Differing effects of epinephrine, norepinephrine, and vasopressin on survival in a canine model of septic shock

During sepsis, limited data on the survival effects of vasopressors are available to guide therapy. Therefore, we compared the effects of three vasopressors on survival in a canine septic shock model. Seventy-eight awake dogs infected with differing doses of intraperitoneal Escherichia coli to produce increasing mortality were randomized to receive epinephrine (0.2, 0.8, or 2.0 μg·kg−1·min−1), norepinephrine (0.2, 1.0, or 2.0 μg·kg−1·min−1), vasopressin (0.01 or 0.04 U/min), or placebo in addition to antibiotics and fluids. Serial hemodynamic and biochemical variables were measured. Increasing doses of bacteria caused progressively greater decreases in survival ( P < 0.06), mean arterial pressure (MAP) ( P < 0.05), cardiac index (CI) ( P < 0.02), and ejection fraction (EF) ( P = 0.02). The effects of epinephrine on survival were significantly different from those of norepinephrine and vasopressin ( P = 0.03). Epinephrine had a harmful effect on survival that was significantly related to drug dose ( P = 0.02) but not bacterial dose. Norepinephrine and vasopressin had beneficial effects on survival that were similar at all drug and bacteria doses. Compared with concurrent infected controls, epinephrine caused greater decreases in CI, EF, and pH, and greater increases in systemic vascular resistance and serum creatinine than norepinephrine and vasopressin. These epinephrine-induced changes were significantly related to the dose of epinephrine administered. In this study, the effects of vasopressors were independent of severity of infection but dependent on the type and dose of vasopressor used. Epinephrine adversely affected organ function, systemic perfusion, and survival compared with norepinephrine and vasopressin. In the ranges studied, norepinephrine and vasopressin have more favorable risk-benefit profiles than epinephrine during sepsis.

Cerebrospinal fluid beta-amyloid1-42 and tau in control subjects at risk for Alzheimer's disease: the effect of APOE epsilon4 allele

BACKGROUND

Cerebrospinal fluid (CSF) measures of beta-amyloid(1-42) and tau are linked with the known neuropathology of Alzheimer's disease (AD). Numerous lines of evidence have also suggested that individuals with at least one APOE epsilon4 allele on chromosome 19 are at increased risk of developing AD. We tested these CSF markers in groups of subjects with AD and healthy older control subjects, using the absence or presence of the APOE epsilon4 allele as a predictive variable in the search for possible prognostic biomarkers of AD.

METHODS

We assessed the levels of beta-amyloid(1-42) and total tau in the CSF of 292 subjects (142 control subjects and 150 subjects with mild-to-moderate AD), who were research participants at the National Institute of Mental Health. The group of control subjects was enriched with a high percentage of subjects with a positive family history of AD. All subjects underwent extensive global cognitive testing.

RESULTS

When divided according to the absence or presence of the APOE epsilon4 allele, the control subjects with at least one epsilon4 allele had significantly lower CSF beta-amyloid(1-42) but not tau levels than control subjects without an APOE epsilon4 allele (p < .01). As expected, the AD patients had lower levels of CSF beta-amyloid(1-42) and higher CSF tau levels than the normal control group (p < .01).

CONCLUSIONS

The association of APOE epsilon4 allele and lower, more AD-like levels of CSF beta-amyloid(1-42) in older control subjects is consistent with previous studies showing possible neuroimaging and cognitive abnormalities with epsilon4 carriers and suggests that CSF beta-amyloid(1-42) decreases might represent an early biomarker of AD. Longitudinal follow-up is of course required to verify whether this biomarker is indeed predictive of clinical conversion to AD.

Is thyroid hormone suppression therapy prothrombotic?

The purpose of this study was to determine whether chronic thyroid hormone suppression therapy (THST) is prothrombotic. We obtained blood samples from 14 thyroid cancer patients while on THST and after they had become hypothyroid for radioiodine whole-body scanning and therapy. Prothrombin fragment 1 + 2, fibrinogen, factor VIII, antithrombin, tissue plasminogen activator antigen (tPA), plasminogen activator inhibitor 1 (PAI-1), PAI-1/tPA, and C-reactive protein were significantly (P < 0.05) higher in the hyper- than in the hypothyroid state, whereas protein C and plasmin-antiplasmin complexes were significantly lower during the hyperthyroid period. When the 10 female patients were hyperthyroid, their levels of prothrombin fragment 1 + 2, fibrinogen, protein S, antithrombin, tPA, PAI-1, and PAI-1/tPA were significantly higher (P </= 0.05) than in healthy female controls, whereas when the female patients were hypothyroid, their antithrombin and plasmin-antiplasmin were lower and their protein S was higher than in controls. Factor II, plasminogen, and D-dimer were not significantly affected by the thyroid status in either assessment. In conclusion, we found evidence that the majority of patients treated with THST have a prothrombotic profile.

