Interleukin-1 beta enhances corticosterone secretion by acting directly on the rat adrenal gland

Interleukin-1 (IL-1), a monokine released by activated monocytes during the acute phase of the inflammatory responses, has been reported to enhance hypophyseal ACTH release mainly by stimulating hypothalamic CRF secretion. We investigated a possible direct effect of IL-1 beta on the adrenal gland of the rat. IL-1 beta was found to dose-dependently (4-8 micrograms/kg) raise corticosterone (B) blood concentration in hypophysectomized rats, without inducing any significant increase in the level of circulating ACTH. IL-1 beta did not affect B production by either isolated rat inner adrenocortical cells or fragments of adrenocortical autotransplants lacking chromaffin cells, but dose-dependently (10(-8)-10(-6) M) enhanced that by adrenal slices including both cortex and medulla. The secretory effect of IL-1 beta (10(-6) M) was completely blocked by both alpha-helical-CRF (10(-6) M) and corticotropin-inhibiting peptide (10(-6) M), two competitive inhibitors which (at these concentrations) were able to annul B response of adrenal slices to CRF (10(-6) M) and ACTH (10(-8) M), respectively. In light of many findings indicating that adrenal medulla contains and releases CRF and numerous POMC-derived peptides (including ACTH), the hypothesis is advanced that the mechanism underlying the direct secretory effect of IL-1 beta on the adrenal gland may involve the activation of an intraadrenal CRF/ACTH system.

Anatomy of the deep fascia of the upper limb. Second part: study of innervation

Analysis of specimens taken from different areas of the deep fascia in 20 upper limbs was made in order to establish which kind of nerve fibres and endings are present in the deep muscular fascia. The flexor retinaculum and the lacertus fibrosus were also evaluated because they are anatomically hardly separable from the deep muscular fascia, although they have different functions. In particular, specimens were taken at the level of: (a) the expansion of pectoralis major onto the bicipital fascia, (b) the middle third of the brachial fascia, (c) the lacertus fibrosus, (d) the middle third of the antebrachial fascia, (e) the flexor retinaculum. This study demonstrated an abundant innervation of the fascia consisting in both free nerve endings and encapsulated receptors, in particular, Ruffini and Pacini corpuscles. However, differences in innervation were verified: the flexor retinaculum was resulted the more innervated element whilst lacertus fibrosus and the pectoralis major expansion the less innervated. These results suggest that the retinaculum has more a perceptive function whereas the tendinous expansions onto the fascia have mostly a mechanical role in the transmission of tension. The hypothesis that the fascia plays an important role in proprioception, especially dynamic proprioception, is therefore advanced. In fact, the fascia is a membrane that extends throughout the whole body and numerous muscular expansions maintain it in a basal tension. During a muscular contraction these expansions could also transmit the effect of the stretch to a specific area of the fascia, stimulating the proprioceptors in that area.

Endothelin adrenocortical secretagogue effect is mediated by the B receptor in rats

We investigated the gene expression and localization of endothelin-1 (ET-1) receptor subtypes ET(A) and ET(B) in the rat adrenal cortex as well as their involvement in the corticosteroid secretagogue effect of ET-1 in vitro. Reverse transcription-polymerase chain reaction with primers specific for ET(A) and ET(B) cDNAs demonstrated the expression of both receptor genes in homogenates of adrenocortical tissue. However, in isolated zona glomerulosa and zona fasciculata cells, only ET(B) mRNA was detected. Autoradiographic examination of the selective displacement of 125I-ET-1 binding by BQ-123 and BQ-788 (specific ligands for ET(A) and ET(B), respectively) indicated that zona glomerulosa possesses both ET(A) and ET(B), whereas zona fasciculata is exclusively provided with ET(B). ET-1 enhanced in a concentration-dependent manner aldosterone and corticosterone secretions of dispersed zona glomerulosa and zona fasciculata cells, respectively. The ET(B) antagonist BQ-788 markedly reduced the secretory response of zona glomerulosa cells and completely suppressed that of zona fasciculata cells, whereas the ET(A) antagonist BQ-123 was ineffective. These findings indicate that in the rat, the adrenocortical secretagogue action of ET-1 is mediated by the ET(B) receptor subtype and that the ET(A) receptor is not directly involved in such an effect.

