Activation of NADPH oxidase and superoxide anion release in human neutrophils has been shown to be dependent on Na+/H+ exchange, and inhibition of intracellular alkalinisation has been proposed as a mechanism of action for some anti-inflammatory drugs. The effect of nimesulide, a novel nonsteroidal anti-inflammatory drug, on intracellular pH (pHi) regulation by the Na+/H+ antiport in human neutrophils was examined using the pH-sensitive fluorescent probe 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF), When stimulated by formylmethionylleucyl-phenylalanine (fMLP) or phorbol-12-myristate-13-acetate (PM A), neutrophils displayed changes in pHi consisting of an initial acidification followed by a sustained alkalinising phase indicative of antiport activation. Nimesulide did not change the pHi of resting neutrophils and did not affect the pHi response to stimulation, It is concluded that the anti-inflammatory effect of nimesulide is not directly linked to interactions with the Na+/H+ antiport or other pathways affecting the regulation of pHi.

Background: Diabetic dyslipidemia. is characterized by greater triglyceridation of all lipoproteins and low levels of plasma high-density lipoprotein cholesterol (HDL-C). In this condition, the serum level of low-density lipoprotein cholesterol (LDL-C) is only slightly elevated. The central role of decreased serum HDL-C level in diabetic cardiovascular disease has prompted the establishment of a target of greater than or equal to50 mg/dL in patients with diabetes mellitus (DM).Objective: The aim of the study was to assess the effects of once-daily administration of fluvastatin extended release (XL) 80 mg or atorvastatin 20 mg on serum HDL-C levels in patients with type 2 DM and low levels of serum HDL-C.Methods: This 4-month, prospective, open-label, randomized, blinded-end point (PROBE) trial was conducted at Endocrinology and Diabetology Service, L. Sacco-Polo University Hospital (Milan, Italy). Patients aged 45 to 71 years with type 2 DM receiving standard oral antidiabetic therapy, with serum HDL-C levels <50 mg/dL, and with moderately high serum levels of LDL-C and triglycerides (TG) were enrolled. After 1 month of lifestyle modification and dietary intervention, patients who were still showing a decreased HDL-C level were randomized, using a 1:1 ratio, to receive fluvastatin XL 80-mg tablets or atorvastatin 20-mg tablets, for 3 months. Lipoprotein metabolism was assessed by measuring serum levels of LDL-C, HDL-C, TG, apolipoprotein (apo) A-I (the lipoprotein that carries HDL), and apo B (the lipoprotein that binds very low-density lipoprotein cholesterol, intermediate-density lipoprotein, and LDL on a molar basis). Patients were assessed every 2 weeks for treatment compliance and subjective adverse events. Serum creatine phosphokinase and liver enzymes were assessed before the run-in period, at the start of the trial, and at 1 and 3 months during the study.Results: One hundred patients were enrolled (50 patients per treatment group; fluvastatin XL group: 33 men, 17 women; mean [SD] age, 58 [12] years; atorvastatin group: 39 men, 11 women; mean [SD] age, 59 [11] years). In the fluvastatin group after 3 months of treatment, mean (SD) LDL-C decreased from 149 (33) to 95 (25) mg/dL (36%; P<0.01), TG decreased from 437 (287) to 261 (164) mg/dL (40%; P<0.01), and HDL-C increased from 41 (7) to 46 (10) mg/dL (12%; P<0.05). In addition, apo A-I increased from 118 (18) to 124 (15) mg/dL (5%; P<0.05) and apo B decreased from 139 (27) to 97 (19) mg/dL (30%; P<0.05). In the atorvastatin group, LDL-C decreased from 141 (25) to 84 (23) mg/dL (40%; P<0.01) and TG decreased from 411 (271) to 221 (87) mg/dL (46%; P<0.01). Neither HDL-C (41 [7] vs 40 [6] mg/dL; 2%) nor apo A-I (117 [19] vs; 114 [19] mg/dL; 3%) changed significantly. However, apo B decreased significantly, from 131 (20) to 92 (17) mg/dL (30%; P<0.05). Mean changes in HDL-C (+5 [8] vs -1 [2] mg/dL; P<0.01) and apo A-I (+6 [18] mg/dL vs -3 [21] mg/dL; P<0.01) were significantly greater in the fluvastatin group than in the atorvastatin group, respectively. However, the decreases in LDL-C (54 [31] vs 57 [32] mg/dL), TG (177 [219] vs 190 [65] mg/dL), and apo B (42 [26] vs 39 [14] mg/dL) were not significantly different between the fluvastatin and atorvastatin groups, respectively. No severe adverse events were reported.Conclusions: Fluvastatin XL 80 mg and atorvastatin 20 mg achieved mean serum LDL-C (less than or equal to100 mg/dL) and apo B target levels (less than or equal to100 mg/dL) in the majority of this population of patients with type 2 DM, but mean serum HDL-C level was increased significantly only with fluvastatin-16 patients (32%) in the fluvastatin group compared with none in the atorvastatin group achieved HDL-C levels greater than or equal to50 mg/dL. The increase in HDL-C in the fluvastatin-treated patients was associated with an increase in apo A-I, suggesting a potential pleiotropic and selective effect in patients with low HDL-C levels. Copyright (C) 2004 Excerpta Medica, Inc.

