Intranasal delivery of sulpiride nanostructured lipid carrier to central nervous system; in vitro characterization and in vivo study.

The low and erratic oral absorption of sulpiride (SUL) a dopaminergic receptor antagonist, and its P-glycoprotein efflux in the gastrointestinal tract restricted its oral route for central nervous system disorders. An intranasal formulation was formulated based on nanostructured lipid carrier to tackle these obstacles and deliver SUL directly to the brain. Sulipride-loaded nanostructured lipid carrier (SUL-NLC) was prepared using compritol®888 ATO and different types of liquid lipids and emulsifiers. SUL-NLCs were characterized for their particle size, charge, and encapsulation efficiency. Morphology and compatibility with other NLC excipients were also studied. Moreover, SUL in vitro release, nanodispersion stability, in vivo performance and SUL pharmacokinetics were investigated. Results delineates that SUL-NLC have a particle size ranging from 366.2 ± 62.1 to 640.4 ± 50.2 nm and encapsulation efficiency of 75.5 ± 1.5%. SUL showed a sustained release pattern over 24 h and maintained its physical stability for three months. Intranasal SUL-NLC showed a significantly (p < 0.01) higher SUL brain concentration than that found in plasma after oral administration of commercial SUL product with 4.47-fold increase in the relative bioavailability. SUL-NLCs as a nose to brain approach is a promising formulation for enhancing the SUL bioavailability and efficient management of neurological disorders.

Phosphoproteomic Analysis of Dopamine D2 Receptor Signaling Reveals Interplay of G Protein- and ß-Arrestin-Mediated Effects.

Leveraging biased signaling of G protein-coupled receptors has been proposed as a promising strategy for the development of drugs with higher specificity. However, the consequences of selectively targeting G protein- or ß-arrestin-mediated signaling on cellular functions are not comprehensively understood. In this study, we utilized phosphoproteomics to gain a systematic overview of signaling induced by the four biased and balanced dopamine D2 receptor (D2R) ligands MS308, BM138, quinpirole, and sulpiride in an in vitro D2R transfection model. Quantification of 14,160 phosphosites revealed a low impact of the partial G protein agonist MS308 on cellular protein phosphorylation, as well as surprising similarities between the balanced agonist quinpirole and the inverse agonist sulpiride. Analysis of the temporal profiles of ligand-induced phosphorylation events showed a transient impact of the G protein-selective agonist MS308, whereas the ß-arrestin-preferring agonist BM138 elicited a delayed, but more pronounced response. Functional enrichment analysis of ligand-impacted phosphoproteins and treatment-linked kinases confirmed multiple known functions of D2R signaling while also revealing novel effects, for example of MS308 on sterol regulatory element-binding protein-related gene expression. All raw data were deposited in MassIVE (MSV000089457).

Alpha-2 Adrenoreceptor Antagonist Yohimbine Potentiates Consolidation of Conditioned Fear.

BACKGROUND: Hyperconsolidation of aversive associations and poor extinction learning have been hypothesized to be crucial in the acquisition of pathological fear. Previous animal and human research points to the potential role of the catecholaminergic system, particularly noradrenaline and dopamine, in acquiring emotional memories. Here, we investigated in a between-participants design with 3 groups whether the noradrenergic alpha-2 adrenoreceptor antagonist yohimbine and the dopaminergic D2-receptor antagonist sulpiride modulate long-term fear conditioning and extinction in humans. METHODS: Fifty-five healthy male students were recruited. The final sample consisted of n = 51 participants who were explicitly aware of the contingencies between conditioned stimuli (CS) and unconditioned stimuli after fear acquisition. The participants were then randomly assigned to 1 of the 3 groups and received either yohimbine (10 mg, n = 17), sulpiride (200 mg, n = 16), or placebo (n = 18) between fear acquisition and extinction. Recall of conditioned (non-extinguished CS+ vs CS-) and extinguished fear (extinguished CS+ vs CS-) was assessed 1 day later, and a 64-channel electroencephalogram was recorded. RESULTS: The yohimbine group showed increased salivary alpha-amylase activity, confirming a successful manipulation of central noradrenergic release. Elevated fear-conditioned bradycardia and larger differential amplitudes of the N170 and late positive potential components in the event-related brain potential indicated that yohimbine treatment (compared with a placebo and sulpiride) enhanced fear recall during day 2. CONCLUSIONS: These results suggest that yohimbine potentiates cardiac and central electrophysiological signatures of fear memory consolidation. They thereby elucidate the key role of noradrenaline in strengthening the consolidation of conditioned fear associations, which may be a key mechanism in the etiology of fear-related disorders.

