysregulation, including that of the hormone prolactin. Prolactin has a role in the regulation of stress, and it is linked to anxiety, hostility, and weight gain, which are all implicated in MDD and increased CMD risk. However, little research has examined plasma prolactin in association with psychological symptoms of MDD or biometric indices of CMD risk. Method: Plasma samples of 120 participants (n ​= ​60 meeting DSM-5 criteria for MDD and n ​= ​60 control; age and sex matched) were analysed to assess prolactin concentration. Biometric data (BMI, waist circumference, blood pressure and heart rate) were collected, and participants completed the Brief Symptom Inventory (BSI) and Depression Anxiety Stress Scale (DASS).

Results

Plasma prolactin was higher in participants with MDD versus controls (8.79 ​± ​5.16 ​ng/mL and 7.03 ​± ​4.78 ​ng/mL, respectively; F ​= ​4.528, p ​= ​0.035) and among females versus males (9.14 ​± ​5.57 ​ng/mL and 6.31 ​± ​3.70 ​ng/mL, respectively; F ​= ​9.157, p ​= ​0.003). Prolactin was correlated with several psychological symptoms including anxiety, hostility and somatization, and with heart rate, but not with any other biometric measures.

Conclusions

The results of this study indicate that neuroendocrine dysregulation in MDD may extend to the hormone prolactin, with prolactin being specifically associated with a subset of related psychometric and cardiovascular measures.

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Plasma prolactin is higher in major depressive disorder group than in controls.

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Plasma prolactin is significantly higher in females versus males.

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Prolactin is significantly correlated with heart rate.

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Prolactin is correlated with paranoid ideation, anxiety, hostility, somatization.

Relationship between Prolactin, Chronic Kidney Disease, and Cardiovascular Risk

CKD has a high prevalence worldwide, mainly due to its main etiologies-diabetes and hypertension. It has high cardiovascular morbidity and mortality, with traditional risk factors such as atherosclerosis, hypertension, diabetes, smoking, and left ventricular hypertrophy being common. Nontraditional cardiovascular risk factors, such as anemia, hyperparathyroidism, chronic inflammation, and microalbuminuria, are also well studied. Prolactin is a hormone not only related to lactation but also being considered a uremic toxin by some authors. It accumulates with loss of renal function, and it is associated with cardiovascular outcomes in both normal renal function population and CKD population. The purpose of this narrative review is to raise the main common aspects of CKD, prolactinemia, and cardiovascular risk.

Evidence for hyperprolactinemia in migraineurs: a systematic review and meta-analysis

BACKGROUND

One of the hypothalamus-pituitary axis hormones which may play a crucial role in pathophysiology of migraine is prolactin which is secreted from anterior pituitary gland and synthesized by various immune system cells as well. Whether prolactin blood levels can affect the migraine pathogenesis is an open question. Therefore, investigating prolactin circulatory levels in migraineurs may pave the way to underpin the mechanisms of migraine pathophysiology at biochemical levels. In the current investigation, the prolactin blood levels in the migraine subjects were investigated using systematic review and meta-analysis.

METHODS

Using online and specialized biomedical databases including Google Scholar, Medline, Pubmed, Pubmed Central, Embase, and Scopus, without the beginning date restriction until Feb 2019, the systematic review retrieved 11 publications in this systematic review after fulfilling for the inclusion and exclusion criteria. For heterogeneity, extent calculation statistical testing was applied. In the present study, the levels of circulatory prolactin in migraineurs assessed using standardized mean difference (SMD) as the effect size.

RESULTS

Q quantity and I²% statistic index showed a high heterogeneity in the 13 selected publications (188.370 and 92.568, respectively) and random-effects model was chosen for further analyses. The meta-analysis on a total number of 460 migraineurs and 429 healthy controls found that the weighted pooled SMD for the effects of prolactin blood concentrations on migraine pathogenesis was as follows: SMD = 1.435 (95% confidence interval, 0.854-2.015).

CONCLUSION

The current investigation presents evidence that prolactin blood levels are higher in migraineurs than healthy subjects.

Maternal and cord blood prolactin level and pregnancy complications

Objectives

To explore the correlation between maternal and cord blood prolactin, the correlation between cord prolactin and birth weight, and to compare cord blood prolactin in new-borns of women with normal pregnancy and women with pregnancy complications namely; gestational hypertension, gestational diabetes and preterm labour.

Methods

This study was performed from September to December 2018. Thirty-two women, delivered at Baghdad teaching hospital, and their newborns (32) were included. Maternal blood (5 ml) was taken before labour and cord blood (5 ml) was collected after placenta expulsion. Maternal and cord blood prolactin were analysed using fluorescence immunoassay.