Central nervous system feedback loops centered on hypothalamic neurons control atrial natriuretic peptide (ANP). We evaluated the ANP response to arterial hypotension, isotonic blood volume expansion, and increase in plasma osmolality in 14 patients with multiple system atrophy (MSA). Seven of the patients were characterized by a lack of vasopressin response to hypotension (MSA type B), suggesting chronic sinoaortic denervation, and seven by a preserved response (MSA type A). Orthostatic hypotension decreased ANP in controls and type A patients, whereas ANP in type B was not affected. Isotonic saline infusion increased ANP and diuresis in controls and type A patients, whereas it did not affect ANP in type B. Osmotic load increased plasma osmolality and vasopressin in controls and MSA patients and ANP in controls and type A but not in type B patients. In MSA patients with altered afferent control of vasopressin, ANP secretion is not stimulated by blood volume expansion, osmotic load, or blood pressure, suggesting that afferent excitatory control plays a role in the release of ANP.

Furlan, Raffaello; Piazza, Simona; Grittini, Alessandra; Crema, Cristina; Chebat, Enrica; Bevilacqua, Maurizio; Porta, Alberto; Baselli, Giuseppe; Lombardi, Federico; Malliani, Alberto Author Information

Turiel, M.; Frisinghelli, A.; Crema, C.; Chebat, E.; Bevilacqua, M.; Norbiato, R. Author Information

This study concerns 9 iv drug abusers with acquired immunodeficiency syndrome (AIDS) who developed hypercortisolism without the clinical signs or metabolic consequences of hypercortisolism. All patients were characterized by an Addisonian picture (weakness, weight loss, hypotension, hyponatremia, and intense mucocutaneous melanosis). An acquired form of peripheral resistance to glucocorticoids was suspected. We, therefore, examined glucocorticoid receptor characteristics on mononuclear leukocytes by measuring [3H]dexamethasone binding and the effect of dexamethasone on [3H]thymidine incorporation, which is one of the effects of glucocorticoid receptor activation. Glucocorticoid receptor density was increased in AIDS patients with an Addisonian picture (group 1; 16.2 +/- 9.4 fmol/million cells) compared to values in 12 AIDS patients without an Addisonian picture (group 2; 6.05 +/- 2.6 fmol/million cells; P less than 0.01) and sex- and age-matched controls (3.15 +/- 2.3 fmol/million cells; P less than 0.01). The affinity of glucocorticoid receptors (Kd) was strikingly decreased (9.36 +/- 3.44 nM in group 1; 3.2 +/- 1.5 nM in group 2; 2.0 +/- 0.8 nM in controls; P less than 0.01). [3H]Thymidine incorporation was decreased dose-dependently by dexamethasone in controls and patients; the effect was significantly blunted (P less than 0.05) in group 1 patients, which suggests that activation of glucocorticoid receptor is impaired as a result of the glucocorticoid receptor abnormality. In conclusion, AIDS patients with hypercortisolism and clinical features of peripheral resistance to glucocorticoids are characterized by abnormal glucocorticoid receptors on lymphocytes. Resistance to glucocorticoids implies a complex change in immune-endocrine function, which may be important in the course of immunodeficiency syndrome.