Effect of sulpiride on menopausal hot flashes: a randomized, double-blind, placebo-controlled clinical trial.

Low doses of sulpiride have been used off-label to treat menopausal hot slashes in Southern Brazil despite limited scientific evidence. This randomized controlled trial aimed at assessing the effects of sulpiride as compared to placebo on the frequency and severity of hot flashes. Postmenopausal women, aged 47-62, were recruited from the Menopause Clinic at Hospital de Clínicas de Porto Alegre, Rio Grande do Sul, Brazil, between March 2016 and January 2017. After a baseline assessment of 4 weeks, women were included if they had at least a mean of five moderate to severe hot flashes per day and then randomized to receive for 8 weeks either placebo (n= 14) or sulpiride 50 mg/d (n= 14). The number and severity of hot flashes were evaluated after the 8-week intervention. A generalized estimating equations (GEE) model with Bonferroni correction was used to simultaneously assess the frequency and severity of hot flashes. Baseline frequency and severity of hot flashes/day were similar in both groups. Sulpiride significantly reduced the total weekly mean of hot flash frequency (GEE, pinteraction=.019) and the total weekly mean of severity scores (GEE, pinteraction=.09, pgroup=.006, ptime≤.0001) after 4 and 8 weeks of treatment. Treatment with sulpiride 50 mg/d significantly reduced the frequency and severity of hot flashes. Further studies are needed to confirm its benefits and related mechanisms of action.

Expanding Role of Dopaminergic Inhibition in Hypercapnic Responses of Cultured Rat Carotid Body Cells: Involvement of Type II Glial Cells.

Dopamine (DA) is a well-studied neurochemical in the mammalian carotid body (CB), a chemosensory organ involved in O2 and CO2/H+ homeostasis. DA released from receptor (type I) cells during chemostimulation is predominantly inhibitory, acting via pre- and post-synaptic dopamine D2 receptors (D2R) on type I cells and afferent (petrosal) terminals respectively. By contrast, co-released ATP is excitatory at postsynaptic P2X2/3R, though paracrine P2Y2R activation of neighboring glial-like type II cells may boost further ATP release. Here, we tested the hypothesis that DA may also inhibit type II cell function. When applied alone, DA (10 µM) had negligible effects on basal [Ca2+]i in isolated rat type II cells. However, DA strongly inhibited [Ca2+]i elevations (Δ[Ca2+]i) evoked by the P2Y2R agonist UTP (100 µM), an effect opposed by the D2/3R antagonist, sulpiride (1-10 µM). As expected, acute hypercapnia (10% CO2; pH 7.4), or high K+ (30 mM) caused Δ[Ca2+]i in type I cells. However, these stimuli sometimes triggered a secondary, delayed Δ[Ca2+]i in nearby type II cells, attributable to crosstalk involving ATP-P2Y2R interactions. Interestingly sulpiride, or DA store-depletion using reserpine, potentiated both the frequency and magnitude of the secondary Δ[Ca2+]i in type II cells. In functional CB-petrosal neuron cocultures, sulpiride potentiated hypercapnia-induced Δ[Ca2+]i in type I cells, type II cells, and petrosal neurons. Moreover, stimulation of type II cells with UTP could directly evoke Δ[Ca2+]i in nearby petrosal neurons. Thus, dopaminergic inhibition of purinergic signalling in type II cells may help control the integrated sensory output of the CB during hypercapnia.

Prostatotropic Action of Glycyrrhizic Acid Disodium Salt in Benign Prostatic Hyperplasia Models.

The prostatotropic activity of glycyrrhizic acid disodium salt (Na2GA) was studied in the models of benign prostatic hyperplasia (BPH) induced by chronic injection of sulpiride (40 mg/kg intraperitoneally for 8 weeks) or testosterone propionate (20 mg/kg subcutaneously for 4 weeks) in the Wistar rats. The oral administration of Na2GA in a dose of 100 mg/kg produced a moderate antiproliferative effect in both BPH models resulting in reduced volume density of prostatic epithelium (in the testosterone model) and increased volume density of the glandular lumen (in both models). The observed prostatotropic effects of Na2GA were similar to those of Permixon and finasteride, but they were less pronounced as confirmed by smaller drops in epithelial volume density and epithelial-to-stromal ratio compared to the effects of both reference drugs.