Results

Cord blood prolactin was higher in babies born to hypertensive women (405.28±77.52 ng/ml) than normal pregnancy women (244.80±60.80 ng/ml), P=0.000. Also, cord prolactin in gestational hypertension group was significantly higher than diabetic (P=0.006) and preterm labour (P=0.000) groups. No significant difference was noticed in cord blood prolactin in newborns of diabetic and normal pregnancy women (299.28±37.01, 244.80±60.80 ng/ml respectively, P=0.053). Preterm babies had lower cord prolactin (204.57±22.90 ng/ml) than normal pregnancy babies (244.80±60.80 ng/ml), however the difference was non-significant, P=0.118. Positive correlation was found between cord and maternal prolactin (P=0.000) and between cord prolactin and birth weight (P=0.018).

Conclusion

Cord blood prolactin is high in newborns of hypertensive women, low in preterm neonates. Diabetes has no effect on cord prolactin level.

Ginsenoside Re inhibits PDGF-BB-induced VSMC proliferation via the eNOS/NO/cGMP pathway

Ginsenoside Re (GS-Re), which is a major monomeric member of the ginseng trialcohol saponin family, is one of the main active components of ginseng and plays an important role in protecting the cardiovascular system. Here, we report a novel function by which GS-Re regulates the eNOS/NO/cGMP pathway, which affects the platelet-derived growth factor-BB (PDGF-BB)-induced proliferation of vascular smooth muscle cells (VSMCs). GS-Re inhibited PDGF-BB-induced VSMC proliferation in a concentration-dependent manner without cytotoxicity, and the endothelial nitric oxide synthase (eNOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) antagonized the antiproliferative effect of GS-Re. The flow cytometry analysis suggested that GS-Re regulates VSMC proliferation by influencing the cell cycle transition from G0/G1 to S phase and decreasing the expression of G0/G1-specific regulatory proteins, including proliferating cell nuclear antigen (PCNA), cyclin D1, and CDK4, in PDGF-BB-treated VSMCs, consequently upregulating the protein expression of p21. After GS-Re treatment, the levels of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) and the phos-eNOS ^Ser1177/eNOS protein ratio were obviously increased. In addition, treatment with L-NAME blocked the eNOS/NO/cGMP signaling pathway, and the protein levels of PCNA, cyclin D1, and CDK4 were markedly increased in GS-Re-treated VSMCs, while p21 expression was decreased in PDGF-BB-induced VSMCs. Overall, these findings reveal that GS-Re can inhibit the proliferation of VSMCs through G0/G1 cell cycle arrest, which is closely related to eNOS/NO/cGMP pathway activation. The present results provide basic pharmacological evidence of the potential prevention and treatment of cardiovascular diseases by GS-Re.

A Dysregulation of the Prolactin/Vasoinhibin Axis Appears to Contribute to Preeclampsia

Preeclampsia is a hypertensive disorder affecting 3-5% of all pregnancies. The only curative treatment is delivery of the placenta and the pathophysiology is poorly understood. Studies have demonstrated altered levels of antiangiogenic factors in patients with preeclampsia. One such factor is the antiangiogenic and antivasodilatatory peptide hormone vasoinhibin, which is higher in the circulation, urine, and amniotic fluid of women with preeclampsia. Normal pregnancy is characterized by elevated circulating prolactin and placental lactogen levels, both of which can serve as vasoinhibin precursors when they are enzymatically cleaved. A dysregulation of vasoinhibin generation during preeclampsia is indicated by higher vasoinhibin, prolactin, placental lactogen, and vasoinhibin-generating enzymes levels and activity. The present article integrates known vasoinhibin levels, effects, and signaling mechanisms to the clinical characteristics of preeclampsia to substantiate the notion that vasoinhibin dysregulation can be causally linked to the development of preeclampsia. If this view is demonstrated, assessment of vasoinhibin levels and regulation of its activity could help estimate the risk of preeclampsia and improve its treatment.

The Effect of Modified Biolasol Solution on the Efficacy of Storing Isolated Porcine Kidneys

Biolasol is a newly developed solution for storing the liver, pancreas, kidneys, and heart by simple hypothermia. It exhibits high efficacy in maintaining structural and functional integrity of the graft prior to its transplantation. The solution was modified by the addition of ascorbic acid (0.088g/l) and ascorbic acid with prolactin (1 μg/l PRL + 0.088g/l vitamin C). The effectiveness of the obtained solutions in the protection of nephrons of isolated porcine kidneys was assessed based on the analysis of the activity of ALT (alanine aminotransferase), AST (aspartate aminotransferase), and LDH (lactate dehydrogenase) as well as lactate concentration determined in perfundates collected after 2 h (0' and 30' preservation) and 48 h (0' and 30' preservation) of graft storage. It has been found that the synergistic action of Biolasol components determines the integrity and stability of cell membranes, which in turn affects the proper functioning of the organ after transplantation. The addition of ascorbic acid and prolactin to Biolasol affects the maintenance of the normal cytoskeleton of the stored graft.

