Serum Prolactin Values Research Articles

Study of hypothalamic-pituitary-testicular axis in Egyptian post-COVID-19 patients

ABSTRACT Background SARS-CoV-2, was identified as a global pandemic by the World Health Organization a few months after the first epidemic. It penetrates host cells through angiotensin-converting enzyme 2 receptors and spreads by respiratory droplets. Testes are among the several tissues that have high expression levels of ACE-2 receptors. The current study aimed to evaluate the hypothalamic-pituitary-testicular axis integrity among Egyptian post-COVID-19 patients. Methods This is a cross-sectional study that included patients with a history of COVID-19 infection, at least 3 months from the onset of COVID-19. A detailed clinical history was obtained, and a thorough examination was performed. Laboratory tests included FBG, total testosterone, free testosterone, bioactive testosterone, FSH, LH, prolactin, E2, albumin, and SHBG. Testicular ultrasonography was performed. The data were statistically analyzed. Results Eighty male patients were evaluated with a mean age of 35.53 ± 10.35 years. The mean serum total testosterone was 5.48 ± 1.65 ng/ml. Low testosterone was detected in 2.8% of the patients. High LH levels were detected in 17/80 patients (21.3%). High FSH levels were detected in 4/80 patients (5%). Six patients had elevated serum E2 level. The mean serum prolactin value was 10.90 ± 5.66 ng/ml. Fourteen patients had elevated prolactin levels. The mean serum T/LH ratio was 3.28 ± 1.52. The ratio of T/LH was decreased in eight COVID-19 patients (10%). In COVID-19 patients, a statistically significant negative correlation was found between age and free testosterone (FT) (r=-0.381, p < 0.001), bioavailable testosterone (Bio. T) (r=-0.375, p = 0.001), and androgen index (A. index) (r=-0.446, p < 0.001). Conclusion The data of the current study suggest that COVID-19 infection might deteriorate pituitary – gonadal axis. The prevalence of low testosterone in COVID-19 male survivors is low. The risk of hypogonadism is increased with advanced age. More studies are required to confirm the relationship between COVID-19 infection and male gonadal function.

Effects of long-term proton pump inhibitor use on sexual hormones and sexual and reproductive health in female patients.

Proton pump inhibitors (PPIs) are widely used to treat a range of gastrointestinal diseases around the world. Long-term use of PPIs has been associated to a variety of undesirable effects. Although short-term therapy has been shown to have little or no effect on endocrine hormone in women, however, its long-term safety has received little attention. We aimed at evaluating long-term use of PPIs and its effects on female reproductive hormones as well as related clinical consequences. A cross-sectional study was conducted in two outpatient gastroenterology clinics in the province of Khyber Pakhtunkhwa. This study included female patients who had been using PPIs on a regular basis for 3 months or more. In total of 101 participants, patients with sexual complaints have significantly altered levels of prolactin (p = 0.05), estrogen (p < 0.001) and progesterone (p = 0.001) than patient without sexual complaints. The frequency of amenorrhea (p < 0.001), cyclic disturbances (p < 0.001), breast augmentation (p = 0.001) and painful breast (p = 0.004) were statistically significant in patients with raised serum prolactin values. Serum values of Sex hormone binding globulin SHBG (p < 0.001), estradiol (p = 0.002) and total testosterone (p < 0.001) were significantly altered between normal prolactin and hyperprolactinemic patients. These findings suggest that long-term PPI use may cause endocrine hormone disturbances leading to sexual difficulties in women.

FRI298 Serum Prolactin To Tumor Size Ratio As An Effective Parameter To Accurately Distinguish Prolactinoma From NFPT

