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Tetrahydrobiopterin (BH4) reverses established heart failure normalizing calcium cycling at the cardiomyocytes level
No full textAutoradiographic evidence that zona glomerulosa and capsular vessels of the human adrenal cortex are provided with different subtypes of adrenomedullin receptors
No full textFrozen sections of normal adrenal glands, obtained from patients undergoing unilateral nephrectomy for kidney cancer, were labeled in vitro with human [125I]ADM(1-52). Autoradiography and quantitative densitometry showed the presence of abundant ADM(1-52) binding sites in both zona glomerulosa (ZG) and capsular vessels, which were displaced with about the same efficiency by cold ADM(1-52) and rat ADM(1-50). The selective calcitonin gene-related peptide type 1 (CGRPI) ligand CGRP(8-37) eliminated, although less efficiently than ADMs, [125I]ADM(1-52) binding in the ZG, but not in the capsular vessels. These findings suggest the existence of different receptor subtypes for ADM in the human adrenal cortex. The CGRP(8-37)-sensitive receptors located in the ZG may mediate the well-known inhibitory effect of ADM on aldosterone secretion, while the CGRP(8-37)-insensitive receptors present in the capsular vessel may be involved in the ADM-induced rise in adrenal blood flow
Adrenomedullin (ADM) and PAMP inhibit the aldosterone response of normal human adrenocortical (NHAC) and Conn's adenoma (CA) cells to angiotensin-II.
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Proadrenomedullin N-terminal 20 peptide (PAMP), acting through PAMP(12–20)-sensitive receptors, inhibits Ca2+-dependent, agonist-stimulated secretion of human adrenal glands.
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Distribution, functional role, and signaling mechanism of adrenomedullin receptors in the rat adrenal gland
No full textAdrenomedullin (ADM) is a hypotensive peptide, highly expressed in the mammalian adrenal medulla, which belongs to a peptide
superfamily including calcitonin gene-related peptide (CGRP) and amylin. Quantitative autoradiography demonstrated the presence of
abundant [125I]ADM binding sites in both zona glomerulosa (ZG) and adrenal medulla. ADM binding was selectively displaced by
ADM(22–52), a putative ADM-receptor antagonist, and CGRP(8–37), a ligand that preferentially antagonizes the CGRP1-receptor subtype.
ADM concentration-dependently inhibited K1-induced aldosterone secretion of dispersed rat ZG cells, without affecting basal hormone
production. Both ADM(22–52) and CGRP(8–37) reversed the ADM effect in a concentration-dependent manner. ADM counteracted the
aldosterone secretagogue action of the voltage-gated Ca21-channel activator BAYK-8644, and blocked K1- and BAYK-8644-evoked rise
in the intracellular Ca21 concentration of dispersed ZG cells. ADM concentration-dependently raised basal catecholamine (epinephrine and
norepinephrine) release by rat adrenomedullary fragments, and again the response was blocked by both ADM(22–52) and CGRP(8–37).
ADM increased cyclic-AMP release by adrenal-medulla fragments, but not capsule-ZG preparations, and the catecholamine response to
ADM was abolished by the PKA inhibitor H-89. Collectively, the present findings allow us to draw the following conclusions: (1) ADM
modulates rat adrenal secretion, acting through ADM(22–52)-sensitive CGRP1 receptors, which are coupled with different signaling
mechanisms in the cortex and medulla; (2) ADM selectively inhibits agonist-stimulated aldosterone secretion, through a mechanism
probably involving the blockade of the Ca21 channel-mediated Ca21 influx; (3) ADM raises catecholamine secretion, through the activation
of the adenylate cyclase/PKA signaling pathway
Inhibitory effect of adrenomedullin (ADM) on the aldosterone response or normal human adrenocortical (NHAC) and Conn's adenoma (CA) cells to angiotensin-IL
No full textHuman adrenomedullin (ADM) is a 52-amino acid hypotensive peptide, which possesses a disulfide bridge-formed six-membered ring in 16-21 position. The ring structure, and both the N- and C-terminal amino-acid sequences seem to play a key role in the vascular effects of ADM(1-52), and we have investigated whether the same is true for the inhibitory effect of this peptide on the aldosterone response of zona glomerulosa (ZG) cells to angiotensin-II (ANG-II). Autoradiography showed the presence of abundant [125I]ADM(1-52) binding sites in the ZG of human adrenals, which were displaced not only by cold ADM(1-52), but also by both ADM(13-52) and ADM(22-52); ADM fragments 1-12, 15-22 and 16-31 were ineffective. ADM(1-52) and ADM(13-52), but not other fragments, concentration-dependently inhibited ANG-II-stimulated aldosterone secretion of dispersed human adrenocortical cells. The aldosterone antisecretagogue actions of ADM(1-52) and ADM(13-52) were counteracted by ADM(22-52) in a concentration-dependent manner, while other ADM fragments were ineffective. In light of these findings the following conclusions could be drawn: (i) human ZG cells are provided with ADM(22-52)-sensitive receptors; (ii) the six-membered ring structure and the C-terminal, but not N-terminal, amino-acid sequence are both essential for ADM(1-52) to exert its antimineralocorticoid action; and probably (iii) the C-terminal sequence is needed for ADM(1-52) to bind its ZG receptors, while the ring structure is required for the receptor activation
Inhibitory effect of adrenomedullin (ADM) on the aldosterone response of human adrenocortical cells to angiotensin-II: role of ADM(22-52)-sensitive receptors.
No full textimpact factor 2001=1.75
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