Deorphanizing an odorant receptor tuned to palm tree volatile esters in the Asian palm weevil sheds light on the mechanisms of palm tree selection

The Asian palm weevil, Rhynchophorus ferrugineus, is a tremendously important agricultural pest primarily adapted to palm trees and causes severe destruction, threatening sustainable palm cultivation worldwide. The host plant selection of this weevil is mainly attributed to the functional specialization of odorant receptors (ORs) that detect palm-derived volatiles. Yet, ligands are known for only two ORs of R. ferrugineus, and we still lack information on the mechanisms of palm tree detection. This study identified a highly expressed antennal R. ferrugineus OR, RferOR2, thanks to newly generated transcriptomic data. The phylogenetic analysis revealed that RferOR2 belongs to the major coleopteran OR group 2A and is closely related to a sister clade containing an R. ferrugineus OR (RferOR41) tuned to the non-host plant volatile and antagonist, α-pinene. Functional characterization of RferOR2 via heterologous expression in Drosophila olfactory neurons revealed that this receptor is tuned to several ecologically relevant palm-emitted odors, most notably ethyl and methyl ester compounds, but not to any of the pheromone compounds tested, including the R. ferrugineus aggregation pheromone. We did not evidence any differential expression of RferOR2 in the antennae of both sexes, suggesting males and females detect these compounds equally. Next, we used the newly identified RferOR2 ligands to demonstrate that including synthetic palm ester volatiles as single compounds and in combinations in pheromone-based mass trapping has a synergistic attractiveness effect to R. ferrugineus aggregation pheromone, resulting in significantly increased weevil catches. Our study identified a key OR from a palm weevil species tuned to several ecologically relevant palm volatiles and represents a significant step forward in understanding the chemosensory mechanisms of host detection in palm weevils. Our study also defines RferOR2 as an essential model for exploring the molecular basis of host detection in other palm weevil species. Finally, our work showed that insect OR deorphanization could aid in identifying novel behaviorally active volatiles that can interfere with weevil host-searching behavior in sustainable pest management applications.

Aphid populations are frequently infected with facultative endosymbionts

The occurrence of facultative endosymbionts has been studied in many commercially important crop pest aphids, but their occurrence and effects in non-commercial aphid species in natural populations have received less attention. We screened 437 aphid samples belonging to 106 aphid species for the eight most common facultative aphid endosymbionts. We found one or more facultative endosymbionts in 53% (56 of 106) of the species investigated. This likely underestimates the situation in the field because facultative endosymbionts are often present in only some colonies of an aphid species. Oligophagous aphid species carried facultative endosymbionts significantly more often than monophagous species. We did not find a significant correlation between ant tending and facultative endosymbiont presence. In conclusion, we found that facultative endosymbionts are common among aphid populations. This study is, to our knowledge, the first of its kind in the Netherlands and provides a basis for future research in this field. For instance, it is still unknown in what way many of these endosymbionts affect their hosts, which is important for determining the importance of facultative endosymbionts to community dynamics.

6E11, a highly selective inhibitor of Receptor-Interacting Protein Kinase 1, protects cells against cold hypoxia-reoxygenation injury

Necroptosis is a programmed cell death pathway that has been shown to be of central pathophysiological relevance in multiple disorders (hepatitis, brain and cardiac ischemia, pancreatitis, viral infection and inflammatory diseases). Necroptosis is driven by two serine threonine kinases, RIPK1 (Receptor Interacting Protein Kinase 1) and RIPK3, and a pseudo-kinase MLKL (Mixed Lineage Kinase domain-Like) associated in a multi-protein complex called necrosome. In order to find new inhibitors for use in human therapy, a chemical library containing highly diverse chemical structures was screened using a cell-based assay. The compound 6E11, a natural product derivative, was characterized as a positive hit. Interestingly, this flavanone compound: inhibits necroptosis induced by death receptors ligands TNF-α (Tumor Necrosis Factor) or TRAIL (TNF-Related Apoptosis-Inducing Ligand); is an extremely selective inhibitor, among kinases, of human RIPK1 enzymatic activity with a nM Kd; has a non-ATP competitive mode of action and a novel putative binding site; is weakly cytotoxic towards human primary blood leukocytes or retinal pigment epithelial cells at effective concentrations; protects human aortic endothelial cells (HAEC) from cold hypoxia/reoxygenation injury more effectively than necrostatin-1 (Nec-1) and Nec-1s. Altogether, these data demonstrate that 6E11 is a novel potent small molecular inhibitor of RIPK1-driven necroptosis.