Targeting of scavenger receptor class B type I by synthetic amphipathic alpha-helical-containing peptides blocks lipopolysaccharide (LPS) uptake and LPS-induced pro-inflammatory cytokine responses in THP-1 monocyte cells

Human scavenger receptor class B type I, CLA-1, mediates lipopolysaccharide (LPS) binding and internalization (Vishnyakova, T. G., Bocharov, A. V., Baranova, I. N., Chen, Z., Remaley, A. T., Csako, G., Eggerman, T. L., and Patterson, A. P. (2003) J. Biol. Chem. 278, 22771-22780). Because one of the recognition motifs in SR-B1 ligands is the anionic amphipathic alpha-helix, we analyzed the effects of model amphipathic alpha-helical-containing peptides on LPS uptake and LPS-stimulated cytokine production. The L-37pA model peptide, containing two class A amphipathic helices, bound with high affinity (K(d) = 0.94 microg/ml) to CLA-1-expressing HeLa cells with a 10-fold increased capacity when compared with mock transfected HeLa cells. Both LPS and L-37pA colocalized with anti-CLA-1 antibody and directly bound CLA-1 as determined by cross-linking. SR-BI/CLA-1 ligands such as HDL, apoA-I, and L-37pA efficiently competed against iodinated L-37pA. Bacterial LPS, lipoteichoic acid, and hsp60 also competed against iodinated L-37pA. Model peptides blocked uptake of iodinated LPS in both mock transfected and CLA-1-overexpressing HeLa cells. Bound and internalized Alexa-L-37pA and BODIPY-LPS colocalized at the cell surface and perinuclear compartment. Both ligands were predominantly transported to the Golgi complex, colocalizing with the Golgi markers bovine serum albumin-ceramide, anti-Golgin97 antibody, and cholera toxin subunit B. A 100-fold excess of L-37pA nearly eliminated BODIPY-LPS binding and internalization. L-37pA and its d-amino acid analogue, D-37pA peptide were similarly effective in blocking LPS, Gram-positive bacterial wall component lipoteichoic acid and bacterial heat shock protein Gro-EL-stimulated cytokine secretion in THP-1 cells. In the same culture media used for the cytokine stimulation study, neither L-37pA nor D-37pA affected the Limulus amebocyte lysate activity of LPS, indicating that LPS uptake and cytokine stimulation were blocked independently of LPS neutralization. These results demonstrate that amphipathic helices of exchangeable apolipoproteins may represent a general host defense mechanism against inflammation.

Association of serum antibodies to heat-shock protein 65 with coronary calcification levels: suggestion of pathogen-triggered autoimmunity in early atherosclerosis

BACKGROUND

Previous studies demonstrated an association between antibodies to mycobacterial heat-shock protein 65 (mHSP65) and carotid artery thickening. We examined whether mHSP65 antibodies are associated with levels of coronary calcification that appear to reflect preclinical coronary artery disease (CAD).

METHODS AND RESULTS

Serum specimens from 201 healthy asymptomatic subjects (52% male; mean age, 56.6 years) undergoing electron-beam computed tomographic imaging were used to measure levels of mHSP65 and human HSP60 antibodies and antibodies to several infectious pathogens. We found that 84% of the study subjects had anti-mHSP65 IgG antibodies. Mean titers of mHSP65 antibodies were higher (1:394 versus 1:267, P=0.012) in individuals with than in those without elevated levels of coronary calcium (calcium score > or =150). Increasing titers of mHSP65 antibodies were significantly associated, in a dose-response manner, with elevated levels of coronary calcification. Individuals with the highest titers of mHSP65 antibodies (> or =1:800) had an adjusted odds ratio (OR) of 14.3 for having elevated coronary calcium (P=0.004). Association of mHSP65 antibodies with elevated coronary calcification levels was independent of CAD risk factors after multivariate adjustment (P=0.037). Interestingly, mHSP65 antibody titers were correlated with Helicobacter pylori infection (P=0.004), which maintained significance after adjustment for CAD risk factors and seropositivities to other pathogens (adjusted OR, 3.1; 95% CI, 1.4 to 6.6). No association was found between antibodies to human HSP60 and levels of coronary calcification.

