Human relaxin-2 (hereafter simply defined as "relaxin") is a 6-kDa peptidic hormone best known for the physiological role played during pregnancy in the growth and differentiation of the reproductive tract and in the renal and systemic hemodynamic changes. This factor can also be involved in the pathophysiology of arterial hypertension and heart failure, in the molecular pathways of fibrosis and cancer, and in angiogenesis and bone remodeling. It belongs to the relaxin peptide family, whose members comprehensively exert numerous effects through interaction with different types of receptors, classified as relaxin family peptide (RXFP) receptors (RXFP1, RXFP2, RXFP3, RXFP4). Research looks toward the in-depth examination and complete understanding of relaxin in its various pleiotropic actions. The intent is to evaluate the likelihood of employing this substance for therapeutic purposes, for instance in diseases where a deficit could be part of the underlying pathophysiological mechanisms, also avoiding any adverse effect. Relaxin is already being considered as a promising drug, especially in acute heart failure. A careful study of the different RXFPs and their receptors and the comprehension of all biological activities of these hormones will probably provide new drugs with a potential wide range of therapeutic applications in the near future.

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http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120578/-/DC1.

Background/Aims: To evaluate the balance between arginine-vasopressin (AVP) and apelin during hemodialysis and its role in hypotension onset and in the inflammation status. Methods: We enrolled 50 patients chronically treated with hemodialysis. We assessed plasmatic osmolality, AVP, apelin, mean blood pressure (BP), high-sensitivity C-reactive protein (hsCRP) and β₂-microglobulin. Results: Apelin rises during dialytic treatment (from 0.68 ± 0.34 to 1.89 ± 0.56 pg/ml, p < 0.0001), while plasmatic osmolality (from 325 ± 4.54 to 311 ± 1.20 mosm/kg H₂O, p < 0.0001), AVP (from 4.28 ± 1.12 to 2.48 ± 0.50 pg/ml, p < 0.0001) and mean BP (from 124 ± 6 to 110 ± 7 mm Hg, p < 0.0001) decrease. At multivariate regression with respect to apelin, only mean BP remains (r = –0.95, p < 0.0001). We also correlated the AVP/apelin ratio with BP. Moreover, apelin is inversely related to hsCRP (r = –0.79, p < 0.0001). Conclusions: The AVP/apelin balance changes with plasmatic osmolality variations induced by hemodialytic sessions and could represent a physiopathological marker of arterial hypo- and hypertension. Finally, apelin appears inversely related to inflammation markers.

The synthesis of recombinant human erythropoietin has marked a turning point in the treatment of anaemia secondary to chronic kidney disease. However, the potentially fatal cardio- and cerebrovascular complications of the intake of high-doses of ESAs (erythropoiesis-stimulating agents), such as those observed in athletes who resort to doping, reason out the ever-prevalent debate concerning the balance between the risks and benefits of ESA administration for therapeutic purposes. Hence, there is still a discussion as to what values haemoglobin should ideally be maintained at. Additional concerns arise in cancer patients due to the ability of erythropoietin to act as an angiogenic and, in general, as a cell growth factor, because this might favour the progression of neoplastic disease. We summarized the prominent points of the latest guidelines on the management of anaemia in nephropathic patients, also identifying the possible risks that may result from the tendency to aim at too low haemoglobin levels.