Abstract PD1-06: Comparison of mutational landscapes of primary breast cancer and first metastatic relapse: Results from the ESOPE study

Background

Genomic profile of breast cancer metastases (M) may differ from that of the primary tumor (PT). In a multicenter prospective study (ESOPE, NCT 01956552) including 130 patients with biopsies of the first metastatic deposit, we have shown that luminal breast cancers are the most prone to phenotypical subtype changes (Comte et al, ASCO 2016#550). We report here the first results of a comparative PT/M targeted next generation sequencing (NGS) mutational analysis.

Methods

Of 130 patients, 117 paired PT/M samples obtained before any treatment were available for analysis. Targeted Sequencing was done using Illumina Hiseq2500 technology with a custom made 95 breast cancer associated genes panel. Sequence data were aligned to the human reference genome (hg19) using Bowtie2 algorithm. Median depth was 607X and 87% of targets achieved 100X depth. SNVs and indels were called using GATK UnifiedGenotyper. We retained COSMIC confirmed non synonymous, exonic/splice variants and observed at a frequency lower than 0,1% in population. Further confirmation of detected variants was performed with comparison to public databases (cbioportal, tumorportal), and potential pathogenicity was evaluated with 4 different public algorithms. We present here the results obtained from the first 35 matched PT/M samples (liver mets 68%), focusing analysis on 40 genes including PIK3CA (20 genes), ER (6 genes) and MAPK (11 genes) pathways, RUNX1, CDH1 and TP53 genes.

Results

Patients characteristics are representative of patients with first line metastatic breast cancer (Comte et al, ASCO 2016#550). Among the 40 genes analyzed in the 70 samples, we detected 134 somatic mutations (70 in PT and 64 in M) including 15 indels and 119 SNV. Among these 134 mutations there were 74 different mutations (66SNV and 8 indels) classified pathogenic for 26 and of unknown pathogenicity for 48 of them. We detected at least 1 mutation in 31 PT and in 28 M. Median numbers of mutations were 1 in PT (range 1-9) and 1 in M (range1-22) samples (p=0.295, Wilcoxon rank sum test). Top ten mutated genes in PT included PIK3CA, TP53, NCOR1, NF1, GATA3, CDH1, ERBB3, PTEN, HRAS, INPP4B. In M samples, the 10 top genes were PIK3CA, TP53, ERBB3, AKT3, CDH1, ERBB4, GATA3, INPP4B, MET, MTOR. Only 3 ESR1 mutations were detected, including 1 PT/M pair and 1 M. Beyond highly shared PIK3CA and TP53 mutations, overall crude PT/M discordance rate was 31%. Analysis by histological subtypes showed PT and M specific mutational profiles, suggesting a role in ERB gene family (notably ERBB3) and MAPK driven pathways in early metastatic progression. Specific metastatic site analysis suggested enrichment in MAPK pathway mutations in liver metastases when compared to other sites. Variant allelic fractions were globally not significantly different between PT and M samples.

Conclusion

In this prospective multicenter series of systematic biopsies of first metastases, we report a targeted mutational analysis of matched PT and M samples not modified by previous therapy exposure. Early analyses suggest specific genotypical changes according to tumor subtype and/or metastatic site. Extended and updated results will be reported at the meeting.

Citation Format: Cottu PH, Boulai A, Callens C, Baulande S, Legoix-Ne P, Bernard V, Vincent-Salomon A, Benhamo V, Brain EGC, Chemlali W, Campone M, Bachelot TD, Giacchetti S, Bonneterre J, Bidard F-C, Servois V, Comte A, Belin L, Sigal B, Bièche I. Comparison of mutational landscapes of primary breast cancer and first metastatic relapse: Results from the ESOPE study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD1-06.