CONCLUSIONS

Antibodies to mHSP65 are associated with elevated levels of coronary calcification and correlated with H pylori infection, suggesting that pathogen-triggered autoimmunity plays a role in early atherosclerosis.

Long-cycle structured intermittent versus continuous highly active antiretroviral therapy for the treatment of chronic infection with human immunodeficiency virus: effects on drug toxicity and on immunologic and virologic parameters

We evaluated the effect of long-cycle structured intermittent therapy (SIT; 4 weeks without highly active antiretroviral therapy [HAART] followed by 8 weeks with HAART) versus continuous HAART. The study was prematurely terminated to new enrollment because of the emergence of genetic mutations associated with resistance to antiretroviral drugs in 5 patients. After 48 weeks, there was no significant difference between groups in lipid, hepatic transaminase, and C-reactive protein levels in 41 patients. Although there were no differences in CD4(+) or CD8(+) T cell counts or the percentage of cells that were CD4(+)CD25(+), CD8(+)CD25(+), or CD4(+)DR(+), patients who received SIT had a significantly higher percentage of CD8(+)CD38(+) and CD8(+)DR(+) cells. There was no clear autoimmunization effect by immunologic or virologic parameters. There was no benefit to long-cycle SIT versus continuous HAART with regard to certain toxicity, immunologic, or virologic parameters.

Binding and internalization of lipopolysaccharide by Cla-1, a human orthologue of rodent scavenger receptor B1

Scavenger receptor, class B, type I (SR-BI) mediates selective uptake of high density lipoprotein (HDL) cholesteryl ester. SR-BI recognizes HDL, low density lipoprotein (LDL), exchangeable apolipoproteins, and protein-free lipid vesicles containing negatively charged phospholipids. Lipopolysaccharides (LPS) are highly glycosylated anionic phospholipids contributing to septic shock. Despite significant structural similarities between anionic phospholipids and LPS, the role of SR-BI in LPS uptake is unknown. Cla-1, the human SR-BI orthologue, was determined to be a LPS-binding protein and endocytic receptor mediating the binding and internalization of lipoprotein-free, monomerized LPS. LPS strongly competed with HDL, lipidfree apoA-I and apoA-II for HDL binding to the mouse RAW cells. Stably transfected HeLa cells expressing Cla-1-bound LPS with a Kd of about 16 microg/ml, and had a 3-4-fold increase in binding capacity and LPS uptake. Bodipy-labeled LPS uptake was found to initially accumulate in the plasma membrane and subsequently in a perinuclear region identified predominantly as the Golgi complex. Bodipy-LPS and Alexa-apoA-I had staining that colocalized on the cell surface and intracellularly indicating similar transport mechanisms. When associated with HDL, LPS uptake was increased in Cla-1 overexpressing HeLa cells by 5-10-fold. Cla-1-associated 3H-LPS uptake exceeded 125I-apolipoprotein uptake by 5-fold indicating a selective LPS uptake. Upon interacting with Cla-1 overexpressing HeLa cells, the complex (Bodipy-LPS/Alexa 488 apolipoprotein-labeled HDL) bound and was internalized as a holoparticle. Intracellularly, LPS and apolipoproteins were sorted to different intracellular compartments. With LPS-associated HDL, intracellular LPS co-localized predominantly with transferrin, indicating delivery to an endocytic recycling compartment. Our study reveals a close similarity between Cla-1-mediated selective LPS uptake and the recently described selective lipid sorting by rodent SR-BI. In summary, Cla-1 was found to bind and internalize monomerized and HDL-associated LPS, indicating that Cla-1 may play important role in septic shock by affecting LPS cellular uptake and clearance.

Increased serum levels of heat shock protein 70 are associated with low risk of coronary artery disease

OBJECTIVE

Previous studies suggest that heat shock protein (HSP) 60 has a contributory role in atherosclerosis development. We examined whether circulating HSP70 protein and anti-HSP70 antibodies are associated with coronary artery disease (CAD).

