Intracellular drug concentrations.

Many drug targets are intracellular. To access them, a drug molecule must pass through the cell membrane, a process often facilitated or impeded by transporters. Once in the cytoplasm, basic molecules may become concentrated in organelles. To predict the pharmacologic effect accurately, there must be data concerning the concentration at the target, which is difficult to measure. Techniques that combine mass spectrometry and imaging techniques (matrix-assisted laser desorption/ionization, secondary ion mass spectrometry (SIMS), and nanoSIMS) have promise in addressing this problem.

The Concise Guide to PHARMACOLOGY 2013/14: overview.

The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties from the IUPHAR database. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. This compilation of the major pharmacological targets is divided into seven areas of focus: G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors & Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and GRAC and provides a permanent, citable, point-in-time record that will survive database updates.

Lapatinib-induced liver injury characterized by class II HLA and Gilbert's syndrome genotypes.

Lapatinib is a clinically important component of the treatment for HER2-positive metastatic breast cancer and has an acceptable safety profile. Lapatinib-associated Hy's Law cases have been characterized using human leukocyte antigen (HLA) DQA1*02:01/DRB1*07:01 and Gilbert's syndrome UGT1A1*28/*28 genotypes. The HLA-positive cases had higher alanine aminotransferase (ALT) elevation, whereas the HLA-negative cases had a higher incidence of Gilbert's syndrome. The findings of our study, which extend this HLA association to lapatinib-associated serious liver injury, emphasize the importance of Gilbert's syndrome in the interpretation of Hy's Law and may lead to methods for enhancing patient safety.

Investigative clinical pharmacology.

Clinical pharmacology is an essential discipline in the development of new medicines, but the closely specified requirements of pharmaceutical industry protocols and regulatory reviewers have limited the opportunities for curiosity-driven research. Realization is growing that there is so much that is not known about the mechanisms underlying human disease and the actions of medicines on them that research of a more exploratory kind, namely, investigative clinical pharmacology, is a priority.

Clinical pharmacology in the molecular era.

The title of this article may raise a smile from colleagues in the field of basic pharmacology. To them, pharmacology has always been about molecular interactions, and this title may simply confirm a suspicion that clinical pharmacology is mainly about semi-quantitative observations that have only a limited foundation in hard science. They are partly right, at least regarding a communication problem. In a discussion about systems biology, an exasperated engineer once remarked that biologists and physicians do not even use the same routine software packages that engineers do. Similarly, a basic pharmacologist might note that, whereas he measures drug concentrations in micromoles, the clinical pharmacologist uses micrograms per milliliters. Nevertheless, as clinical pharmacologists seek to make more quantitative observations at the molecular level in living humans, our colleagues in basic pharmacology are delving into cellular signal transduction systems governed by complex protein-protein interactions and regulated by positive and negative feedback loops. In seeking to understand these systems, they face problems that are similar to the challenge of measurement in intact humans.

Beyond genomics.

The sequencing of the human genome has already had an enormous impact on medicine, particularly with single-gene changes that predispose to a serious disease such as cystic fibrosis or the overexpression of Her2 in about one-third of breast cancers. Genetic technology has led to some very important therapeutic innovations, including the use of imatinib mesylate (Gleevec) in BCR-ABL chronic myeloid leukemia and of trastuzumab (Herceptin) in Her2-positive breast cancer, but the much anticipated explosion of new effective treatments has been more modest than expected.

Expression of tissue inhibitor of matrix metalloproteinases 1 by use of an adenoviral vector inhibits smooth muscle cell migration and reduces neointimal hyperplasia in the rat model of vascular balloon injury.