Gene expression, localization, and characterization of endothelin A and B receptors in the human adrenal cortex

Compelling evidence indicates that the endothelium-derived potent vasoconstrictor endothelin-1 (ET-1) stimulates aldosterone secretion by interacting with specific receptors. Although two different ET-1 receptors have been identified and cloned, the receptor subtype involved in mediating aldosterone secretion is still unknown. Accordingly, we wished to investigate whether the genes of ET-1 and of its receptors A and B are expressed in the normal human adrenal cortex. We designed specific primers for ET-1 and the ETA and ETB receptors genes and developed a reverse transcription polymerase chain reaction (RT-PCR) with chemiluminescent quantitation of the cDNA. In addition, we carried out 125I ET-1 displacement studies with cold ET-1, ET-3 and the specific ETA and ETB ligands BQ123 and sarafotoxin 6C. Localization of each receptor subtype was also investigated by autoradiography. Binding experiments were first individually analyzed by Scatchard and Hofstee plot and then coanalyzed by the nonlinear iterative curve fitting program Ligand. Histologically normal adrenal cortex tissue, obtained from kidney cancer patients (n = 7), and an aldosterone-producing adenoma (APA), which is histogenetically derived from the zona glomerulosa (ZG) cells, were studied. Results showed that the ET-1, ETA and ETB mRNA can be detected by RT-PCR in all adrenal cortices as well as in the APA. The best fitting of the 125I ET-1 displacement binding data was consistently provided by a two-site model both in the normal adrenal cortex (F = 22.1, P < 0.0001) and in the APA (F = 18.4, P < 0.0001). In the former the density (Bmax) of the ETA and ETB subtype was 2.6 +/- 0.5 pmol/mg protein (m +/- SEM) and 1.19 +/- 0.6, respectively. The dissociation constant (Kd) of ET-1, ET-3, S6C, and BQ-123 for each receptor subtype resulted to be within the range reported for human tissue for the ETA and ETB receptors. In the APA tissue the Bmax tended to be lower (1.33 and 0.8 pmol/mg protein, for the ETA and ETB, respectively) but the Kd were similar. Autoradiographic studies confirmed the presence of both receptor subtypes on the ZG as well as on APA cells. Thus, the genes of ET-1 and both its receptor subtypes ETA and ETB are actively transcribed in the human adrenal cortex. Furthermore, both receptor subtypes are translated into proteins in ZG and APA cells.

Studies on the retina of the diabetic db/db mouse. I. Endothelial cell-pericyte ratio

The genetically diabetic db/db mouse is a model of type-2 diabetes, where nephropathy and neuropathy, but not retinopathy were observed. The authors studied the retinas (trypsin digestion technique) of 16 db/db mice and 16 age-matched litter mates (db/m; controls), divided into five age groups. They noted a marked increase in the ratio of endothelial cells to intramural pericytes in diabetic mice compared to controls. This increase resulted from a selective and highly significant loss of pericytes in db/db mice (p less than 0.05). Some strand-like and relatively acellular capillaries were also observed. The db/db mouse may represent an adequate model for studies on the pathogenesis of retinopathy.

Distribution and functional significance of angiotensin-II AT1- and AT2-receptor subtypes in the rat adrenal gland

The distribution and the functional significance of angiotensin-II (ANG-II) receptor subtypes, AT1 and AT2, in the rat adrenal gland has been investigated in vitro. Autoradiographic assessment of the selective displacement of [125I]ANG-II binding by selective ligands of the two receptor subtypes indicated that zona glomerulosa (ZG) was provided with both AT1 and AT2, and adrenal medulla (AM) almost exclusively with AT2 receptors. ANG-II (10(-9) M) evoked a marked rise in the secretion of aldosterone by dispersed ZG cells and catecholamines by AM fragments. The selective AT1-receptor antagonist DuP753 blocked aldosterone response to ANG-II, while the selective AT2-receptor antagonist PD123319 was ineffective. Catecholamine response to ANG-II was inhibited by PD123319 and only moderately affected by high concentrations of DuP753. The selective AT2-receptor agonist CGP42112 did not change basal aldosterone release of ZG cells, but concentration-dependently enhanced basal catecholamine release by AM fragments. In light of these findings the conclusion is drawn that in the rat the aldosterone secretagogue effect of ANG-II is exclusively mediated by the AT1 receptors present in the ZG, while the catecholamine secretagogue action preminently involves the activation of AT2 receptor located on medullary chromaffin cells.