Abstract Disclosure: I. Mishra: None. A. Pradhan: None. A.K. Baliarsinha: None. Preoperative diagnosis of prolactinomas is critical because dopamine agonists therapy have been regarded as a primary treatment. Multiple studies have compared serum prolactin levels in clinically nonfunctioning (NF) tumors and prolactinomas to identify cutoffs that may distinguish primary tumoral secretion from stalk effect. Prolactin levels are correlated with the size of prolactinomas but are not associated with tumor size in non prolactin-secreting lesions or the degree of stalk deviation and compression. By using the tumor size, we investigated an effective parameter for the discrimination between prolactinoma and NFPT. 33 patients with pituitary lesion of histological diagnosis were retrospectively recruited for this study. The data obtained was entered into Microsoft Excel Worksheet and analysed using Statistical Package for Social Sciences (SPSS, IBM Corp. Released 2020. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp.).The Prolactinoma group (n=16) showed higher serum prolactin (mean=418 ng/mL) than those in the NFPT group (n=17) (mean=33.34 ng/mL, p-values &amp;lt; 0.001).Using receiver operating curve analyses, we compared diagnostic performances of serum prolactin (PRL)/ tumor volume ratio in both groups. Unlike NFPT, serum prolactin values significantly correlated with tumor volume in Prolactinoma group. At a cut off of 12.2ng/ml/cm3,serum PRL/tumor volume was found to have a sensitivity of75.8% in diagnosing prolactinomas. However the specificity was 24.2%. Burke et al and Wright et al studied significantly smaller groups of patients and reported a linear relationship between prolactin levels and prolactinoma volume as estimated by a simplified ellipsoid volume equation. Our study demonstrates that the assessment of prolactin secretory density, based on a calculation of serum prolactin per unit tumor volume, can be used as a potential method to distinguish prolactinomas from hyperprolactinemia secondary to stalk effect and could be valuable in guiding patient management in equivocal or challenging patient cases wherein the etiology of hyperprolactinemia is uncertain. Reference: (1) Burke WT, Penn DL, Castlen JP, et al. Prolactinomas and nonfunctioning adenomas: preoperative diagnosis of tumor type using serum prolactin and tumor size. J Neurosurg. 2019:1e8.(2) Wright K, Lee M, Escobar N, et al. Tumor volume improves preoperative differentiation of prolactinomas and nonfunctioning pituitary adenomas.Endocrine.2021;74(1):138e145 Presentation: Friday, June 16, 2023

Association of prolactin with all-cause and cardiovascular mortality among patients with type 2 diabetes: a real-world study.

The association between prolactin and mortality has been less studied, and findings were inconsistent among different populations. We aimed to investigate the association between serum prolactin (PRL) and mortality among patients with type 2 diabetes. We performed a retrospective cohort study of 10 907 patients with at least 2 prolactin measurements within 2 years since their first inpatient diagnosis of type 2 diabetes. Baseline and mean values of serum PRL were used as exposures. A multivariable-adjusted Cox proportional hazards model was used to estimate the association between PRL and mortality. During a mean follow-up of 5.34 years, 863 patients died, of whom 274 were due to cardiovascular events. Multivariable-adjusted hazard ratios (aHRs) based on different levels of baseline PRL (<100, 100-199, 200-299, and ≥300 mIU/L) were 1.00, 1.10 [95% confidence interval (CI), 0.90-1.36], 1.35 (95% CI 1.11-1.67), and 1.49 (95% CI 1.18-1.84) for all-cause mortality and 1.00, 1.24 (95% CI 0.86-1.81), 1.71 (95% CI 1.14-2.62), and 2.42 (95% CI 1.55-3.78) for cardiovascular mortality, respectively. Positive associations were also found when we used the mean values of PRL as the exposure. These associations were consistent among patients of different baseline characteristics. Further sensitivity analyses excluding patients with subclinical or clinical hypothyroidism at baseline and who died within the first 6 months since baseline demonstrated similar results. A positive association between baseline PRL and mortality was observed among patients with type 2 diabetes. Prolactin may be considered a potential biomarker of mortality among patients with type 2 diabetes.

A Comparative Study of Intravenous Dexmedetomidine with Local Infiltration of Ropivacaine in Attenuation of Stress Response to Skull Pin Insertion in Craniotomies.