BACKGROUND: Cell migration is a major contributor to injury-induced neointimal hyperplasia and depends on alteration of the proteolytic balance within the arterial wall toward matrix breakdown. This is partly mediated by the matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). METHODS AND RESULTS: An increase in expression of biologically active and immunoreactive TIMP-1 was seen in vitro after infection of rat smooth muscle cells (SMCs) with Av1.TIMP1 (an adenoviral vector containing the human TIMP1 cDNA). Infection of rat SMCs with Av1.TIMP1 reduced migration in vitro by 27% compared with control virus-infected cells (37.6+/-4.34 versus 51+/-5.01 cells per high-power field, P<0.05). The adenoviral vector was delivered to the injured rat carotid artery, and 4 days later, immunoreactive protein was identified and migration of SMCs reduced by 60% (5.2+/-0. 5 versus 12.8+/-1.5 cells per section, P<0.05, n=5). Neointimal area 14 days after injury showed a 30% reduction in the animals receiving the Av1.TIMP1 virus compared with controls (0.09+/-0.01 versus 0. 14+/-0.01 mm2, P=0.02, n=14). CONCLUSIONS: The response to arterial balloon injury involves MMP-dependent SMC migration and can be attenuated in vivo by the transmural expression of TIMP-1 by adenoviral gene transfer.

Systolic Hypertension in Europe (Syst-Eur) trial phase 2: objectives, protocol, and initial progress. Systolic Hypertension in Europe Investigators.

The Systolic Hypertension in Europe (Syst-Eur) trial proved that blood pressure (BP) lowering therapy starting with nitrendipine reduces the risk of cardiovascular complications in older (> or = 60 years) patients with isolated systolic hypertension (systolic BP > or = 160 mm Hg and diastolic BP < 95 mm Hg). After the completion of the Syst-Eur trial on 14 February 1997, 3506 consenting patients (93.0% of those eligible) were enrolled in phase 2 of the Syst-Eur trial. This open follow-up study aims to confirm the safety of long-term antihypertensive therapy based on a dihydropyridine. To lower the sitting systolic BP below 150 mm Hg (target BP), the first-line agent nitrendipine (10-40 mg/day) may be associated with enalapril (5-20 mg/day), hydrochlorothiazide (12.5-25 mg/day), both add-on study drugs, or if required any other antihypertensive agent. On 1 November 1998, 3248 patients were still being followed, 86 patients had proceeded to non-supervised follow-up, and 43 had died. The median follow-up in Syst-Eur 2 was 14.3 months. At the last available visit, systolic/diastolic BP in the patients formerly randomised to placebo (n = 1682) or active treatment (n = 1824), had decreased by 13.2/5.2 mm Hg and by 4.6/1.6 mm Hg, respectively, so that the between-group BP difference was 1.7 mm Hg systolic (95% Ci: 0.8 to 2.6 mm Hg; P < 0.001) and 0.9 mm Hg diastolic (95% Cl: 0.4 to 1.5 mm mm Hg; P < 0.001). At the beginning of Syst-Eur 2, the goal BP was reached by 25.4% and 50.6% of the former placebo and active-treatment groups; at the last visit these proportions were 55.9% and 63.1%, respectively. At that moment, 45.9% of the patients were on monotherapy with nitrendipine, 29.3% took nitrendipine in combination with other study drugs. Until the end of 2001, BP control of the Syst-Eur 2 patients will be further improved. Cardiovascular complications and adverse events, such as cancer or gastro-intestinal bleeding, will be monitored and validated by blinded experts.

TIMP-4 is regulated by vascular injury in rats.