Abstract P2-05-06: Clinical utility of systematic biopsy of first metastatic event in breast cancer: Results from a prospective multicenter trial

BACKGROUND: Cumulative evidence for phenotypic and molecular heterogeneity between primary breast cancer (BC) site and matched metastasis (mets) has been obtained in retrospective studies. Current expert consensus suggests performing biopsies of mets, but clinical utility and cost are unknown. The primary objective of the ESOPE study (NCT01956552) was to compare the phenotype and genotype of the primary tumor (PT) with those of matched mets at time of first distant relapse, before the start of any treatment, in order to optimize the treatment of mets

PATIENTS and METHODS: Between Nov. 2010 and Sept. 2013, we conducted a prospective multicenter study on BC patients (pts) with diagnosis of first mets. All pts were to have available Formalin-Fixed Paraffin-Embedded (FFPE) PT sample and mets accessible to either percutaneous or surgical sampling. All tissue samples were centrally analyzed with immunohistochemistry (ER, PgR, HER2, and Ki67) and FISH when indicated. Frozen samples were stored for further analyses. We recorded intended therapeutic decision before and after biopsy.

RESULTS: Of 93 pts included, 89 were eligible for biopsy. Median age was 57 years (28-81); median interval between PT and mets was 42 months (0-211), including 14 pts with novo metastatic breast cancer. Mets biopsy was performed in 85 pts (96%, refusal n=2, not feasible n=2). Toxicity was limited to only 1 grade 1 hemorrhage. Sampled sites were liver (44%), lung (16%), bone (13%), lymph node (13%), skin/muscle/chest wall (9%), ovary/peritoneum (4%), and adrenal gland (1%). PT was not available in 4 pts; mets biopsy was non contributive in 6 pts but led to a diagnosis of second primary cancer in 3 pts.

In 72 pts with matched PT and mets, PT were luminal A (n=11), luminal B (n=33), triple negative (n=13), HER2 (n=13), non-evaluable (n=2). Mets were luminal A (n=6), luminal B (n=30), triple negative (n=16), HER2 (n=14), non-evaluable (n=6). Discrepancy rates were: ER 18% [kappa for concordance =0.6, CI 95 % (0.42-0.77)], PgR: 39% [kappa=0.19, CI 95% (0.01-0.39)], Her2: 4% [kappa=0.86, CI 95% (0.7-1)], Ki67: 25% [kappa=0.19, CI 95% (-0.09; 0.49)].

The most frequent discrepancy rate was observed in pts with lum A PT, as only 3/10 developed Lum A mets. HER2 and triple negative were the most stable subtypes (12/13 and 12/12 respectively). Most importantly, mets biopsy led to a change in therapeutic decision in 25 pts (independent evaluation by 2 oncologists). Additional comparative targeted NGS analyses are ongoing on a first subset of 54 FFPE paired samples, and parallel whole exome sequencing is planned on 38 paired samples with available constitutional DNA.

CONCLUSION: Comparative analysis of breast cancer PT and first mets is routinely feasible, with very low morbidity and a significant impact for patients' management: 29% had a second cancer diagnosis or were proposed a therapeutic change. Furthermore, this study will provide additional data on quality and quantity of tissue available for molecular analysis, and ultimately in terms of cost-efficacy.

Citation Format: Comte A, Sigal-Zafrani B, Belin L, Bièche I, Callens C, Diéras V, Bidard F-C, Mariani O, Servois V, Szwarc D, Vincent-Salomon A, Brain ECG, Cottu PH. Clinical utility of systematic biopsy of first metastatic event in breast cancer: Results from a prospective multicenter trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-06.

PHLDA2 is an imprinted gene in cattle

Genomic imprinting is an epigenetic non-Mendelian phenomenon found predominantly in placental mammals. Imprinted genes display differential expression in the offspring depending on whether the gene is maternally or paternally inherited. Currently, some 100 imprinted genes have been reported in mammals, and while some of these genes are imprinted across most mammalian species, others have been shown to be imprinted in only a few species. The PHLDA2 gene that codes for a pleckstrin homology-like domain, family A (member 2), protein has to date been shown to be a maternally expressed imprinted gene in humans, mice and pigs. Genes subject to imprinting can have major effects on mammalian growth, development and disease. For instance, disruption of imprinted genes can lead to aberrant growth syndromes in cloned domestic mammals, and it has been demonstrated that PHLDA2 mRNA expression levels are aberrant in the placenta of somatic clones of cattle. In this study, we demonstrate that PHLDA2 is expressed across a range of cattle foetal tissues and stages and provide the first evidence that PHLDA2 is a monoallelically expressed imprinted gene in cattle foetal tissues, and also in the bovine placenta.