Objective Skull pin insertion in patients undergoing craniotomies elicits hemodynamic and neuroendocrine stress response that may be deleterious to the patient. Various drugs and techniques have been documented in literature to abate this stress response. Against this background, we aimed to compare the efficacy of intravenous dexmedetomidine and local infiltration of ropivacaine for attenuation of stress response to pin insertion in craniotomies. Methods Eighty-eight adult patients undergoing craniotomy under general anesthesia from March 2019 to April 2020 requiring application of head holder were randomized into two equal groups. After intubation, 0.75 µg kg -1 of dexmedetomidine over 10 minutes through infusion was given in group D, while local infiltration at pin sites was done with 0.5% ropivacaine, 2 mL at each site in group R. Hemodynamic parameters and levels of serum cortisol, prolactin, and blood glucose were measured before and after pin insertion. Unpaired t -test for continuous variables and Mann-Whitney U test was used for nonnormally distributed variables. Results Heart rate was statistically similar between the two groups at all the observed time points. The difference in mean arterial pressure values between the two groups was found to be statistically significant only from 10 to 20 minutes after pin insertion being statistically similar at rest of the time points. Levels of serum glucose, cortisol, and prolactin values 30 minutes after pin insertion were statistically similar between both groups. Conclusion We concluded that both interventions are equally efficacious in attenuation of hemodynamic and stress response to head holder application in patients undergoing craniotomies.

Serum Neurofilament Levels in Children With Febrile Seizures and in Controls

ObjectiveNeuroaxonal damage is reflected by serum neurofilament light chain (sNfL) values in a variety of acute and degenerative diseases of the brain. The aim of this study was to investigate the impact of febrile and epileptic seizures on sNfL, serum copeptin, and prolactin levels in children compared with children with febrile infections without convulsions.MethodsA prospective cross-sectional study was performed in children aging 6 months to 5 years presenting with fever (controls, n = 61), febrile seizures (FS, n = 78), or epileptic seizures (ES, n = 16) at our emergency department. sNfL, copeptin, and prolactin were measured within a few hours after the event in addition to standard clinical, neurophysiological, and laboratory assessment. All children were followed up for at least 1 year after presentation concerning recurrent seizures.ResultsSerum copeptin values were on average 4.1-fold higher in FS and 3.2-fold higher in ES compared with controls (both p < 0.01). Serum prolactin values were on average 1.3-fold higher in FS compared with controls ( p < 0.01) and without difference between ES and controls. There was no significant difference of mean sNfL values (95% CI) between all three groups, FS 21.7 pg/ml (19.6–23.9), ES 17.7 pg/ml (13.8–21.6), and controls 23.4 pg/ml (19.2–27.4). In multivariable analysis, age was the most important predictor of sNfL, followed by sex and C reactive protein. Neither the duration of seizures nor the time elapsed from seizure onset to blood sampling had an impact on sNfL. None of the three biomarkers were related to recurrent seizures.SignificanceSerum neurofilament light is not elevated during short recovery time after FS when compared with children presenting febrile infections without seizures. We demonstrate an age-dependent decrease of sNfL from early childhood until school age. In contrast to sNfL levels, copeptin and prolactin serum levels are elevated after FS.

Low prolactin levels are associated with visceral adipocyte hypertrophy and insulin resistance in humans.

Low prolactin (PRL) serum levels are associated with glucose intolerance and type 2 diabetes in adults, and with metabolic syndrome and obesity in children. In obese rodents, PRL treatment promotes insulin sensitivity by maintaining adipose tissue fitness, and lack of PRL signaling exacerbates obesity-derived metabolic alterations. Since adipose tissue dysfunction is a key factor triggering metabolic alterations, we evaluated whether PRL serum levels are associated with adipocyte hypertrophy (a marker of adipose tissue dysfunction), insulin resistance, and metabolic syndrome in lean, overweight, and obese adult men and women. Samples of serum and adipose tissue from 40 subjects were obtained to evaluate insulin resistance index (homeostasis model assessment of insulin resistance (HOMA-IR)), signs of metabolic syndrome (glucose levels, high-density lipoproteins, triglycerides, blood pressure, and waist circumference), as well as adipocyte size and gene expression in fat. Lower PRL serum levels are associated with adipocyte hypertrophy, in visceral but not in subcutaneous fat, and with a higher HOMA-IR. Furthermore, low systemic PRL levels together with high waist circumference predict an elevated HOMA-IR whereas low serum PRL values in combination with high blood glucose predicts visceral adipocyte hypertrophy. In agreement, visceral fat from insulin resistant subjects shows reduced expression of prolactin receptor. However, there is no association between PRL levels and obesity or signs of metabolic syndrome. Our results support that low levels of PRL are markers of visceral fat dysfunction and insulin resistance, and suggest the potential therapeutic value of medications elevating PRL levels to help maintain metabolic homeostasis.