Investigations on the morphology and function of adrenocortical tissue regenerated from gland capsular fragments autotransplanted in the musculus gracilis of the rat

This paper describes the function and morphology of regenerated adrenocortical nodules obtained by implanting, in the musculus gracilis of rats, several (n = 6-7) fragments of the capsular tissue of their excised adrenal glands. Four months after the operation, each bilaterally adrenalectomized rat developed six or seven well encapsulated adrenocortical nodules about 2-3 mm in diameter and always lacking chromaffin cells, and displayed almost complete normalization of basal and stimulated blood levels of corticosterone, but not of aldosterone. In vitro study showed that regenerated nodules were well functioning as far as glucocorticoid production was concerned. Accordingly, electron microscopy and stereology indicated that the majority of the parenchymal cells (independently of their location in the outer subcapsular, middle, or inner portions) closely resembled those of the zonae fasciculata/reticularis of the adrenal gland of age-matched sham-operated rats. By contrast, regenerated nodules evidenced a relative impairment in aldosterone secretion, and this was coupled with the presence of only a few zona glomerulosa-like cells. Such cells were grouped in small islets located near the few connective trabeculae detaching from the capsule, and autoradiography showed that they were the only parenchymal elements of the nodule able to bind [125I]angiotensin-II. The possibility is suggested that the paucity of zona glomerulosa-like cells in regenerated nodules could be ascribed to the absence of zona medullaris, which is currently thought to exert a paracrine control on the growth and secretion of zona glomerulosa in the rat adrenal glands.

The role of endothelins in the paracrine control of the secretion and growth of the adrenal cortex

Endothelins (ETs) are a family of vasoactive peptides (ET-1, ET-2, and ET-3) mainly secreted by vascular endothelium and widely distributed in the various body systems, where they play major autocrine/paracrine regulatory functions, acting via two subtypes of receptors (ETA and ETB): Adrenal cortex synthesizes and releases ETS and expresses both ETA and ETB. Zona glomerulosa possesses both ETA and ETB, whereas zona fasciculata/reticularis is almost exclusively provided with ETB. ETS exert a strong mineralocorticoid and a less intense glucocorticoid secretagogue action, mainly via ETB receptors. ETS also appear to enhance the growth and steroidogenic capacity of zona glomerulosa and to stimulate its proliferative activity. This trophic action of ETS is likely to be mediated mainly by ETA receptors. The intraadrenal release of ETS undergoes a multiple regulation, with the rise in blood flow rate and the local release of nitric oxide being the main stimulatory factors. Data are also available that indicate that ETS may also have a role in the pathophysiology of primary aldosteronism caused by adrenal adenomas and carcinomas.

Observation of tt[over ¯]H Production

The observation of Higgs boson production in association with a top quark-antiquark pair is reported, based on a combined analysis of proton-proton collision data at center-of-mass energies of sqrt[s]=7, 8, and 13 TeV, corresponding to integrated luminosities of up to 5.1, 19.7, and 35.9  fb^{-1}, respectively. The data were collected with the CMS detector at the CERN LHC. The results of statistically independent searches for Higgs bosons produced in conjunction with a top quark-antiquark pair and decaying to pairs of W bosons, Z bosons, photons, τ leptons, or bottom quark jets are combined to maximize sensitivity. An excess of events is observed, with a significance of 5.2 standard deviations, over the expectation from the background-only hypothesis. The corresponding expected significance from the standard model for a Higgs boson mass of 125.09 GeV is 4.2 standard deviations. The combined best fit signal strength normalized to the standard model prediction is 1.26_{-0.26}^{+0.31}.