METHODS AND RESULTS

Blood samples from 421 patients (62% men, mean age 57 years) evaluated for CAD by coronary angiography were tested. Serum HSP70 was detectable in 67% of study subjects with levels ranging from 0.2 to 27.1 ng/mL (mean, 1.08; median, 0.5). HSP70 levels were higher in non-CAD patients than CAD patients (median, 0.72 versus 0.34; P=0.0006). Individuals with HSP70 levels above the median (0.5 ng/mL) had half the risk of CAD than individuals with levels below the median (adjusted odds ratio, 0.52; 95% confidence limit, 0.32 to 0.86). The association of high HSP70 levels with low CAD risk was independent of traditional CAD risk factors (P=0.011). Disease severity (number of diseased vessels) was also inversely associated with HSP70 protein levels (P=0.010). The adjusted odds ratio of having multivessel disease for patients with high HSP70 protein levels was 0.54 (95% confidence limit, 0.36 to 0.81). In contrast, no association between anti-HSP70 IgG seropositivity and the prevalence of CAD was found (P=0.916).

CONCLUSIONS

These data provide the first evidence that high levels of human HSP70 are associated with the low CAD risk, probably through its multiple protective effects on a cell's response to stress.

Sympathetic blockade in a canine model of gram-negative bacterial peritonitis

We investigated, in a well-established canine model of human sepsis, the effects of two different techniques of sympathetic blockade during bacterial peritonitis on pain relief, hemodynamics, and survival rate. Twenty-two purpose-bred beagles (12-28 months old, weighing 10-12 kg) were studied. Fourteen animals received an epidural infusion of bupivicaine and morphine, and the other eight received either a celiac plexus block (n = 4) or a sham block (n = 4). Eighteen of the 22 animals received an intraperitoneal challenge of Escherichia coli (1-10 x 10(9) CFU kg(-1) body weight). At comparable doses of intraperitoneal-implanted E. coli (2.5-5 x 10(9) CFU kg(-1) body weight), the addition of sympathetic blockade produced a synergistic decrease in survival times (P = 0.002) and mean left ventricular ejection fraction (P = 0.008), and increase in creatinine levels (P = 0.02). There was also a significant increase in tumor necrosis factor (TNF) levels (P = 0.004) and decrease in blood endotoxin clearance (P = 0.006) associated with sympathetic blockade during sepsis. The celiac plexus-blocked animals had no improvement in pain scores, and subjectively looked clinically worse than animals with sepsis without a celiac plexus block. In contrast, the epidural block was effective in blocking the pain and discomfort associated with low lethality doses of intraperitoneal bacteria reflected by no increase in pain scores compared with animals not receiving bacterial challenge. This study shows that during severe bacterial peritonitis, maintenance of sympathetic tone irrespective of pain relief provided is necessary for clearance of bacterial toxins, control of proinflammatory mediator release, hemodynamic stability, and survival.

Divergent nitric oxide bioavailability in men and women with sickle cell disease

BACKGROUND

Although reduced endothelial nitric oxide (NO) bioavailability has been demonstrated in arteriosclerotic vascular disease, the integrity of this system in sickle cell disease remains uncertain.

METHODS AND RESULTS

We measured forearm blood flow in 21 patients with sickle cell disease (hemoglobin SS genotype) and 18 black control subjects before and after intra-arterial infusions of acetylcholine, nitroprusside, and the NO synthase inhibitor NG-monomethyl-L-arginine (L-NMMA). Endothelium-dependent vasodilation, measured by the percent increase in flow induced by acetylcholine infusion, was significantly greater than in controls (252+/-37% for patients versus 134+/-24% for controls; P<0.0001). However, there was a large sex difference in blood flow responses between female and male patients (340+/-46% versus 173+/-41%; P=0.035). Similarly, basal NO bioactivity, as measured by the percent decrease in flow induced by L-NMMA, was depressed in male compared with female patients (-17+/-5% versus -34+/-4%; P=0.01), as was the response to nitroprusside (86+/-21% versus 171+/-22%; P=0.008). L-NMMA reduced the blood flow response to acetylcholine in women, but not in men. Sex differences in vascular cell adhesion molecule-1 were appreciated, with significant correlations between levels of soluble vascular cell adhesion molecule-1 and blood flow responses to L-NMMA and nitroprusside (r=0.53, P=0.004 and r=-0.66, P<0.001, respectively).

CONCLUSIONS

NO bioavailability and NO responsiveness are greater in women than in men with sickle cell disease and determines adhesion molecule expression. Endothelium-dependent blood flows are largely non-NO mediated in male patients. These results provide a possible mechanism for reported sex differences in sickle cell disease morbidity and mortality and provide a basis for novel pharmacological interventions.