Investigating the Role of Prolactin as a Potential Biomarker of Stress in Castrated Male Domestic Dogs.

Simple SummaryAlthough cortisol is usually considered the main reference for the assessment of stress, in some animal species it has been shown that prolactin can be used as a biomarker of both acute and chronic stress. Behavioural parameters can also be used to assess the state of welfare and stress. This study was aimed at evaluating the possible relationship between serum prolactin, serum cortisol and behavioural signs of stress in domestic dogs. To reduce the possible influence of some factors, the study was performed on a homogeneous sample formed by 40 castrated male Spanish Greyhound dogs housed in a dog shelter. The weak negative correlation found between serum cortisol and prolactin values agrees with results obtained in other studies, indicating that prolactin response might be an alternative to cortisol response.Prolactin has been recently regarded as a potential biomarker of both acute and chronic stress in several species. Since only few studies until now have focussed on domestic dogs, this study was aimed at evaluating whether prolactin, cortisol and stress behaviour correlated with each other in sheltered dogs. Both cortisol and prolactin analysis were performed in serum samples through a hormone-specific ELISA kit. For each dog, a stress score was calculated by summing the number of occurrences of stress-related behaviours. The presence/absence of fear during the time spent in the collection room was also scored for each individual. Results revealed a weak negative correlation between cortisol and prolactin levels. Neither of the hormones was correlated with the stress score, nor did their values seem to be influenced by showing fear in the collection room. The weak negative correlation found between cortisol and prolactin values agrees with results obtained in other studies, indicating that prolactin response might be an alternative to cortisol response. This, together with the high serum prolactin levels compared to those reported by other authors for healthy domestic dogs, may indicate that prolactin might be a good biomarker of chronic stress, and although further studies are needed to better understand the potential role of prolactin in the evaluation of canine welfare.

Alternative methods for the diagnosis of macroprolactinemia: urine prolactin level and serum / urine prolactin ratio

Objective: The aim of this study was to investigate the urine prolactin and serum/urine prolactin ratio for accuracy diagnosis of macroprolactinemia. Methods: In the retrospective cross-sectional analysis, prolactin levels (high or normal) in the reproductive period of men and women were included in the study. Polyethylene glycol (PEG) precipitation method was used for the detection of macroprolactinemia. Then, patients were divided into three groups as macroprolactinemia, prolactinoma and healthy control group. In patients, prolactin values in spot urine with simultaneous serum prolactin values were calculated. The non-parametric Kruskal-Wallis test was used to compare the groups. The receiver-operating characteristic (ROC) curve was determined to evaluate the predictive power of serum/urine prolactin ratio. Results: A total of 41 patients were included in the study. Female/male:36 (87.8%)/ 5 (12.2%). Urinary prolactin median(minimum-maximum) values were macroprolactinemia, prolactinoma and control group, respectively; 0.06(0.05-0.10), 0.11(0.02-0.95), 0.08(0.05-0.25) ng/ml. Serum/urine ratio median (minium-maximum) values were macroprolactinemia, prolactinoma, and control group, respectively; 633(51-1032), 990(104-9635), 395.5(138-953). When the groups were compared, the patients with prolactinoma had higher urinary prolactin levels(p 549,5 AUC=0.83) p<0.01 Conclusion: Urinary prolactin level and serum/urine prolactin ratio may be used in diagnosis of macroprolactinemia.

Add-on Aripiprazole for Atypical Antipsychotic-induced, Clinically Significant Hyperprolactinemia.

Background:Antipsychotic treatment-induced hyperprolactinemia is a highly distressing and disabling side effect for patients. The use of add-on aripiprazole has been identified as a possible treatment strategy in this situation. However, data on prolactin changes with add-on aripiprazole in a real-world naturalistic clinical setting from India are sparse.Materials and Methods:The retrospective chart review was conducted at the specialty metabolic clinic at the National Institute of Mental Health and Neurosciences, Bengaluru, India. Sixteen patients (female: male = 13:3) who were on a stable dose of antipsychotic medications, complaining of either sexual dysfunction or menstrual irregularities, were prescribed add-on aripiprazole. The serum prolactin values were obtained before the initiation of aripiprazole and during the follow-up.Results:Patients were on treatment with risperidone, amisulpride, and olanzapine and had a prolactin level of 87.1 ± 60.7 ng/ml. Add-on aripiprazole treatment was given with a mean dose of 13.8 ± 7.4 mg/day. Patients had a significant reduction in prolactin level (35.6 ± 29.1 ng/ml) following treatment with aripiprazole (P = 0.004).Conclusions:Add-on aripiprazole could be a clinically useful strategy in patients who develop antipsychotic-induced hyperprolactinemia.