Time course of odorant- and trigeminal-induced activation in the human brain: an event-related functional magnetic resonance imaging study

It is well known that most odorants stimulate the trigeminal system but the time course of the brain regions activated by these chemical stimulations remains poorly documented, especially regarding the trigeminal system. This functional magnetic resonance imaging (fMRI) study compares brain activations resulting from the contrast between two odorant conditions (one bimodal odor and one relatively pure olfactory stimulant) according to the duration of the stimulation (i.e. one inhalation, or three or six successive inhalations). The results show striking differences in the main brain regions activated according to these durations. The caudate nucleus and the orbitofrontal cortex are only involved in short-duration stimulations, and the posterior insular cortex and post-central gyrus (SI) are only activated by long duration stimulations. Different regions of the frontal, temporal and occipital lobe are activated depending on the duration but mainly during medium-duration stimulations. These results expand on the findings of previous studies and contribute to the description of temporal networks in trigeminal perception.

Plutonium in the environment: key factors related to impact assessment in case of an accidental atmospheric release

This paper deals with plutonium and key factors related to impact assessment. It is based on recent work performed by CEA which summarize the main features of plutonium behaviour from sources inside installations to the environment and man, and to report current knowledge on the different parameters used in models for environmental and radiological impact assessment. These key factors are illustrated through a case study based on an accidental atmospheric release of Pu in a nuclear facility.

Development of a database: DACTARI for a radiotoxic element ranking methodology

Dosimetric impact studies aim at evaluating potential radiological effects of chronic or acute releases from nuclear facilities. A methodology for ranking radionuclides (RN) in terms of their health-related impact on the human population was first developed at CEA with specific criteria for each RN that could be applied to a variety of situations. It is based, in particular, on applying physico-chemical criteria to the complete RN inventory (present in the release or in the source term) and on applying norms related to radiation protection and chemical toxicology. The initial step consisted in identifying and collecting data necessary to apply the methodology, with reference to a previous database of long-lived radionuclides (LLRN, with half-lives ranging from 30 to 10(14) y) containing 95 radionuclides. The initial results have allowed us to identify missing data and revealed the need to complete the study for both toxic and radiotoxic aspects. This led us to the next step, developing a specific database, DAtabase for Chemical Toxicity and Radiotoxicity Assessment of RadIonuclides (DACTARI), to collect data on chemical toxicity and radiotoxicity, including acute or chronic toxicity, the chemical form of the compounds, the contamination route (ingestion, inhalation), lethal doses, target organs, intestinal and maternal-foetal transfer, drinking water guidelines and the mutagenic and carcinogenic properties.

Left ventricular ejection fraction calculation from automatically selected and processed diastolic and systolic frames in short-axis cine-MRI

The calculation of the left ventricular ejection fraction (LVEF) is dependent upon the accurate measurement of diastolic and systolic left ventricular volumes. Although breath-hold cine magnetic resonance imaging (MRI) allows coverage of the whole cardiac cycle with an excellent time resolution, many authors rely on the visual selection of diastolic and the systolic short-axis slices in order to reduce the postprocessing time. An automatic method was developed to detect the endocardial contour on each image, allowing an automatic selection of the systolic frame. The calculated ejection fraction was compared with radionuclide ventriculography (RNV). Sixty-five patients were examined using an electrocardiogram (ECG)-gated gradient echo sequence. Among these examinations, manual and automatic processing with MRI were compared when the time of the systolic frame concorded. Good correlations have been found between the automatic MRI approach and RNV, and between manual and automatic processing on MRI alone. The results show that the automatic determination of the ejection fraction is feasible, and should constitute an important step toward a larger acceptance of MRI as a routine tool in heart disease imaging. One major benefit of using automatic postprocessing is that it may eliminate the visual choice of the systolic frame, inaccurate in more than 50% of the studied patients.