Blockade of angiotensin II type 1 receptor and not of endothelin receptor prevents hypertension and cardiovascular disease in transgenic (mREN2)27 rats via adrenocortical steroid-independent mechanisms

We investigated the role of angiotensin II (Ang II) and endothelin-1 (ET-1) in transgenic (mREN2)27 rats, a model of the monogenic renin-dependent form of severe hypertension and cardiovascular disease. Four-week-old heterozygous male transgenic (mREN2)27 rats (n=24) were matched according to body weight (BW) and blood pressure (BP) and randomly allocated to receive a placebo (group P), the mixed endothelin type A and B receptor antagonist bosentan (100 mg/kg BW PO, group B), the Ang II type 1-specific receptor antagonist irbesartan (50 mg/kg BW PO, group I), or the endothelin type A-selective antagonist BMS-182874 (52 mg/kg BW PO, group BMS). After 4 weeks of treatment, during which BW and BP were measured weekly, animals were euthanized, and the heart, left ventricle, right ventricle, adrenal gland, brain, and kidney were weighed. The plasma levels of adrenocortical steroids were measured by high-performance liquid chromatography. The tension responses of ET-free segments of the thoracic aorta to 5 x 10(-6) mmol/L phenylephrine, 60 mmol/L KCl, and cumulative doses of ET-1 were assessed. The density of ET-1 receptor subtypes in the aorta and vascular structural changes in the mesenteric arterioles (100 to 200 microm ID) were also measured with autoradiography and myography, respectively. Compared with all other groups, group I rats showed significantly (P<0.001) lower systolic BP (group I, 161+/-8 mm Hg; group P, 269+/-23 mm Hg; group B, 275+/-17 mm Hg; and group BMS, 254+/-21 mm Hg), left ventricular weight (2.28+/-0.15 versus 3. 71+/-0.26, 3.38+/-0.27, and 3.96+/-0.51 mg/g BW, respectively), tension responses to vasoconstrictors, and normalized media thickness of the mesenteric arterioles (22.3+/-0.6 versus 25.3+/-0.5, 25.5+/-0.7, and 24.1+/-1.5 microm, respectively). Compared with levels in group P (78+/-25 pmol/mL), plasma aldosterone levels were significantly decreased in group B (51+/-11 pmol/mL) and group I (40+/-16 pmol/mL). Thus, endogenous ET-1 and Ang II contribute to the regulation of aldosterone, but only Ang II is crucial for the development of hypertension and related target organ damage via the Ang II type 1 receptor. Endogenous Ang II does not appear to enhance cardiovascular production of ET-1 in this model of hypertension within the time span of our experiment.

Observation of associated near-side and away-side long-range correlations in sqrt[s(NN)]=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δø) and pseudorapidity (Δη) are measured in sqrt[s(NN)] = 5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb(-1) of data as a function of transverse momentum (p(T)) and the transverse energy (ΣE(T)(Pb)) summed over 3.1 < η < 4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2 < |Δ η | < 5) "near-side" (Δø ~ 0) correlation that grows rapidly with increasing ΣE(T)(Pb). A long-range "away-side" (Δø ~ π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣE(T)(Pb), is found to match the near-side correlation in magnitude, shape (in Δη and Δø) and ΣE(T)(Pb) dependence. The resultant Δø correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δø modulation for all ΣE(T)(Pb) ranges and particle p(T).

Long-term stimulatory effect of neuropeptide-Y on the growth and steroidogenic capacity of rat adrenal zona glomerulosa

A prolonged infusion with neuropeptide-Y (NPY) caused a notable hypertrophy of the adrenal zona glomerulosa and its parenchymal cells in rats whose hypothalamo-hypophyseal axis and renin-angiotensin system were pharmacologically interrupted. Zona glomerulosa hypertrophy was associated with a significant rise in both basal and stimulated plasma levels of aldosterone. Zona fasciculata cells and the blood concentration of corticosterone were not affected. These findings suggest that NPY is specifically involved in the stimulation of the growth and steroidogenic capacity of rat adrenal zona glomerulosa.