Statin attenuates increase in C-reactive protein during estrogen replacement therapy in postmenopausal women

BACKGROUND

HMG-CoA reductase inhibitor (statin) therapy reduces cardiovascular risk, mechanisms of which may include diminished arterial inflammation, as suggested by reduction in levels of C-reactive protein (CRP). Because oral estrogens increase CRP in postmenopausal women, with potential inflammatory and thrombotic consequences that could compromise any benefit to cardiovascular risk, we determined whether the coadministration of a statin might modify the estrogenic effect on CRP.

METHODS AND RESULTS

In a double-blind, 3-period crossover study, 28 postmenopausal women (average LDL cholesterol 163+/-36 mg/dL) were randomly assigned to daily conjugated equine estrogens (CEEs) 0.625 mg, simvastatin 10 mg, or their combination for 6 weeks, with each treatment period separated by 6 weeks. CEEs increased median CRP levels from 0.27 to 0.46 mg/dL, simvastatin decreased CRP from 0.29 to 0.28 mg/dL, and the therapies combined increased CRP from 0.28 to 0.36 mg/dL (all P< or =0.02 versus respective baseline values). Post hoc testing showed that the 29% increase in CRP on the combination of CEEs with simvastatin was significantly less than the 70% increase in CRP on CEEs alone (P<0.05). The effect of combination therapy on CRP levels did not correlate with baseline CRP or with baseline or treatment-induced changes in levels of interleukin-6, lipoproteins, or flow-mediated dilation of the brachial artery as a measure of nitric oxide bioactivity.

CONCLUSIONS

The combination of statin with estrogen may attenuate the potential harmful effects of estrogen therapy in postmenopausal women and maximize any benefit to cardiovascular risk.

Toxicity of a first-generation adenoviral vector in rhesus macaques

We constructed a first-generation adenovirus vector (AVC3FIX5) that we used to assess the rhesus macaque as a nonhuman primate model for preclinical testing of hemophilia B gene therapy vectors. Although we succeeded in our primary objective of demonstrating expression of human factor IX we encountered numerous toxic side effects that proved to be dose limiting. Following intravenous administration of AVC3FIX5 at doses of 3.4 x 10(11) vector particles/kg to 3.8 x 10(12) vector particles/kg, the animals in our study developed antibodies against human factor IX, and dose-dependent elevations of enzymes specific for liver, muscle, and lung injury. In addition, these animals showed dose-dependent prolongation of clotting times as well as acute, dose-dependent decreases in platelet counts and concomitant elevation of fibrinogen and von Willebrand factor. These abnormalities may be caused by the direct toxic effects of the adenovirus vector itself, or may result indirectly from the accompanying acute inflammatory response marked by elevations in IL-6, a key regulator of the acute inflammatory response. The rhesus macaque may be a useful animal model in which to evaluate mechanisms of adenovirus toxicities that have been encountered during clinical gene therapy trials.

Effects of thyroid hormone suppression therapy on adverse clinical outcomes in thyroid cancer

BACKGROUND

Long-term thyroid hormone (TH) therapy aiming at the suppression of serum thyrotropin (TSH) has been traditionally used in the management of well differentiated thyroid cancer (ThyrCa). However, formal validation of the effects of thyroid hormone suppression therapy (THST) through randomized controlled trials is lacking. Additionally, the role - if any - of TSH effect at low ambient concentrations upon human thyroid tumorigenesis remains unclear.

AIM

Evaluation of the effect of THST on the clinical outcomes of papillary and/or follicular ThyrCa.

METHODS

By using a quantitative research synthesis approach in a cumulative ThyrCa cohort, we evaluated the effect of THST on the likelihood of major adverse clinical events (disease progression/recurrence and death). A total of 28 clinical trials published during the period 1934-2001 were identified; only 10 were amenable to meta-analysis. Causality was assessed by Hill criteria.

RESULTS

Out of 4, 174 patients with ThyrCa, 2, 880 (69%) were reported as being on THST. Meta-analysis showed that the group of patients who received THST had a decreased risk of major adverse clinical events (RR = 0.73; Cl = 0.60-0.88; P < 0.05). Further, by applying a Likert scale, 15/17 interpretable studies showed either a 'likely' or 'questionable' beneficial effect of THST. Assessment of causality between TSHT and reduction of major adverse clinical events suggested a probable association.

CONCLUSIONS

THST appears justified in ThyrCa patients following initial therapy. As most primary studies were imperfect, future research will better define the effect of THST upon ThyrCa clinical outcomes.