Preclinical PK/PD model for the combinatorial use of dexamethasone and sulpiride in the treatment of breast cancer.

Previous studies show that dopamine D2-like receptor (D2DR) antagonist sulpiride (SUL) enhances the antitumor efficacy of dexamethasone (DEX) in drug-resistant breast cancer involving cancer stem-like cells (CSCs). In this study, we investigated the pharmacokinetic (PK) properties of SUL in nude mice and developed a semi-mechanism PK/PD model to quantitatively characterize the synergistic effect of DEX and SUL in preclinical breast cancer xenografts. After nude mice received oral administration of a single dose of SUL (50 mg/kg, ig), plasma concentrations were assessed using LC-MS/MS. A two-compartment model with double first-order absorption rate was developed to describe the PK profiles of SUL. The pharmacodynamic (PD) study was conducted in nude mice bearing human breast cancer MCF-7/Adr xenografts, which received oral administration of DEX (1, 8 mg·kg-1·d-1) or SUL (25, 50 mg·kg-1·d-1) alone or in various combination. Tumor volumes were measured every other day. The PK model of SUL as well as that of DEX with a time-dependent clearance were integrated into the final PK/PD model both using Hill's function, where DEX exerted its antitumor efficacy by inhibiting the proliferation of tumor cells, and SUL enhanced DEX responses by decreasing the sensitivity parameter EC50. The PK/PD model was evaluated and subjected external validation. Finally, simulations were performed to predict the antitumor efficacy of DEX combined with SUL under various dose regimens, where changing dosing frequency of SUL had little effect, while the antitumor efficacy was predicted to be improved when DEX was given more frequently. The established PK/PD model in this study quantitatively characterizes the antitumor efficacy of the DEX combined with SUL as well as their synergism, and the simulations could provide reference for dose optimization of the combination in future studies.

Effectiveness of Phenolic Antioxidants in Experimental Model of Benign Prostatic Hyperplasia.

Experimental model of sulpiride-provoked benign prostatic hyperplasia was employed to comparatively assess the effect of phenolic antioxidants (dihydroquercetin, p-thyrozol, dibornol, and prostagenin) on prostate morphology. All examined agents decreased the degree of hyperplasia in acinar epithelium; the greatest efficacy was demonstrated by prostagenin. Moreover, dihydroquercetin and p-thyrozol increased the cross-section area of acinar lumina and prostate volume, which is inadmissible in this pathology. These results suggest that the use of phenolic antioxidants in the therapy of benign prostatic hyperplasia should be strictly controlled.

Morphological Assessment of Prostatotropic Activity of (3,5-Dimethyl-4-Hydroxy)Benzyl Thiododecane on a Model of Benign Prostatic Hyperplasia in Rats.

Prostatotropic activity of (3,5-dimethyl-4-hydroxy)benzyl thiododecane (T-DD) was evaluated on a model of benign prostatic hyperplasia induced in Wistar rats by chronic (2 months) intraperitoneal administration of sulpiride (40 mg/kg). Morphometric analysis of the dorsolateral lobe of the prostate showed that after the 2-month course of intragastric T-DD (100 mg/kg) administered in parallel with sulpiride, the volume density of glandular epithelium decreased by 1.7 times, while the volume density of prostate stroma increased by 2 times. After administration of the reference drug Permixon at a dose of 50 mg/kg, the volume densities of epithelium decreased by 1.3 times and stromal volume density increased by 1.5 times. The observed effects are presumably related to suppression of 5α-reductase activity and modulation of estrogen receptors in the prostate.

The antipsychotics sulpiride induces fatty liver in rats via phosphorylation of insulin receptor substrate-1 at Serine 307-mediated adipose tissue insulin resistance.