Effects of pituitary adenylate-cyclase activating peptide (PACAP) on the rat adrenal secretory activity: preliminary in-vitro studies

PACAP did not affect secretory activity of dispersed rat adrenocortical cells, but it markedly raised aldosterone (ALDO) and corticosterone (B) production by adrenal slices, containing both medullary and cortical tissues. The secretagogue effects of PACAP were suppressed by PACAP(6-38), a specific competitive antagonist. Isoprenaline (IP) enhanced ALDO, but not B secretion of adrenal slices, and l-alprenolol (AL) completely blocked IP effect. AL and corticotropin-inhibiting peptide (CIP) partially reversed ALDO response to a maximal effective concentration of PACAP; AL did not affect B response to a maximal effective concentration of PACAP, while CIP completely annulled it. Quarters of regenerated adrenocortical autotransplants, that are completely deprived of chromaffin cells, though displaying ALDO and B responses to IP and ACTH, were insensitive to PACAP. The hypothesis is advanced that adrenal medulla plays a pivotal role in the mechanism(s) underlying the adrenocortical secretagogue action of PACAP, being mineralocorticoid and glucocorticoid responses probably mediated by the release by chromaffin cells of catecholamine and ACTH or exclusively ACTH, respectively.

Effects of substance P on the rat adrenal zona glomerulosa in vivo

Substance P (SP) acutely enhanced the plasma concentration of aldosterone in rats whose hypothalamo-hypophyseal-adrenal axis and renin-angiotensin system were pharmacologically interrupted. The maximal response was obtained with a dose of 100 micrograms/kg. A prolonged (7 days) subcutaneous infusion with SP (50 micrograms/kg/hr) caused a notable hypertrophy of zona glomerulosa cells associated with significant rises in both basal and angiotensin-stimulated plasma levels of aldosterone. Zona fasciculata and the blood concentration of corticosterone were not affected. These findings suggest that SP is specifically involved in the stimulation of the growth and secretory activity of the rat zona glomerulosa.

Observation of Bs(0)-Bs(0) oscillations

We report the observation of Bs(0)-Bs(0) oscillations from a time-dependent measurement of the Bs(0)-Bs(0) oscillation frequency Deltams. Using a data sample of 1 fb(-1) of pp collisions at square root of s=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, we find signals of 5600 fully reconstructed hadronic Bs decays, 3100 partially reconstructed hadronic Bs decays, and 61,500 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal for Bs(0)-Bs(0) oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10(-8), which exceeds 5sigma significance. We measure Deltams=17.77 +/- 0.10(stat) +/- 0.07(syst) ps(-1) and extract /V(td)/V(ts)/=0.2060+/-0.0007(Deltams)(-0.0060)(+0.008)(Deltamd+theor).

Observation of Higgs Boson Decay to Bottom Quarks

The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.3  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV, are described. When combined with previous VH measurements using data collected at sqrt[s]=7, 8, and 13 TeV, an excess of events is observed at m_{H}=125  GeV with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is 1.01±0.22. The combination of this result with searches by the CMS experiment for H→bb[over ¯] in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of 1.04±0.20.

The effects of ageing on the morphology and function of the zonae fasciculata and reticularis of the rat adrenal cortex

The morphological counterpart of the well-known age-dependent marked impairment of glucocorticoid secretion of rat adrenals was investigated by use of morphometric techniques. For this purpose 4-, 8-, 16- and 24-month-old rats were studied. Despite the notable lowering of both basal and ACTH-stimulated production of corticosterone by collagenase-dispersed inner adrenocortical cells, ACTH and corticosterone plasma concentrations displayed significant increases with ageing. Zona fasciculata (ZF) and zona reticularis (ZR) showed a notable hypertrophy in aged rats, which was due to rises in both the average volume and number of their parenchymal cells. The hypertrophy of ZF and ZR cells was in turn associated with increase in the volume of the mitochondrial compartment and proliferation of smooth endoplasmic reticulum, i.e., the two organelles involved in steroid-hormone synthesis. All these morphologic changes, conceivably due to the chronic exposure to high levels of circulating ACTH, are interpreted as a response enabling ZF and ZR to compensate for their age-dependent lowering in glucocorticoid secretion. Stereology also demonstrated that ZF and ZR cells underwent a striking age-related lipid-droplet repletion. Lipid droplets are the intracellular stores of cholesterol esters, the obligate precursors of steroid hormones in rats. This finding is in keeping with the contention that the mechanism underlying the age-dependent decline in rat-adrenal glucocorticoid secretion mainly involves impairments of the utilization of intracellular cholesterol previous to its intramitochondrial transformation to pregnenolone.