Exaggerated levothyroxine malabsorption due to calcium carbonate supplementation in gastrointestinal disorders

OBJECTIVE

To describe a patient with primary hypothyroidism in whom ingestion of levothyroxine with calcium carbonate led to markedly elevated serum thyrotropin concentrations.

CASE SUMMARY

A 61-year-old white woman with primary hypothyroidism, systemic lupus erythematosus, celiac disease, and history of Whipple resection for pancreatic cancer was euthyroid with levothyroxine 175-188 micrograms/d. After taking a high dose of calcium carbonate (1250 mg three times daily) with levothyroxine, she developed biochemical evidence of hypothyroidism (thyrotropin up to 41.4 mU/L) while remaining clinically euthyroid. Delaying calcium carbonate administration by four hours returned her serum thyrotropin to a borderline high concentration (5.7 mU/L) within a month. Serum concentrations of unbound and total thyroxine and triiodothyronine tended to decrease, but remained borderline low to normal while the patient concomitantly received levothyroxine and calcium carbonate.

DISCUSSION

Concomitant administration of levothyroxine and calcium carbonate often results in levothyroxine malabsorption. While in most patients the clinical consequences of this interaction, even with prolonged exposure, are relatively small, overt hypothyrodism may develop in patients with preexisting malabsorption disorders. However, as the current case illustrates, the clinical manifestations of the initial levothyroxine deficit may not always be apparent and, of all usual laboratory thyroid function tests, only thyrotropin measurement will reliably uncover the exaggerated levothyroxine malabsorption.

CONCLUSIONS

Decreased absorption of levothyroxine when given with calcium carbonate may be particularly pronounced in patients with preexisting malabsorption disorders. Once recognized, a change in drug administration schedule usually minimizes or eliminates this interaction.

Treatment options for a patient experiencing pruritic rash associated with transdermal testosterone: a review of the literature

A 22-year-old man with hypogonadotropic hypogonadism was receiving monthly intramuscular injections of testosterone replacement therapy. The patient refused to self-administer the injections because of discomfort, so the therapy was switched to testosterone patches. He experienced a pruritic, macular, erythematous rash underneath the reservoir area of two different transdermal formulations, which did not improve after pretreatment with topical corticosteroids. Eventually, he tolerated application of a testosterone gel and his serum testosterone levels returned to normal after 1 month of therapy. Commercially available and investigational testosterone products and therapeutic monitoring guidelines for androgen replacement are reviewed.

Role of angiotensin II type 1 receptor in the regulation of cellular adhesion molecules in atherosclerosis

BACKGROUND

Inflammation is a central feature of coronary artery disease (CAD) that is characterized by increased expression of cellular adhesion molecules with the exception of L-selectin. L-selectin is a leukocyte adhesion molecule that is rapidly shed after leukocyte activation so that it appears to be decreased in CAD. The renin-angiotensin system (RAS) is implicated in atherogenesis and up-regulates these molecules.

OBJECTIVES

The aim of this study was to investigate the effect of angiotensin type 1 (AT1) receptor antagonism on serum and leukocyte adhesion molecule expression in patients with CAD. Blood samples were collected from 31 patients before and after 8 weeks of treatment with losartan (44 +/- 2 mg/d, mean +/- SE), an AT1 receptor antagonist. We measured serum intercellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial-leukocyte adhesion molecule, and C-reactive protein (CRP). By flow cytometry, we also measured the expression of leukocyte CD11a, CD11b, CD11c, CD18, CD31, CD49d, and CD62L (L-selectin) in 13 patients.

RESULTS

Treatment with losartan decreased systolic blood pressure (141 +/- 3 vs 135 +/- 4 mm Hg, P =.04) and increased plasma renin activity (1.2 +/- 0.4 vs 2.7 +/- 0.5 ng/mL/h, P =.001). There was a significant increase in L-selectin expression on monocytes (86 +/- 6 vs 118 +/- 10 MESF units, P =.007), lymphocytes (52 +/- 10 vs 79 +/- 8, P =.01), and granulocytes (124 +/- 7 vs 156 +/- 18, P =.056). However, there were no changes in the other leukocyte and serum adhesion molecules or CRP.

CONCLUSIONS

These findings suggest that AT1 receptor antagonism selectively modulates L-selectin expression on leukocytes and that endogenous stimulation of AT1 receptors by the RAS contributes to the activation of leukocytes and decreased expression of L-selectin in CAD.