1. Angiotensin converting enzyme (ACE), a dipeptidyl carboxypeptidase which catalyzes the final activation step in the formation of angiotensin II, was identified by radioligand studies in rat heart and lung. In this work we identified ACE binding sites in human left ventricle and lung by radioligand binding using the ACE inhibitor [3H]-ramiprilat in all tissues tested was saturable, temperature and zinc-dependent, and inhibited by EDTA. In human left ventricle homogenate we found a density of binding sites of 121 +/- 15 fmol mg-1 protein (n = 4) with an affinity (Kd) of 850 +/- 55 pM, whereas in rat left ventricle the same values were 23 +/- 4 fmol mg-1 protein and 315 +/- 30 pM, (n = 4), respectively. 3. [3H]-ramiprilat binding to rat (n = 4) and human lung (n = 4) showed a binding site density of 2132 +/- 155 and 1085 +/- 51 fmol mg-1 protein respectively with an affinity of 639 +/- 54 and 325 +/- 22 pM. The lung:heart ratio of ACE binding site density was about 9:1 in man and 100:1 in rat. 4. The binding affinities of 13 ACE inhibitors were evaluated on human heart and lung: the drugs tested showed a wide range of affinities for the ACE binding sites in both tissues, and the affinity for lung was significantly greater than for heart for most of the drugs. 5. The greater potency of some ACE inhibitors in displacing [3H]-ramiprilat in human lung compared with the heart indicates differences between ACE binding sites in these tissues and suggests the possibility of a selective organ-targeted therapeutic approach.

Multiple system atrophy (MSA) is a heterogeneous group of central neurological degenerations often associated with diffuse deterioration of the hypothalamic cholinergic neurons. In the hypothesis of an altered cholinergic regulation of vasopressin release, we evaluated vasopressin response to metoclopramide (20 mg i.v.), a cholinomimetic agonist, in 12 MSA patients. In the same patients the hemodynamic and osmolal control of vasopressin was also evaluated. We found that MSA patients had significantly lower basal plasma vasopressin values and higher plasma osmolality than control subjects. However, they displayed a normal vasopressin response to osmotic stimulation. During head-up tilting, orthostatic hypotension occurred in all patients, and the vasopressin response to hypotension was severely blunted in 5 of 12 patients, thus demonstrating the presence of a lesion of the afferent noradrenergic pathways.Metoclopramide increased vasopressin in control subjects, whereas MSA patients did not display any increase in vasopressin. These results clearly indicate that cholinergic neurons that regulate vasopressin release are damaged in MSA. Such an alteration may be dissociated from the lesion of the afferent noradrenergic pathways. As a consequence of the altered vasopressin release, MSA patients show lower plasma vasopressin levels with consequent propensity to dehydration and hypovolemia, which may further aggravate their hypotension.

Bevilacqua, M.; Vago, T.; Bertora, P.; Baldi, G.; Chebat, E.; Norbiato, G. Author Information

Activation of NADPH oxidase and Superoxide anion release in human neutrophils has been shown to be dependent on Na+/H+ exchange, and inhibition of intracellular alkalinisation has been proposed as a mechanism of action for some anti-inflammatory drugs. The effect of nimesulide, a novel nonsteroidal anti-inflammatory drug, on intracellular pH (pHi) regulation by the Na+/H+ antiport in human neutrophils was examined using the pH-sensitive fluorescent probe 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF). When stimulated by formylmethionylleucyl-phenylalanine (fMLP) or phorbol-12-myristate-13-acetate (PMA), neutrophils displayed changes in pHi consisting of an initial acidification followed by a sustained alkalinising phase indicative of antiport activation. Nimesulide did not change the pHi of resting neutrophils and did not affect the pHi response to stimulation. It is concluded that the anti-inflammatory effect of nimesulide is not directly linked to interactions with the Na+/H+ antiport or other pathways affecting the regulation of pHi.