Cumulative evidence has suggested that many antipsychotics cause metabolic abnormalities. Adipose tissue insulin resistance (Adipo-IR) contributes to the development and progress of metabolic abnormalities including fatty liver by inducing excessive free fatty acid release from adipose tissue. Sulpiride is an old antipsychotic still frequently used in many developing countries. However, its adverse metabolic effects remain poorly understood. Here, chronic administration of sulpiride (80 mg/kg, subcutaneously, once daily for 6 weeks) elevated fasting insulin concentration and the index of the homeostasis model assessment of insulin resistance in rats. More importantly, sulpiride increased hepatic triglyceride accumulation and Oil Red O-stained area, indicating the induction of fatty liver by sulpiride. Sulpiride also increased plasma non-esterified fatty acid concentrations at the baseline and during an oral glucose tolerance test, the Adipo-IR index, and adipocyte size. Adipose gene expression profile revealed that sulpiride decreased mRNA and protein expression of insulin receptor substrate (IRS)-1, but not IRS-2. Furthermore, sulpiride increased phosphorylation of both Ser307 in IRS-1 and Ser473 in Akt at baseline. Co-treatment with bromocriptine (a dopamine D2 receptor agonist) attenuated sulpiride-induced hyperprolactinemia, but it was without effect on insulin resistance and fatty liver. Therefore, the present results suggest that sulpiride induces fatty liver in rats via phosphorylation of IRS-1 at Ser307-mediated adipose tissue insulin resistance, in which dopamine D2 receptor is possibly not involved. Our findings may provide new insights into the mechanisms underlying the steatotic effect of the old antipsychotic.

D1, but not D2, receptor blockade within the infralimbic and medial orbitofrontal cortex impairs cocaine seeking in a region-specific manner.

Evidence suggests that the infralimbic cortex (IL), a subregion of the ventromedial prefrontal cortex (vmPFC), suppresses cocaine-seeking behavior in a self-administration paradigm, whereas the more anterior vmPFC subregion, the medial orbitofrontal cortex (mOFC), has received very little attention in this regard. Despite the established dopaminergic innervation of the vmPFC, whether dopamine receptor blockade in each subregion alters the reinstatement of cocaine seeking is unclear. To address this issue, male Sprague-Dawley rats underwent 2 weeks of cocaine self-administration, followed by extinction training and reinstatement testing. Immediately prior to each reinstatement test, rats received microinjections of the D1 receptor antagonist SCH 23390, the D2 receptor antagonist sulpiride or their respective vehicles. D1 receptor blockade in the IL reduced cued reinstatement but had no effect on cocaine prime and cue + cocaine-prime reinstatement, whereas D2 receptor blockade in the IL had no effect on reinstatement. For the mOFC, however, D1 receptor blockade reduced cocaine seeking in all reinstatement types, whereas blocking D2 receptors in the mOFC had no effect on any form of cocaine seeking. These findings suggest different roles for D1 receptors in the IL versus the mOFC in regulating cocaine-seeking behavior. Moreover, even as previous work indicates that IL inactivation does not affect reinstatement but, rather, induces cocaine seeking during extinction, the present findings suggest that dopamine receptor activation in the IL is necessary for cocaine seeking under some circumstances.

Contribution of dopamine neurotransmission in proconvulsant effect of Toxoplasma gondii infection in male mice.

Epilepsy is one of the most common neurologic disorders worldwide with no distinguishable cause in 60% of patients. One-third of world's population is infected with Toxoplasma gondii (T. gondii). This intracellular parasite has high tendency to excitable cells including neurons. We assessed seizure susceptibility and involvement of dopaminergic system in male mice with acute and chronic T. gondii infection. Mice were infected by intraperitoneal injection of T. gondii cysts. Acute and chronic stages of infection were determined by quantification of SAG1/BAG1 transcripts and level of repetitive REP-529 sequence in the brain of mice by real-time PCR. Threshold of clonic seizures was measured by tail vein infusion of pentylenetetrazole. The infected mice were pretreated with D1 and D2 dopamine receptor antagonists, and seizure threshold was measured. Moreover, seizure threshold was determined after treatment of toxoplasmosis by sulfamethoxazole and trimethoprim. SAG1 level reached the maximum at week 2 after infection and then declined. The maximum level of BAG1 was observed at the week 3 and preserved till the week 8. REP-529 was detected at first week after infection, reached maximum at the week 3 and kept at this level till the eighth week. Threshold of seizures significantly decreased in both acute and chronic phases of infection. D1 and D2 receptors antagonists inhibited proconvulsant effect of toxoplasmosis. Chemotherapy inhibited parasite growth and multiplication, and returned seizure susceptibility to the level of non-infected mice. Dopaminergic neurotransmission participates in proconvulsant effect of T. gondii. The effect of parasite is eliminated by antibiotic therapy. © 2017 Wiley Periodicals, Inc.