The role of basement membrane-degrading matrix metalloproteinases (MMPs) in enabling vascular smooth muscle cell migration after vascular injury has been established in several animal models. In contrast, the role of their native inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), has remained unproven despite frequent coregulation of MMPs and TIMPs in other disease states. We have investigated the time course of expression and localization of TIMP-4 in rat carotid arteries 6 hours, 24 hours, 3 days, 7 days, and 14 days after balloon injury by in situ hybridization, immunohistochemistry, and Western blot analysis. TIMP-4 protein was present in the adventitia of injured carotid arteries from 24 hours after injury. At 7 and 14 days after injury, widespread immunostaining for TIMP-4 was observed throughout the neointima, media, and adventitia of injured arteries. Western blot analysis confirmed the quantitative increase in TIMP-4 protein at 7 and 14 days. In situ hybridization detected increased expression of TIMP-4 as early as 24 hours after injury and a marked induction in neointimal cells 7 days after injury. We then studied the effect of TIMP-4 protein on the migration of smooth muscle cells through a matrix-coated membrane in vitro and demonstrated a 53% reduction in invasion of rat vascular smooth muscle cells. These data and the temporal relationship between the upregulation of TIMP-4, its accumulation, and the onset of collagen deposition suggest an important role for TIMP-4 in the proteolytic balance of the vasculature controlling both smooth muscle migration and collagen accumulation in the injured arterial wall.

Angiotensin-converting-enzyme gene insertion/deletion polymorphism and response to physical training.

BACKGROUND: The function of local renin-angiotensin systems in skeletal muscle and adipose tissue remains largely unknown. A polymorphism of the human angiotensin converting enzyme (ACE) gene has been identified in which the insertion (I) rather than deletion (D) allele is associated with lower ACE activity in body tissues and increased response to some aspects of physical training. We studied the association between the ACE gene insertion or deletion polymorphism and changes in body composition related to an intensive exercise programme, to investigate the metabolic effects of local human renin-angiotensin systems. METHODS: We used three independent methods (bioimpedance, multiple skinfold-thickness assessment of whole-body composition, magnetic resonance imaging of the mid-thigh) to study changes in body composition in young male army recruits over 10 weeks of intensive physical training. FINDINGS: Participants with the II genotype had a greater anabolic response than those with one or more D alleles for fat mass (0.55 vs -0.20 kg, p=0.04 by bioimpedance) and non-fat mass (1.31 vs -0.15 kg, p=0.01 by bioimpedance). Changes in body morphology with training measured by the other methods were also dependent on genotype. INTERPRETATION: II genotype, as a marker of low ACE activity in body tissues, may conserve a positive energy balance during rigorous training, which suggests enhanced metabolic efficiency. This finding may explain some of the survival and functional benefits of therapy with ACE inhibitors.

Local gene delivery of recombinant adenoviruses to the rat carotid artery in vivo.

A number of animal models are available to investigators wishing to study the use of gene transfer to prevent neointimal formation after vascular injury. The majority are models of primary vascular injury rather than the human situation, where recurrence of a stenosis occurs in an abnormal blood vessel treated by angioplasty. The main animal models used to study vascular balloon injury or angioplasty are the rat carotid, the rabbit iliac, the pig coronary and carotid models, and, less frequently, the dog coronary and primate saphenous or iliac models. A healthy level of skepticism exists about many of these animal models following the success of angiotensin-converting enzyme inhibitors in preventing neointima formation in the rat model but their failure to prevent human restenosis (1,2). Each model, however, has a particular suitability to investigate different aspects of the balloon injury process and all are suitable for gene transfer studies.

Randomised double-blind comparison of placebo and active treatment for older patients with isolated systolic hypertension. The Systolic Hypertension in Europe (Syst-Eur) Trial Investigators.

