Analyzing isolated blood vessel contraction in multi-well plates.

Organ baths have been successfully used for over a century to study the contractile or relaxation effects of drugs. Indeed, most of our understanding of vascular pharmacology is based on such in vitro studies. However, multiple parallel organ baths that require mechanical transduction consume relatively large amounts of drugs, gases, and buffers, and they take up a considerable bench space. In addition, such experiments have a high demand in terms of cost and animals, and the tissue preparation is labor intensive and slow. For these reasons, organ baths are no longer in the front line of industrial pharmacological research and they have almost disappeared from most academic laboratories. We have developed a very simple system, which can be implemented virtually in any laboratory, for the automatic analyses of rat aorta ring contraction based on optical methods and using multi-well plates. Rat aorta rings (≈0.5 mm wide) were situated in 96-multi-well plates, and the luminal vessel areas were continuously monitored using a USB camera driven by newly developed algorithms. Liquids were handled using multichannel pipettes, although these procedures can be automated for drug screening. The concentration-response curves obtained were similar to those reported in the literature using traditional force transduction techniques on isolated tissues. This system can also be used with other tissue preparations and for simultaneous fluorescence measurements. The new system described here offers a simple, cheap, and reliable alternative to the classic organ bath system.

Chalcones as positive allosteric modulators of α7 nicotinic acetylcholine receptors: a new target for a privileged structure.

The α7 acetylcholine nicotine receptor is a ligand-gated ion channel that is involved in cognition disorders, schizophrenia, pain and inflammation among other diseases. Therefore, the development of new agents that target this receptor has great significance. Positive allosteric modulators might be advantageous, since they facilitate receptor responses without directly interacting with the agonist binding site. Here we report the search for and further design of new positive allosteric modulators having the relatively simple chalcone structure. From the natural product isoliquiritigenin as starting point, chalcones substituted with hydroxyl groups at defined locations were identified as optimal and specific promoters of α7 nicotinic function. The most potent compound (2,4,2',5'-tetrahydroxychalcone, 111) was further characterized showing its potential as neuroprotective, analgesic and cognitive enhancer, opening the way for future developments around the chalcone structure.

MC1R gene variants and sporadic malignant melanoma susceptibility in the Canary Islands population.

Several MC1R variants are associated with increased risk of malignant melanoma (MM) in a variety of populations. We aim to examine the influence of the MC1R variants (RHC: D84E, R151C, R160W; NRHC: V60L, R163Q and the synonymous polymorphism T314T) on the MM risk in a population from the Canary Islands. Overall, 1,046 Caucasian individuals were included in the study. A thousand of them were genotyped for MC1R variants: 509 were sporadic MM patients and 491 were healthy control subjects from general population. The analysis was adjusted for age, sex, hair colour, eye colour, skin phototype and ancestry. We found that carriers of the R151C and R163Q variants were at an increased risk for melanoma OR 2.76 (1.59-4.78) and OR 5.62 (2.54-12.42), respectively. The risk of carrying RHC variants was 3.04 (1.90-4.86). Current study confirms the increased MM risk for R151C carriers. It also supports the association between R163Q variant and MM risk in the population on the Canary Islands, as opposed to reported on northern populations. These results highlight the importance of the sample population selection in this kind of studies.

Main pigmentary features and melanocortin 1 receptor (MC1R) gene polymorphisms in the population of the Canary Islands.

BACKGROUND: Sun exposure, light skin pigmentation, and melanocortin 1 receptor (MC1R) gene variants are independent risk factors for skin cancer. The Canary Islands have a sunny and temperate climate, but data regarding the phenotypic and genotypic risk factors among the population are lacking. METHODS: The main phenotypic features (skin color, hair color, eye color, and freckling) of 5116 healthy individuals are described. The genotypic findings of six MC1R gene variants (V60L, D84E, R150C, R160W, R163Q, and T314T) in 116 healthy individuals from a population-based cohort with at least three generations of Canary Islands' ancestry are evaluated. The variants were analyzed by SNaPshot. RESULTS: Fifty per cent of the population showed at least one phenotypic risk factor (fair skin, 34.3%; freckling, 17.4%; green or blue eyes, 16.8%; red or blonde hair, 7.8%), although brown skin (65.7%), dark eyes (83.2%), and dark hair (92.2%) prevailed. Forty-three per cent of the individuals showed at least one of the MC1R variants studied. Allelic frequencies for V60L, D84E, R150C, R160W, R163Q, and T314T were 9.1%, 1.7%, 3.0%, 0.8%, 3.0%, and 8.2%, respectively. CONCLUSION: A significant proportion of the population showed risk factors for skin cancer. The inhabitants of the Canary Islands are phenotypically and genotypically close to Mediterranean populations.