Relationship between Semen Volume and blood Hormone in Azoospermic Males

Aim: To investigate the relationship between semen volume and serum follicle — stimulating hormone (FSH), Luteinizing hormone (LH), testosterone (T), and prolactin (PRL) in azoospermic infertile patients. Methods: Serum FSH, LH, testosterone and prolactin levels of 25 male infertile azoospermic patients were assayed by radioimmunoassay (RIA) and their data was analyzed for significant correlation with the same parameters of 25 control cases. Results: 25 infertile patients had azoospermic. The values of serum FSH, LH, and prolactin were significantly raised (P < 0.05) while the serum testosterone significantly lower (P < 0.05). The semen volume in the azoospermic patients was negative strongly correlated to serum FSH, LH and serum prolactin. FSH (r = 0.93), LH (r = 0.95) prolactin (r = 93). The semen volume was positive strongly correlated to serum testosterone (r = 0.90). Conclusion: high levels of serum FSH, LH, prolactin and low levels of serum testosterone can cause infertility by azoospermic directly.

Prolactin Promotes Adipose Tissue Fitness and Insulin Sensitivity in Obese Males.

Excessive accumulation of body fat triggers insulin resistance and features of the metabolic syndrome. Recently, evidence has accumulated that obesity, type 2 diabetes, and metabolic syndrome are associated with reduced levels of serum prolactin (PRL) in humans and rodents, raising the question of whether low PRL levels contribute to metabolic dysfunction. Here, we have addressed this question by investigating the role of PRL in insulin sensitivity and adipose tissue fitness in obese rodents and humans. In diet-induced obese rats, treatment with PRL delivered via osmotic mini-pumps, improved insulin sensitivity, prevented adipocyte hypertrophy, and reduced inflammatory cytokine expression in visceral fat. PRL also induced increased expression of Pparg and Xbp1s in visceral adipose tissue and elevated circulating adiponectin levels. Conversely, PRL receptor null mice challenged with a high-fat diet developed greater insulin resistance, glucose intolerance, and increased adipocyte hypertrophy compared with wild-type mice. In humans, serum PRL values correlated positively with systemic adiponectin levels and were reduced in insulin-resistant patients. Furthermore, PRL circulating levels and PRL produced by adipose tissue correlated directly with the expression of PPARG, ADIPOQ, and GLUT4 in human visceral and sc adipose tissue. Thus, PRL, acting through its cognate receptors, promotes healthy adipose tissue function and systemic insulin sensitivity. Increasing the levels of PRL in the circulation may have therapeutic potential against obesity-induced metabolic diseases.

Prolactin levels in drug-naïve patients with schizophrenia and other psychotic disorders

Objective: Hyperprolactinaemia as a side effect of dopamine receptor blockers is common in patients with schizophrenia and other psychotic disorders and may lead to amenorrhoea, galactorrhoea, hypogonadism, subfertility and osteoporosis. The aim of our study was to determine whether hyperprolactinaemia occurs also in patients with schizophrenia and other psychotic disorders prior to any antipsychotic treatment.Methods: Serum prolactin, thyroid-stimulating hormone (TSH), triiodothyronine (T3), free tetraiodothyronine (FT4) and cortisol levels were measured in 40 newly diagnosed, drug naïve, patients with schizophrenia and other psychotic disorders and in 40 age and gender matched healthy subjects.Results: The median prolactin value was 12.5 ng/ml (range: 2–38 ng/ml) for patients and 8.6 ng/ml (range: 4–17.6 ng/ml) for healthy subjects (p = 0.011). Patients had lower levels of T3 compared to healthy controls (mean: 1.08 ng/ml, SD: 0.16 vs. 1.18 ng/ml, 0.18, respectively; p = 0.008). Serum TSH, FT4 and cortisol levels were similar between the two groups. Multiple regression analysis revealed that the difference in serum prolactin values was independent of thyroid function (TSH, FT4, T3) and serum cortisol levels.Conclusions: A higher serum prolactin level was found in drug naïve, newly diagnosed patients with schizophrenia and other psychotic disorders compared to healthy controls, prior to starting any antipsychotic treatment.