Ticlopidine prevents renal disease progression in rats with reduced renal mass

Functional and morphological studies were done in three groups of male Sprague-Dawley rats after removal of the right kidney and infarction of approximately five-sixths of the left. Group 1 received no specific therapy. Group 2 was treated with ticlopidine, 150 mg/kg per os, for 50 days starting 10 days after surgical ablation. Group 3 was given the thromboxane antagonist, GR 32191, 3 mg/kg b.i.d. orally for 50 days, like ticlopidine. Untreated Group 1 rats developed renal insufficiency, systemic hypertension, progressive proteinuria and glomerulosclerosis. In Group 2 treatment with ticlopidine was associated with less severe impairment of renal function. Proteinuria was significantly lower and animals were partially protected from the development of glomerulosclerosis. These animals had significantly prolonged skin bleeding time. In vitro ADP and arachidonic acid (AA)-induced platelet aggregation was inhibited. Systemic blood pressure was significantly lower than in controls. In Group 3 rats GR 32191 failed to influence progressive proteinuria and severity of glomerulosclerosis which were comparable to those in Group 1. Bleeding time was not prolonged, and in vitro platelet aggregation was inhibited only when AA was used as aggregating agent. Systemic blood pressure was not influenced. These studies suggest that a drug like ticlopidine, which has a broad spectrum of pharmacological actions on platelets and platelet-cell interactions, does retard the development of progressive renal injury when nephron number is reduced. Specific blocking of thromboxane A2 (TxA2) biological activity does not influence progressive renal disease in rats with remnant kidney.

Tachyzoite calcium changes during cell invasion by Toxoplasma gondii

The invasion of host cells by the obligate intracellular protozoan parasite Toxoplasma gondii is calcium dependent. We have identified two calcium storage areas in tachyzoites, the endoplasmic reticulum and vesicles that contain high concentrations of calcium as amorphous calcium phosphate precipitates. Our data indicate that these vesicles slowly lose their calcium during the intracellular development of the tachyzoite as their nucleus phosphorus content increases. We found fluctuations in the sulfur content of the tachyzoite during invasion following the exocytosis of protein from the secretory organelles, with a loss of sodium and chlorine, and the uptake of potassium from the host cell cytoplasm. We demonstrated that penetration of the tachyzoite into the host cell was accompanied by increases in the concentrations of phosphorus and sulfur in the host cell nucleus, probably due to increased transcription. The cytosol sodium concentrations decreased, while the potassium content increased. Thus, the subcellular element distribution of tachyzoites and host cells changes during invasion and intracellular growth of the parasites. In addition, our results indicate that tachyzoite calcium might be involved in the egress of the parasite from the host cell.

First flavor-tagged determination of bounds on mixing-induced CP violation in Bs0 --> J/psiphi decays

This Letter describes the first determination of bounds on the CP-violation parameter 2beta(s) using B(s)(0) decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2000 B(s)(0)-->J/psiphi decays reconstructed in a 1.35 fb(-1) data sample collected with the CDF II detector using pp collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2beta(s) and the decay-width difference DeltaGamma. Assuming the standard model predictions of 2beta(s) and DeltaGamma, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.

Search for magnetic monopoles in sqrt[s]=7 TeV pp collisions with the ATLAS detector

This Letter presents a search for magnetic monopoles with the ATLAS detector at the CERN Large Hadron Collider using an integrated luminosity of 2.0  fb(-1) of pp collisions recorded at a center-of-mass energy of sqrt[s]=7  TeV. No event is found in the signal region, leading to an upper limit on the production cross section at 95% confidence level of 1.6/ϵ  fb for Dirac magnetic monopoles with the minimum unit magnetic charge and with mass between 200 GeV and 1500 GeV, where ϵ is the monopole reconstruction efficiency. The efficiency ϵ is high and uniform in the fiducial region given by pseudorapidity |η|<1.37 and transverse kinetic energy 600-700<E(kin)sinθ<1400  GeV. The minimum value of 700 GeV is for monopoles of mass 200 GeV, whereas the minimum value of 600 GeV is applicable for higher mass monopoles. Therefore, the upper limit on the production cross section at 95% confidence level is 2 fb in this fiducial region. Assuming the kinematic distributions from Drell-Yan pair production of spin-1/2 Dirac magnetic monopoles, the efficiency is in the range 1%-10%, leading to an upper limit on the cross section at 95% confidence level that varies from 145 fb to 16 fb for monopoles with mass between 200 GeV and 1200 GeV. This limit is weaker than the fiducial limit because most of these monopoles lie outside the fiducial region.

