Search

An abnormal activation state of polymorphonuclear leukocytes (PMN) plays a key role in organ injury induced by vascular atherosclerotic disease (VAD) and diabetes mellitus (DM). PMN membrane fluidity and cytosolic Ca2+ content can be considered markers of PMN activation. In this research we evaluated the PMN membrane fluidity and cytosolic Ca2+ content in VAD subjects with and without type 2 DM and examined the association between these parameters and the mono- or polyvascular localization. We enrolled 155 VAD subjects, including 92 non-diabetic (group A: mean age 63.6 +/- 9.2 years) and 63 diabetic patients (group B: mean age 65.4 +/- 7.8 years). Among group A 63 patients had monovascular and 29 polyvascular disease; among group B 30 patients had monovascular and 22 polyvascular disease. In each patient we evaluated the PMN membrane fluidity labelling the cells with the fluorescent probe 1,4-(trimethylamino)-phenyl-4-phenylhexatriene (TMA-DPH) and the PMN cytosolic Ca2+ content marking the cells with the fluorescent probe Fura 2-AM. PMN membrane fluidity did not discriminate normal subjects from diabetic and non-diabetic VAD subjects, while cytosolic Ca2+ content was increased in both groups. PMN membrane fluidity did not distinguish normal subjects from mono- or polyvascular VAD patients with and without type 2 DM. PMN cytosolic Ca2+ content was increased especially in monovascular VAD patients; both mono- and polyvascular VAD subjects with DM had a PMN cytosolic Ca2+ content higher than normals. Our results show the presence of an increased PMN cytosolic Ca2+ content in diabetic and non-diabetic VAD subjects but no association was observed between this increase and the mono- or polyvascular localization.

Acute myocardial infarction (AMI) is associated with an elevated polymorphonuclear leukocyte (PMN) count and a PMN rheological impairment. In this study we evaluated two major rheological aspects (membrane fluidity and cytosolic Ca2+ concentration) in a group of young adults with AMI. We enrolled 41 AMI patients (39 men and 2 women; mean age 41.0 +/- 4.0 years), who were examined 5-10 days after AMI (T1) and 12 months later (T2). The membrane fluidity was obtained labelling granulocytes with the fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) and considering the degree of fluorescence polarization, inversely correlated to the membrane lipid fluidity. The cytosolic Ca2+ content was obtained marking PMN cells with the fluorescent probe Fura-2AM and considering the ratio between the Fura 2-Ca2+ complex and the unchelated Fura 2 fluorescence intensity. Both parameters were evaluated at baseline and after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) at the concentration of 4.5 muM, prolonged for 5 and 15 minutes. At T1 the PMN membrane fluidity and cytosolic Ca2+ content in AMI patients were respectively decreased and increased in comparison with control group. At T2 the membrane fluidity was not any more different from control subjects, but there was also a further increase in cytosolic Ca2+ content. In vitro, PMN activation caused no significant variation of these parameters in the control group, while in AMI patients membrane fluidity significantly decreased and cytosolic Ca2+ content increased not only during the initial stage, but also after 12 months. The long-term functional alteration of PMN cells observed in young adults with AMI confirms the role of these cells in the inflammatory response following AMI. In the light of these data, the use of molecules able to modulate granulocyte activity, such as calcium channel blockers or pentoxifylline, should be reconsidered in myocardial infarction, together with the usual pharmacological treatment.

Abstract: The aim of this study is to investigate the effects in vitro induced by androgenic anabolic steroids (AAS) (testosterone, nandrolone, androstenedione, norandrostenedione, and norandrostenediol) used illicitly in sport competitions, on the proliferation ability, apoptosis and the intracellular calcium concentration ([Ca2+]i) in human umbilical vein endothelial cells (HUVECs), selected as a prototype of a biological target system whose structure and function can be affected by steroids. For this purpose, we evaluated the proliferation inhibition by cytotoxic assay expressed as the concentration of drug inducing a 50% decrease in growth (IC50). The IC50 was reached for testosterone at 100μM, androstenedione at 375μM, nandrolone at 9μM, norandrostenedione at 500μM. The IC50 value for norandrostenediol was not reached until a concentration of 6000μM. The apoptotic effect was evaluated by flow cytometry at IC50 for each drug. We observed that testosterone induced 31% of apoptotic cells, norandrostenedione 25%, androstenedione 15% and nandrolone 18%. We have analyzed the effects of these drugs on [Ca2+]i both in the immediate and long-term continuous presence of each compound. Our data show a statistically significant increase of [Ca2+]i in the acute condition and in long-term treated cultures, suggesting that androgen steroids modulate intracellular levels of calcium independent of incubation time or compound identity. As a whole, this study demonstrates that AAS might alter endothelial homeostasis, predisposing to the early endothelial cell activation that is responsible for vascular complications observed frequently in AAS users. [Copyright &y& Elsevier]