[Role of visual analysis of first-pass contrast-enhanced MRI in reperfused myocardial infarction]

The aim of this work is to evaluate the relationship between improvement of regional myocardial function and visual analysis of contrast-enhanced (CE) MRI in patients after acute myocardial infarction. MRI was performed on 19 patients 1 and 11 weeks after a reperfused acute myocardial infarction. Perfusion data (first-pass images [FPI] and delayed CE images) were acquired after an intravenous bolus of gadolinium-DTPA and visually analyzed using a 17 segment model. Each segment was then classified in 3 groups, according to the presence or absence of FPI and CE patterns at baseline study: group 0: normal-appearing segments; group 1: segments with delayed hyper-enhancement but no early hypo-enhancement; group 2: segments with early hypoenhancement. Relative Wall thickening (RWT) was analyzed in each segment and its improvement evaluated in each group. Between first MRI and follow-up study, a significant improvement of RWT occurred in group 1 (mean +/- SD) [from 43.43 +/- 26.59% to 76.71 +/- 47.38%; p = 0.001] but not in group 2 (from 32.73 +/- 25.58% to 39.57 +/- 30.57%; p = NS). In group 0, RWT despite normal value at baseline study exhibited a significant improvement at follow-up (from 65.23 +/- 46.52% to 79.73 +/- 48.46%; p = 0.0015). In conclusion, the combined analysis of early and delayed perfusion abnormalities in MRI in the week following myocardial infarction can predict myocardial viability and allows in the future an evaluation of the efficacy of perfusion therapy.

[Magnetic resonance imaging early after acute myocardial infarction. A visual analysis of myocardial perfusion based on a 17 segment model]

Magnetic resonance imaging allows an accurate calculation of the left ventricular ejection fraction and left ventricular volumes. Additionally, it makes possible to assess myocardial perfusion after gadolinium chelate injection. Late after the injection, the presence of a myocardial hyper-enhancement can be visualized. The present study has used the 17 segment standardized nomenclature for tomographic imaging of the heart as recommended for all cardiac imaging modalities. Sixty nine patients were studied after a revascularised myocardial infarction. All patients had Timi grade 3 flow in the infarct-related artery after therapy. Regional and global function was studied using cine MR short axis slices. The gadolinium chelate first pass was scored using a 5 level scale reflecting the transmural extent of the segmental myocardial enhancement. The delayed enhancement due to gadolinium accumulation in the myocardium 10 min post injection was scored in the same manner. Left ventricular ejection fraction was 51 +/- 13%. Segmental thickening parameters (systolic thickness, absolute thickening and relative thickening) appeared statistically related to the hypoperfusion and delayed enhancement scores. Absolute myocardial thickening varied from 4.8 +/- 2.7 mm in the myocardial segments free of any delayed enhancement to 2.4 +/- 2.1 mm in segments presenting with a transmural extent of the delayed hyper-enhancement. Scores obtained after gadolinium injection were also well correlated with the global left ventricular function (r = 0.65, p < 0.01 for late enhancement). Magnetic resonance imaging of the heart allows a precise characterisation of revascularised myocardium which makes this technique very attractive for evaluating the treatments designed to improve myocardial microperfusion.

[Early study of myocardial perfusion with MRI in revascularized infarcts]

The aim of this work is to study the regional myocardial perfusion by MRI early after revascularised myocardial infarction and to compare it with regional function. This prospective work has included 15 patients with acute first myocardial infarction that was precociously revascularised. A myocardial MRI was performed between D2 and D10 after myocardial infarction. The regional myocardial thickening was evaluated from cine-MRI sequences. For the study of myocardial perfusion, the first pass of the contrast agent was analysed from curves of the signal evolution versus time. The signal enhancement on late images acquired 10 minutes after the perfusion of the contrast agent was also evaluated. Among 384 studied myocardial segments, those with a normal gadolinium first pass curve had a relative thickening of 46 +/- 38%. The segments with a severely reduced first pass kinetic have a markedly reduced relative thickening (14 +/- 20%) in relation with myocardial hypoperfusion. The myocardial enhancement is frequently seen in the infarct territory and appears related to a reduced regional contractility. The myocardium is enhanced on late images in 12% of the normally perfused segments. These segments have a mildly reduced wall thickening (3.36 +/- 2.84 mm vs 4.42 +/- 2.83 mm). The segmental contractility in a reperfused myocardial infarction appears to depend both on the myocardial perfusion which reflects the microvascularisation and on the myocardial enhancement which is linked to myocardial structural alterations. MRI appears to be an adequate method to evaluate these abnormalities and allows an easy assessment of the no-reflow phenomenon, if present.