Multiple drug transporters mediate the placental transport of sulpiride.

Sulpiride is a typical antipsychotic drug for the treatment of schizophrenia, depression and other psychological disorders. It has been proven that a small amount of sulpiride could cross the human placenta using an ex vivo placental perfusion model. However, the placental transfer mechanism has not been elucidated. Considering the structure of sulpiride, we speculated that the transporters expressed in placenta might be involved in sulpiride uptake across the blood-placenta barrier. The aim of our study was to determine which transporters contributed to the placental transfer of sulpiride. Our results revealed that sulpiride was a substrate of human organic cation transporter (hOCT) 3, human multidrug resistance protein (hMDR) 1 and human breast cancer resistance protein (hBCRP) using transfected cells expressing respective transporters. In addition, the accumulation of sulpiride in BeWo cells (a human choriocarcinoma cell line) was obviously affected by inhibitors of carnitine/organic cation transporter (OCTN) 2, MDR1 and BCRP. The accumulation of sulpiride in primary human trophoblast cells was obviously affected by inhibitors of OCT3, OCTN1 and OCTN2. The above results indicate that hOCTN1 and hOCTN2 likely contribute to the sulpiride uptake from maternal circulation to trophoblast cells, while hMDR1 and hBCRP mediate the efflux from trophoblast cells to maternal circulation, and hOCT3 probably is involved in the bidirectional transport of sulpiride between the placenta and fetal blood.

Multiple organic cation transporters contribute to the renal transport of sulpiride.

Sulpiride, a selective dopamine D2 receptor blocker, is used widely for the treatment of schizophrenia, depression and gastric/duodenal ulcers. Because the great majority of sulpiride is positively charged at physiological pH 7.4, and ~70% of the dose recovered in urine is in the unchanged form after human intravenous administration of sulpiride, it is believed that transporters play an important role in the renal excretion of sulpiride. The aim of the present study was to explore which transporters contribute to the renal disposition of sulpiride. The results demonstrated that sulpiride was a substrate of human carnitine/organic cation transporter 1 (hOCTN1) and 2 (hOCTN2), human organic cation transporter 2 (hOCT2), human multidrug and toxin efflux extrusion protein 1 (hMATE1) and 2-K (hMATE2-K). Sulpiride accumulation from the basolateral (BL) to the apical (AP) side in MDCK-hOCT2/pcDNA3.1 cell monolayers was much greater than that in MDCK-hOCT2/hMATE1 cells, and cimetidine dramatically reduced the intracellular accumulation of sulpiride from BL to AP. In addition, the accumulation of sulpiride in mouse primary renal tubular cells (mPRTCs) was markedly reduced by inhibitors of Oct2 and Octns. The results implied that OCTN1, OCTN2, OCT2, MATE1 and MATE2-K probably contributed to the renal transfer of sulpiride, in which OCT2 mediated the uptake of sulpiride from the bloodstream to the proximal tubular cells, while MATEs contributed to the sulpiride efflux from the proximal tubular cells to the renal lumen, and OCTNs participated in both renal secretion and reabsorption.

Analysis of risk factors influencing the outcome of the Epley maneuver.