Lack of Relationships Between Serum Prolactin Concentrations and Classical Cardiovascular Risk Factors in Eastern Croatian Older Adults

Background

Relationships between serum prolactin concentrations and various CV risk factors in older adults have rarely been assessed. The aim of this study was to examine the relationships between serum prolactin concentrations and CV risk factors in older patients with multiple CV risk factors.

Material/Methods

This case-control study included 92 patients, 50–89 years old (median, 69 years), with multiple CV risk factors. We used data from general practice electronic health records and biochemical laboratory tests. Patients were divided according to categories of CV risk factors.

Results

Serum prolactin concentrations were significantly higher in elderly people (≤65 vs. >65) and in men (70.65±58.02 vs. 150.82±114.05 mIU/L), as well as in patients with lower renal function (156.70±127.23 vs. 72.53±37.25 mIU/L, the bottom vs. top quartile of creatinine clearance), higher serum homocysteine and TSH concentrations, and in those who used NSAID and statins. Parameters indicating chronic inflammation (CRP) and renal function decline (creatinine clearance) were significantly and independently correlated with increased serum prolactin concentrations in multiple regression analysis.

Conclusions

When assessing the relationships between prolactin and CV risk factors in older people with multiple CV risk factors, the effect of renal function decline and chronic inflammation should receive attention.

From Bench to Bedside: Translating the Prolactin/Vasoinhibin Axis

The prolactin/vasoinhibin axis defines an endocrine system, in which prolactin (PRL) and vasoinhibins regulate blood vessel growth and function, the secretion of other hormones, inflammatory and immune processes, coagulation, and behavior. The core element of the PRL/vasoinhibin axis is the generation of vasoinhibins, which consists in the proteolytic cleavage of their precursor molecule PRL. Vasoinhibins can interact with multiple different partners to mediate their effects in various tissues and anatomical compartments, indicating their pleiotropic nature. Based on accumulating knowledge about the PRL/vasoinhibin axis, two clinical trials were initiated, in which vasoinhibin levels are the target of therapeutic interventions. One trial investigates the effect of levosulpiride, a selective dopamine D2-receptor antagonist, on retinal alterations in patients with diabetic macular edema and retinopathy. The rationale of this trial is that the levosulpiride-induced hyperprolactinemia resulting in increased retinal vasoinhibins could lead to beneficiary outcomes in terms of a vasoinhibin-mediated antagonization of diabetes-induced retinal alterations. Another trial investigated the effect of bromocriptine, a dopamine D2-receptor agonist, for the treatment of peripartum cardiomyopathy. The rationale of treatment with bromocriptine is the inhibition of vasoinhibin generation by substrate depletion to prevent detrimental effects on the myocardial microvascularization. The trial demonstrated that bromocriptine treatment was associated with a high rate of left ventricular recovery and low morbidity and mortality. Therapeutic interventions into the PRL/vasoinhibin axis bear the risk of side effects in the areas of blood coagulation, blood pressure, and alterations of the mental state.

Human Prolactin Point Mutations and Their Projected Effect on Vasoinhibin Generation and Vasoinhibin-Related Diseases

BACKGROUND

A dysregulation of the generation of vasoinhibin hormones by proteolytic cleavage of prolactin (PRL) has been brought into context with diabetic retinopathy, retinopathy of prematurity, preeclampsia, pregnancy-induced hypertension, and peripartum cardiomyopathy. Factors governing vasoinhibin generation are incompletely characterized, and the composition of vasoinhibin isoforms in human tissues or compartments, such as the circulation, is unknown. The aim of this study was to determine the possible contribution of PRL point mutations to the generation of vasoinhibins as well as to project their role in vasoinhibin-related diseases.

METHODS

Prolactin sequences, point mutations, and substrate specificity information about the PRL cleaving enzymes cathepsin D, matrix metalloproteinases 8 and 13, and bone-morphogenetic protein 1 were retrieved from public databases. The consequences of point mutations in regard to their possible effect on vasoinhibin levels were projected on the basis of a score indicating the suitability of a particular sequence for enzymatic cleavage that result in vasoinhibin generation. The relative abundance and type of vasoinhibin isoforms were estimated by comparing the relative cleavage efficiency of vasoinhibin-generating enzymes.

RESULTS

Six point mutations leading to amino acid substitutions in vasoinhibin-generating cleavage sites were found and projected to either facilitate or inhibit vasoinhibin generation. Four mutations affecting vasoinhibin generation in cancer tissues were found. The most likely composition of the relative abundance of vasoinhibin isoforms is projected to be 15 > 17.2 > 16.8 > 17.7 > 18 kDa vasoinhibin.

CONCLUSION

Prolactin point mutations are likely to influence vasoinhibin levels by affecting the proteolysis efficiency of vasoinhibin-generating enzymes and should be monitored in patients with vasoinhibin-related diseases. Attempts to characterize vasoinhibin-related diseases should include the 15, 17.2, 16.8, 17.7, and 18 kDa vasoinhibin isoforms.