β2-Adrenergic agonists inhibit the generation of Superoxide anions by neutrophils through action at β2-adrenoceptors. The aim of this study was to examine the characteristics of neutrophil β2-adrenoceptors after the activation of the respiratory burst by phorbol 12-myristate 13-acetate (PMA), which stimulates protein kinase C (PKC), and by drugs that are PKC antagonists. Binding of the hydrophilic adrenergic antagonist [3H]-(−)-CGP 12177 was rapid, reversible, of high affinity (Kd = 81 ± 12 pmol/L), stereospecific, of the β2 subtype and saturable, demonstrating a receptor density of 1.9 ± 0.1 fmol/million cells.

The effects of a cable car trip from 1370 m (4500 ft) to 3460 m (11350 ft) were studied in 6 lowlanders (3 men and 3 women, mean age 31 +/- 4 years, living at an altitude of less than 500 m) and in 10 highlanders (all males, mean age 37 +/- 12 years, ski teachers and cable car workers working for greater than or equal to 6 months/year at a greater than 3000 m). Cuff blood pressure (BP), heart rate, plasma catecholamines, serum renin, aldosterone, ACTH and cortisol were measured immediately before and 20 min after the trip, at rest and at the same air temperature. A handgrip test was also performed under the same conditions. At baseline, lowlanders and highlanders showed significant differences in diastolic BP (86 +/- 5 mmHg in lowlanders and 91 +/- 4 mmHg in highlanders, p = 0.05), plasma noradrenaline (323 +/- 114 pg/ml in lowlanders and 585 +/- 255 in highlanders, p less than 0.05), serum renin (10 +/- 6 pg/ml in lowlanders and 17 +/- 8 in highlanders, p less than 0.05), and serum cortisol (163 +/- 54 ng/ml in lowlanders and 120 +/- 25 in highlanders, p less than 0.01). The acute exposure to high altitude did not modify BP, heart rate or any of the measured cardiovascular hormones in either group. The handgrip test provoked a significant increase in systolic and diastolic BP in both lowlanders and highlanders (p less than 0.01), and this response was not modified by the change in altitude; however, highlanders showed significantly smaller increases in systolic BP than lowlanders at both altitudes (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Catecholamines are involved critically in the mechanisms of liver cell proliferation by acting on hepatic alpha-1 and beta-2 adrenoceptors. To identify the role of these receptors in human hepatocellular carcinoma (HCC), the density was examined of alpha-1 and beta-2 adrenoceptors with their affinity and coupling of beta-2 adrenoceptors to adenylate cyclase in HCC tissue and in nonadjacent/nontumor tissue from the same livers. Studies were also done on healthy livers from age-matched and sex-matched patients undergoing abdominal surgery for nonhepatic diseases. Twenty-two HCC had a decrease of about 72% in alpha-1 adrenoceptor density compared with their nonadjacent/nontumor tissue and a decrease of about 40% compared with healthy controls. Nonadjacent/nontumor tissue from HCC patients had a 125% increase in alpha-1 adrenoceptor density compared with healthy livers. Twenty-three of 24 HCC had an increase of about 180% in beta adrenoceptor density compared with their nonadjacent/nontumor tissue and healthy controls. Beta adrenoceptors were coupled to adenylate cyclase, as evidenced by a guanosine triphosphate-mediated right shift in (-)-isoproterenol competition isotherms and by cyclic adenosine monophosphate (cAMP) production after stimulation with (-)-isoproterenol. The HCC tissue yielded a larger increase in cAMP than nonadjacent/nontumor tissue and healthy controls. The authors conclude that a higher density of alpha-1 adrenoceptors in nonadjacent/nontumor tissue from HCC characterizes the "healthy" part of the liver in HCC patients and that an increase in beta-2 and a decrease in alpha-1 adrenoceptor densities characterize the tumor part of the liver in human HCC.