Adrenal medulla is involved in the aldosterone secretagogue effect of substance P

Substance P (SP) increased aldosterone secretion of rat adrenal slices, but not of isolated zona glomerulosa cells, and this effect was annulled by two specific antagonist of SP (SP-A). Both tissue preparations displayed an aldosterone secretory response to isoprenaline (IP) that was blocked by l-alprenolol (AL). AL reversed the aldosterone response of adrenal slices to IP, SP, or IP plus SP, whereas SP-A only suppressed that to SP. Quarters of adrenocortical autotransplants, which are completely deprived of chromaffin cells, showed an aldosterone response to IP, but not to SP. These findings suggest that the mechanism underlying the aldosterone secretagogue action of SP probably involves the stimulation of catecholamine release by adrenal medulla chromaffin cells.

Distribution and functional significance of the endothelin receptor subtypes in the rat adrenal gland

Endothelins (ET) are a family of vasoactive peptides that act via two subtypes of receptors, named ETA and ETB. ET-1 binds to both ETA and ETB, whereas the isopeptide ET-3 preferentially binds to ETB. The localization of ETA and ETB receptors in the rat adrenal gland and their involvement in the adrenal secretagogue effect of ETs has been studied in vitro. Autoradiographic assessment of the selective displacement of [125I]ET-1, [125I]ET-3 and [125I]BQ-3020 (an ETB agonist) by BQ-123 or BQ-788 (specific antagonists of ETA and ETB, respectively) indicates that the zona glomerulosa and adrenal medulla possess both ETA and ETB, whereas the zona fasciculata/reticularis is exclusively provided with ETB. ET-1, ET-3 and BQ-3020 enhance aldosterone and corticosterone secretion by dispersed cells of the zona glomerulosa and zona fasciculata/reticularis, respectively. BQ-123 does not affect the secretagogue action of these three agonists, whereas BQ-788 completely annuls it. ET-1 induces a marked rise in catecholamine release by fragments of the adrenal medulla, and both BQ-123 and BQ-788 partially reverse this effect. ET-3 and BQ-3020 elicit a catecholamine release that is less intense than that produced by ET-1; this response is unaffected by BQ-123 and abolished by BQ-788. Thus, in the rat, the corticosteroid secretagogue effect of ETs seems to be exclusively mediated by the ETB receptor subtype, and the catecholamine secretagogue action by both ETA and ETB. The functional relevance of ETA receptors present in the zona glomerulosa remains to be investigated.

Proadrenomedullin N-terminal 20 peptide (PAMP), acting through PAMP(12-20)-sensitive receptors, inhibits Ca2+-dependent, agonist-stimulated secretion of human adrenal glands

Proadrenomedullin N-terminal 20 peptide (PAMP) is a 20-amino acid hypotensive peptide expressed in the adrenal medulla. We investigated the localization and function of PAMP receptors in the human adrenal gland. Autoradiography showed the presence of [125I]PAMP-binding sites in both zona glomerulosa and adrenal medulla that were displaced by cold PAMP and PAMP(12-20) but not by other preproadrenomedullin-derived peptides. PAMP, but not PAMP(12-20), counteracted, in a concentration dependent manner, both aldosterone response of zona glomerulosa cells and catecholamine response of adrenal medulla cells to BAYK-8644, the selective agonist of voltage-activated Ca2+ channels, as well as to K+ and angiotensin II. PAMP(12-20) partially reversed this antisecretagogue effect of PAMP. Collectively, these findings suggest (1) that PAMP inhibits Ca2+-dependent, agonist-stimulated aldosterone and catecholamine secretion, acting via specific receptors and through a mechanism involving the impairment of Ca2+ influx; and (2) that PAMP(12-20) acts as a weak antagonist of PAMP receptors, thereby suggesting that both C- and N-terminal sequences of the PAMP molecule are required for this peptide to exert its antisecretagogue action on the human adrenal gland.