Benign paroxysmal positional vertigo (BPPV) is the most frequent type of vertigo. The treatment of canalithiasis of the posterior semicircular canal consists in performing a particle-repositioning maneuver, such as the Epley maneuver (EM). However, the EM is not effective in all cases. The objective of this study is to identify risk factors, which predict the EM failure, among the clinical variables recorded in anamnesis and patient examination. This is an observational prospective multicentric study. All patients presenting with BPPV were recruited and applied the EM and appointed for a follow-up visit 7 days later. The following variables were recorded: sex, age, arterial hypertension, diabetes, hyperlipidemia, smoking habit, alcohol consumption, migraine, osteoporosis, diseases of the inner ear, previous ipsilateral BPPV, previous traumatic brain injury, previous sudden head deceleration, time of evolution, sulpiride or betahistine treatment, experienced symptoms, outcome of the Halmagyi maneuver, laterality, cephalic hyperextension of the neck, intensity of nystagmus, intensity of vertigo, duration of nystagmus, occurrence of orthotropic nystagmus, symptoms immediately after the EM, postural restrictions, and symptoms 7 days after the EM. Significant differences in the rate of loss of nystagmus were found for six variables: hyperlipidemia, previous ipsilateral BPPV, intensity of nystagmus, duration of nystagmus, post-maneuver sweating, and subjective status. The most useful significant variables in the clinical practice to predict the success of the EM are previous BPPV and intensity of nystagmus. In the other significant variables, no physiopathological hypothesis can be formulated or differences between groups are too small.

In Vivo Evaluation of a PEO-Gellan Gum Semi-Interpenetrating Polymer Network for the Oral Delivery of Sulpiride.

In this study, an optimized epichlorohydrin-crosslinked semi-interpenetrating polymer network xerogel matrix system (XePoMas) for the controlled delivery of sulpiride was prepared. The ability of XePoMas to sustain drug release was determined by in vitro and in vivo drug release experiments. Swelling of the xerogel over the 24-h experimental period ranged from 346 to 648%; swelling was observed to increase exponentially over the initial 8 h. In vitro drug release depicted a linear zero order drug release profile with an R 2 value of 0.9956. The ability of the fabricated XePoMas to sustain drug release and enhance bioavailability of sulpiride in vivo was investigated by evaluating the plasma drug concentration over 24 h in the large pig model. The optimized XePoMas formulation was shown to increase intestinal absorption of sulpiride to a greater extent than the marketed product in vivo, with a C max of 830.58 ng/mL after 15 h.

Influence of sulpiride treatment on the level of prolactin and immunoglobulins in the peripheral blood of mares during the postpartum period.

The aim of this study was to determine the effect of increased levels of prolactin (PRL) on the concentration of immunoglobulins in the blood, colostrum and milk of mares. The study was conducted on 12 mares of the Polish Pony breed (6 in the control and 6 in the experimental group). To induce hyperprolactinaemia in mares of the experimental group, 750 mg sulpiride was administered orally once a day. The initial PRL concentration was 52.22 ± 11.21 ng/ml in the control group and 49.39 ± 10.12 ng/ml in the experimental group. In the subsequent days, the concentration of PRL dynamically changed. Statistical analysis showed highly significant differences (P < 0.01) between the groups. The concentration of immunoglobulins in the blood plasma was at the same level during the experimental period (32.97-29.08 mg/ml in the experimental group and 28.60-18.11 mg/ml in the control group). Statistical analysis showed highly significant differences between the groups in blood plasma immunoglobulin level (P < 0.01). The highest immunoglobulin concentration was obtained within 12 h after parturition in the control and the experimental group (23.49 ± 2.12 mg/ml and 26.94 ±1.72 mg/ml, respectively). The lowest values were obtained on day 12 after parturition in the experimental group (10.15 mg/ml ± 1.47 mg/ml) and on day 7 after parturition in the control group (14.30 mg/ml ± 2.48 mg/ml). In conclusion, this study did not provide evidence that the lactogenic hormone prolactin is involved in the transfer of immunoglobulins into the colostrum in horses.

Dopaminergic drugs in type 2 diabetes and glucose homeostasis.

The importance of dopamine in central nervous system function is well known, but its effects on glucose homeostasis and pancreatic ß cell function are beginning to be unraveled. Mutant mice lacking dopamine type 2 receptors (D2R) are glucose intolerant and have abnormal insulin secretion. In humans, administration of neuroleptic drugs, which block dopamine receptors, may cause hyperinsulinemia, increased weight gain and glucose intolerance. Conversely, treatment with the dopamine precursor l-DOPA in patients with Parkinson's disease reduces insulin secretion upon oral glucose tolerance test, and bromocriptine improves glycemic control and glucose tolerance in obese type 2 diabetic patients as well as in non diabetic obese animals and humans. The actions of dopamine on glucose homeostasis and food intake impact both the autonomic nervous system and the endocrine system. Different central actions of the dopamine system may mediate its metabolic effects such as: (i) regulation of hypothalamic noradrenaline output, (ii) participation in appetite control, and (iii) maintenance of the biological clock in the suprachiasmatic nucleus. On the other hand, dopamine inhibits prolactin, which has metabolic functions; and, at the pancreatic beta cell dopamine D2 receptors inhibit insulin secretion. We review the evidence obtained in animal models and clinical studies that posited dopamine receptors as key elements in glucose homeostasis and ultimately led to the FDA approval of bromocriptine in adults with type 2 diabetes to improve glycemic control. Furthermore, we discuss the metabolic consequences of treatment with neuroleptics which target the D2R, that should be monitored in psychiatric patients to prevent the development in diabetes, weight gain, and hypertriglyceridemia.