Ultrasound-guided percutaneous microwave ablation for adenomyosis: efficacy of treatment and effect on ovarian function.

A total of 142 premenopausal women with symptomatic adenomyosis underwent ultrasound (US)-guided percutaneous microwave ablation (PMWA) at the Chinese PLA General Hospital. This study aimed to evaluate changes in serum pituitary, gonadal hormone and cancer antigen 125 (CA125) levels after US-guided PMWA. Therefore, estradiol (E2), follicle-stimulating hormone (FSH), prolactin (PRL) and CA125 levels were evaluated before ablation and at 3, 6, 9 and 12 months after ablation. No significant differences were observed in the E2 and FSH levels pre-ablation and during follow-up (E2: p = 0.933, p = 0.987, p = 0.106, p = 0.936; FSH: p = 0.552, p = 0.295, p = 0.414, p = 0.760). The mean absolute values of serum CA125 and PRL were significantly decreased at 3, 6, 9 and 12 months after ablation (CA125: p < 0.001, p < 0.001, p < 0.001, p = 0.003; PRL: p < 0.001, p < 0.001, p < 0.001, p < 0.001). A significant correlation between changes in CA125 levels and uterine volume was found (p < 0.001). No evidence of a decline in ovarian function was observed after US-guided PMWA.

Breast carcinomas with hyperprolactinemia at the time of diagnosis-clinico-biological association

Aim: To analyse association between preoperative hyperprolactinemia serum levels and clinical and biological features of breast tumors. Methods: Serum levels of prolactin were measured in 253 women with invasive breast cancer. Clinical and biological parameters analysed were age, size, lymph node involvement, distant metastasis and immunohistochemical expression of estrogen receptor, progesterone receptor, androgen receptor, bcl-2, p53 and Ki67. Results: In ductal carcinomas hyperprolactinemia were associated with high age (p = 0.017), and with bcl-2 + + + expression (p = 0.017). Furthermore, serum prolactin values were significantly higher in bcl-2 +++ cases vs negative (p = 0.029); the same happened when we considered the positivity threshold of 25 ng/mL (p = 0.015). Conclusion: Is possible to detect in 6% of infiltrating ductal breast carcinomas hyperprolactinemia (>25 ng/mL), being associated only with increasing age, but not with other clinical or biological factors; and 2) the most surprising data was the association between prolactinemia (qualitative (>25 ng/mL) and quantitative) and intense bcl-2 tissue expression, which suggests that, probably, this (prolactinemia) is not a sign of worse prognosis and evolution.

Ectopic prolactinoma within the sphenoidal sinus associated with empty sella

Background:Pituitary adenomas are a common cause of endocrinal dysfunction, which comprise 10–20% of all intracranial tumors. Although almost all of them arise within the sella turcica, there are some rare cases in which a pituitary adenoma is located outside the intrasellar region, so it is defined as an ectopic pituitary adenoma (EPA).Case Description:We described a case of a 31-year-old male with a serum prolactin (PRL) value of 240 ng/ml Magnetic resonance imaging (MRI) showed a space-occupying mass within the sphenoid sinus (SS) which partially enhanced by gadolinium. MRI did not reveal any sellar floor defect and an empty sella was detected. As dopamine agonist treatment had failed in lowering the serum PRL level, he underwent surgical treatment. A transsphenoidal approach without opening the sellar floor was performed using an operating microscope and the lesion within the SS was completely removed.Conclusion:Although intrasphenoidal EPAs are rare findings, the presence of an endocrine disorder related to pituitary hormones, and a space-occupying mass within the SS associated with either a normal sellar pituitary gland or an empty sella must lead us to suspect this diagnosis.