Oxygen monitoring in supercritical carbon dioxide using a fibre optic sensor

Investigations of enzymatic reactions in supercritical CO(2) are often hindered by the high pressure involved in these processes, making reaction monitoring extremely difficult. This paper describes the implementation of a fiber optic based oxygen sensor into a high pressure reactor for supercritical carbon dioxide. The sensor is pressure resistant, working in supercritical carbon dioxide and reusable after depressurisation. The sensor signal is found to be affected by pressure changes, but stable at constant pressure. Oxygen concentration in supercritical CO(2) is monitored using the disproportionation of hydrogen peroxide as a simple oxygen producing reaction.

Modulation by external Ca2+ and nicardipine of Ca2+ influx and cytosolic concentration in human erythrocytes

Variations of Ca2+ influx (evaluated by the initial rate of 45Ca2+ uptake) and cytosolic free Ca2+ concentration ([Ca2+]i, measured with fura-2) were investigated in human erythrocytes. When external Ca2+ concentration ([Ca2+]o) rose from 1 to 2 mM, the initial rate of Ca2+ influx nearly doubled whereas [Ca2+]i increased only by 15%. Nicardipine dose-dependently decreased both initial rate of Ca2+ influx and [Ca2+]i (up to 53 and 18%. respectively at 10(-6) M). The less marked changes in [Ca2+]i than in Ca2+ influx indicate a partial adjustment of the Ca2+ extruding-pump activity to of Ca2+ influx. In vivo administration of nicardipine reduced [Ca2+]i only when its initial value exceeded 80 nM and prevented the rise in [Ca2+]i induced by the increase in [Ca2+]o. Our results indicate that nicardipine may reduce Ca2+ influx in human erythrocytes and participate in the control of [Ca2+]i when elevated.

Binding of [3H]isradipine (PN 200-110) on smooth muscle cell membranes from different bovine arteries

The binding of [3H]isradipine [( 3H]PN 200-110), a new dihydropyridine (DHP) calcium blocker on smooth muscle cell (SMC) membranes from different bovine arteries was saturable with comparable high affinities but different binding site densities (Bmax). The data were fitted to a model that provided a common estimation for the dissociation constant (Kd = 0.46 nM, SD = 0.03) but different Bmax values. Two groups of arteries could be distinguished, large-sized with high Bmax (aorta, 149 fmol/mg, SD = 4; intrapulmonary, 134 fmol/mg, SD = 4) and medium-sized with lower Bmax (mesenteric, 67 fmol/mg, SD = 2; internal carotid, 50 fmol/mg, SD = 2; renal artery, 29 fmol/mg, SD = 2). The Kd values were similar to those previously reported, but the Bmax value on aorta SMC was higher than usually reported with other DHPs, showing that isradipine was a high full antagonist of calcium channel. Our results also suggest that the increase in arterial compliance induced by DHPs will probably be more important on large-sized arteries than on medium-sized arteries because of higher DHP binding.

Binding of (+)-PN 200-110 to rat pituitaries and to normal and adenomatous human pituitaries

Endocrine cells possess voltage-sensitive Ca2+ channels involved in the modulation of hormonal secretion. Using the dihydropyridine, (+)-PN 200-110, we have investigated the binding characteristics of this ligand to pituitary membrane Ca2+ channels from normal rat, normal and adenomatous human pituitaries. [3H]PN 200-110 binds specifically to rat pituitary membranes to one class of sites (Kd = 0.41 +/- 0.10 mM; Bmax = 39 +/- 1.3 fmol/mg protein). At 37 degrees C, equilibrium is reached in 45 min and half-life of the binding is 13 min. No significant changes were observed for either the Kd or Bmax values between normal rat and human pituitaries or between the different types of adenomas (GH- and PRL-secreting and non-secreting). As the secretory activity of the pituitary adenomas, involving Ca2+ mobilization, varies from one adenoma to another, our results could indicate that, if there is a modified regulation of Ca2+ entry in the adenomas, it may not be related to a varying number of calcium channels, at least the channels labeled by the dihydropyridine (+)-PN 200-110.