BACKGROUND: Isolated systolic hypertension occurs in about 15% of people aged 60 years or older. In 1989, the European Working Party on High Blood Pressure in the Elderly investigated whether active treatment could reduce cardiovascular complications of isolated systolic hypertension. Fatal and non-fatal stroke combined was the primary endpoint. METHODS: All patients (> 60 years) were initially started on masked placebo. At three run-in visits 1 month apart, their average sitting systolic blood pressure was 160-219 mm Hg with a diastolic blood pressure lower than 95 mm Hg. After stratification for centre, sex, and previous cardiovascular complications, 4695 patients were randomly assigned to nitrendipine 10-40 mg daily, with the possible addition of enalapril 5-20 mg daily and hydrochlorothiazide 12.5-25.0 mg daily, or matching placebos. Patients withdrawing from double-blind treatment were still followed up. We compared occurrence of major endpoints by intention to treat. FINDINGS: At a median of 2 years' follow-up, sitting systolic and diastolic blood pressures had fallen by 13 mm Hg and 2 mm Hg in the placebo group (n = 2297) and by 23 mm Hg and 7 mm Hg in the active treatment group (n = 2398). The between-group differences were systolic 10.1 mm Hg (95% CI 8.8-11.4) and diastolic, 4.5 mm Hg (3.9-5.1). Active treatment reduced the total rate of stroke from 13.7 to 7.9 endpoints per 1000 patient-years (42% reduction; p = 0.003). Non-fatal stroke decreased by 44% (p = 0.007). In the active treatment group, all fatal and non-fatal cardiac endpoints, including sudden death, declined by 26% (p = 0.03). Non-fatal cardiac endpoints decreased by 33% (p = 0.03) and all fatal and non-fatal cardiovascular endpoints by 31% (p < 0.001). Cardiovascular mortality was slightly lower on active treatment (-27%, p = 0.07), but all-cause mortality was not influenced (-14%; p = 0.22). INTERPRETATION: Among elderly patients with isolated systolic hypertension, antihypertensive drug treatment starting with nitrendipine reduces the rate of cardiovascular complications. Treatment of 1000 patients for 5 years with this type of regimen may prevent 29 strokes or 53 major cardiovascular endpoints.

Association of angiotensin-converting enzyme gene I/D polymorphism with change in left ventricular mass in response to physical training.

BACKGROUND: The absence (deletion allele [D]) of a 287-base pair marker in the ACE gene is associated with higher ACE levels than its presence (insertion allele [I]). If renin-angiotensin systems regulate left ventricular (LV) growth, then individuals of DD genotype might show a greater hypertrophic response than those of II genotype. We tested this hypothesis by studying exercise-induced LV hypertrophy. METHODS AND RESULTS: Echocardiographically determined LV dimensions and mass (n=140), electrocardiographically determined LV mass and frequency of LV hypertrophy (LVH) (n=121), and plasma brain natriuretic peptide (BNP) levels (n=49) were compared at the start and end of a 10-week physical training period in male Caucasian military recruits. Septal and posterior wall thicknesses increased with training, and LV mass increased by 18% (all P<.0001). Response magnitude was strongly associated with ACE genotype: mean LV mass altered by +2.0, +38.5, and +42.3 g in II, ID and DD, respectively (P<.0001). The prevalence of electrocardiographically defined LVH rose significantly only among those of DD genotype (from 6 of 24 before training to 11 of 24 after training, P<.01). Plasma brain natriuretic peptide levels rose by 56.0 and 11.5 pg/mL for DD and II, respectively (P<.001). CONCLUSIONS: Exercise-induced LV growth in young males is strongly associated with the ACE I/D polymorphism.

Urinary leukotriene E4 levels in patients with atopic dermatitis.

Leukotriene synthesis may be increased in a variety of inflammatory diseases. Urinary leukotriene E4 is a stable metabolite of leukotrienes C4 and D4 which has previously been found to be increased in exacerbations of severe asthma and after antigen inhalation. Levels of urinary LTE4 in seven patients during and after a severe flare of atopic dermatitis were measured by high-performance liquid chromatography (HPLC) and radioimmunoassay (RIA). Mean urinary LTE4 levels (+/- SEM) were not increased during (16.7 +/- 3.7 pg/mumol) or after (16.9 +/- 4.8 mumol) the acute exacerbation of atopic dermatitis when compared with the normal range (mean = 23.8 [95% confidence interval 19.9-28.2] pg/mumol creatinine). These findings do not provide evidence of cysteine leukotriene involvement in the pathogenesis of atopic dermatitis.