Regulation of prolactin secretion during the estrus in rats: possible role of glucocorticoids

Mifepristone (MIF) administration to cycling rats at proestrus induces hypersecretion of prolactin (PRL) at the following estrus. We aimed to assess whether this effect is due to the antiprogesterone or antiglucocorticoid action of MIF and to help underscore the nature of the circulating hormone(s) regulating PRL secretion at estrus. Female cycling rats in proestrus were treated with vehicle; the progesterone (Pg) and glucocorticoid receptor antagonists, MIF (5 mg/kg) or ORG-33628 (5 mg/kg); the glucocorticoid agonist dexamethasone (DEX; 27 mg/kg)±MIF; or the inhibitor of steroid synthesis aminoglutethimide (AG; 150 mg/kg)±MIF. The animals' blood was sampled the same day at 1800 h and at 1800 h of the following day to assess for circulating PRL and Pg levels. To distinguish antiglucocorticoid from antiprogesterone effects of MIF, we administered a highly specific neutralizing antibody against Pg. None of the antagonists modified serum PRL values at proestrus but increased PRL levels at estrus. DEX decreased the secretion of PRL at proestrus, yet the effect was entirely blocked by MIF. Furthermore, DEX decreased PRL at estrus in a MIF-reversible manner, suggesting that adrenal corticoids during proestrous may regulate PRL secretion at estrus. AG increased PRL secretion at estrus, whereas its association with MIF produced an even higher response. PRL concentration at estrus was not modified by the antiprogesterone antibody, suggesting that the effect of MIF is a consequence of its antiglucocorticoid effect and not due to its antiprogesterone properties. In conclusion, PRL secretion in the afternoon of the estrus is most likely regulated by glucocorticoids through an inhibitory action.

High prevalence of radiological vertebral fractures in women with prolactin-secreting pituitary adenomas

Hyperprolactinemia may cause bone loss but data on fractures are scanty. The aim of this study was to evaluate the prevalence of vertebral fractures in women with prolactin (PRL)-secreting adenoma. In this cross-sectional study, 78 women (median age 45.5 years, range: 20-81) with PRL-secreting pituitary adenoma (66 with microadenoma and 12 with macroadenoma) and 156 control subjects, with normal PRL values and with comparable age to patients with hyperprolactinemia, were evaluated for vertebral fractures by a morphometric approach and for bone mineral density (BMD) by a dual-energy X-ray absorptiometry at lumbar spine. Vertebral fractures were shown in 25 patients with PRL-secreting adenoma (32.6%) and in 20 controls (12.8%, P < 0.001). Fractured patients were significantly older (P < 0.001) and had lower BMD T-score (P < 0.001), longer duration of disease (P < 0.001), higher serum PRL (P = 0.004) and lower serum IGF-I (P < 0.001) values as compared to patients who did not fracture. The prevalence of vertebral fractures was significantly (P < 0.001) higher in post-menopausal women with PRL-secreting adenoma as compared to pre-menopausal patients. Fractures occurred more frequently (P = 0.01) in patients with untreated hyperprolactinemia versus patients treated with cabergoline. Logistic regression analysis demonstrated that duration of disease maintained a significant correlation with vertebral fractures (odds ratio 1.16, C.I. 95% 1.02-1.33) even after correction for age, menopausal status, treatment with cabergoline, BMD, serum IGF-I and serum PRL values. Hyperprolactinemia is associated with high prevalence of radiological vertebral fractures in women with PRL-secreting adenoma.

Use of prolactin as an indicator of stress in Marwari sheep from arid tracts in India

Serum prolactin (PRL) and cortisol levels were determined in sheep of the Marwari breed from arid tracts in Rajasthan state, India to assess the role of serum PRL as an indicator of stress. Serum levels of PRL and cortisol were determined by radioimmunoassay in healthy and affected sheep (haemonchus infected, pneumonia affected, having enterotoxaemia and drought affected). The affected group showed significantly (p ≤ 0.05) higher levels of serum PRL and cortisol when compared to the healthy group. The mean rise in PRL was 4.72 times, whereas cortisol levels were 4.28 times higher. In the affected group, a significant (p ≤ 0.05) correlation was observed between the values of serum PRL and cortisol. A multiple fold rise in serum PRL clearly suggested that it can be used as an indicator of stress in different pathologies in sheep.

A case of paroxetine-induced galactorrhoea with normal serum prolactin level

The following case report highlights an interesting observation of paroxetine-induced galactorrhoea at therapeutic dosage and serum prolactin values of this patient comes out to be normal. This observation merits a systematic study to find the causal relationship of this unusual phenomenon and further explanation.