Comparative risk of oral ulcerations among antipsychotics users - population-based retrospective cohort study.

PURPOSE: The study aimed to evaluate the comparative risk of oral ulcerations among antipsychotic medications. METHODS: We analyzed the National Health Insurance Research Database of Taiwan and included patients newly initiated with a single antipsychotic agent including haloperidol, sulpiride, olanzapine, quetiapine, risperidone, or amisulpride during 2002 to 2010. The outcome of interest was oral ulceration, defined by the presence diagnoses of stomatitis and mucositis, aphthous-like ulceration and oral burns, or dispensing of stomatological corticosteroids included triamcinolone, dexamethasone, hydrocortisone, and prednisolone. We conducted Cox proportional hazards regression to compare the risks of oral ulceration among antipsychotics. RESULTS: The rate of oral ulcerations was highest in the amisulpride group (217.7 per 1000 person-year), followed by quetiapine (193.9 per 1000 person-year), olanzapine (161.9 per 1000 person-year), sulpiride (147.1 per 1000 person-year), risperidone (115.6 per 1000 person-year), haloperidol (107.5 per 1000 person-year) and aripiprazole (49.8 per 1000 person-year). Compared with haloperidol users, the adjusted hazard ratio (AHR) was 1.40 (95% CI, 1.12-1.73) in olanzapine, 1.48 (95% CI, 1.30-1.69) in quetiapine, 1.27 (95% CI, 1.19-1.44) in sulpiride, 1.68 (95% CI, 0.97-2.59) in amisulpride, 1.02 (95% CI, 0.83-1.45) in risperidone, and 0.41 (95% CI, 0.24-0.72) in aripiprazole users by Cox regression model. CONCLUSION: Olanzapine, quetiapine, and sulpiride posed a higher risk, while aripiprazole posed a lower risk of oral ulcerations compared with haloperidol in subjects with newly initiated antipsychotic therapy. Risperidone and amisulpride tended to have higher risk of oral ulcerations, but this was not statistically significant.

Effects of sulpiride and ethylene glycol monomethyl ether on endometrial carcinogenicity in Donryu rats.

Sulpiride and ethylene glycol monomethyl ether (EGME) are known ovarian toxicants that stimulate prolactin (PRL) secretion, resulting in hypertrophy of the corpora lutea and increased progesterone (P4) production. The purpose of the present study was to investigate how the PRL stimulatory agents affected uterine carcinogenesis and to clarify the effects of PRL on endometrial adenocarcinoma progression in rats. Ten-week-old female Donryu rats were treated once with N-ethyl-N'-nitro-N-nitrosoguanidine (20 mg kg(-1) ), followed by treatment with sulpiride (200 ppm) or EGME (1250 ppm) from 11 weeks of age to 12 months of age. Sulpiride treatment inhibited the incidence of uterine adenocarcinoma and precancerous lesions of atypical endometrial hyperplasia, whereas EGME had no effect on uterine carcinogenesis. Sulpiride markedly prevented the onset of persistent estrus throughout the study period, and EGME delayed and inhibited the onset of persistent estrus. Moreover, sulpiride-treated animals showed high PRL and P4 serum levels without changes in the levels of estradiol-17ß, low uterine weights and histological luteal cell hypertrophy. EGME did not affect serum PRL and P4 levels. These results suggest that the prolonged low estradiol-17ß to P4 ratio accompanied by persistent estrous cycle abnormalities secondary to the luteal stimulatory effects of PRL may explain the inhibitory effects of sulpiride on uterine carcinogenesis in rats. Copyright © 2015 John Wiley & Sons, Ltd.