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Olvanil (N-9-Z-octadecenoyl-vanillamide) is an agonist of transient receptor potential vanilloid type 1 (TRPV1) channels that lack the pungency of capsaicin and was developed as an oral analgesic. Vanillamides are unmatched in terms of structural simplicity, straightforward synthesis, and safety compared with the more powerful TRPV1 agonists, like the structurally complex phorboid compound resiniferatoxin. We have modified the fatty acyl chain of olvanil to obtain ultra-potent analogs. The insertion of a hydroxyl group at C-12 yielded a compound named rinvanil, after ricinoleic acid, significantly less potent than olvanil (EC(50) = 6 versus 0.7 nM), but more versatile in terms of structural modifications because of the presence of an additional functional group. Acetylation and phenylacetylation of rinvanil re-established and dramatically enhanced, respectively, its potency at hTRPV1. With a two-digit picomolar EC(50) (90 pM), phenylacetylrinvanil (PhAR, IDN5890) is the most potent vanillamide ever described with potency comparable with that of resiniferatoxin (EC(50), 11 pM). Benzoyl- and phenylpropionylrinvanil were as potent and less potent than PhAR, respectively, whereas configurational inversion to ent-PhAR and cyclopropanation (but not hydrogenation or epoxidation) of the double bond were tolerated. Finally, iodination of the aromatic hydroxyl caused a dramatic switch in functional activity, generating compounds that behaved as TRPV1 antagonists rather than agonists. Since the potency of PhAR was maintained in rat dorsal root ganglion neurons and, particularly, in the rat urinary bladder, this compound was investigated in an in vivo rat model of urinary incontinence and proved as effective as resiniferatoxin at reducing bladder detrusor overactivity.

N-Arachidonoyldopamine (NADA) was recently identified as an endogenous ligand for the vanilloid type 1 receptor (VR1). Further analysis of the bovine striatal extract from which NADA was isolated indicated the existence of substances corresponding in molecular mass to N-oleoyldopamine (OLDA), N-palmitoyldopamine (PALDA), and N-stearoyldopamine (STEARDA). Quadrupole time-of-flight mass spectrometric analysis of bovine striatal extracts revealed the existence of OLDA, PALDA, and STEARDA as endogenous compounds in the mammalian brain. PALDA and STEARDA failed to affect calcium influx in VR1-transfected human embryonic kidney (HEK) 293 cells or paw withdrawal latencies from a radiant heat source, and there was no evidence of spontaneous pain behavior. By contrast, OLDA induced calcium influx (EC(50) = 36 nm), reduced the latency of paw withdrawal from a radiant heat source in a dose-dependent manner (EC(50) = 0.72 microg), and produced nocifensive behavior. These effects were blocked by co-administration of the VR1 antagonist iodo-resiniferatoxin (10 nm for HEK cells and 1 microg/50 micro;l for pain behavior). These findings demonstrate the existence of an endogenous compound in the brain that is similar to capsaicin and NADA in its chemical structure and activity on VR1. Unlike NADA, OLDA was only a weak ligand for rat CB1 receptors; but like NADA, it was recognized by the anandamide membrane transporter while being a poor substrate for fatty-acid amide hydrolase. Analysis of the activity of six additional synthetic and potentially endogenous N-acyldopamine indicated the requirement of a long unsaturated fatty acid chain for an optimal functional interaction with VR1 receptors.

Two regioisomers and 13 analogues of the putative endocannabinoid noladin ether (2-arachidonyl glyceryl ether, 2-AGE, 1) were synthesized and tested for their interaction with CB(1) receptors in rat brain membranes. The results showed that a C-20 tetra-unsaturated moiety is necessary for high affinity, and that a series of alkyl glyceryl ethers of potential occurrence in brain tissues have less affinity than 2-AGE for CB(1) receptors.

Background: Capsiate, the non-pungent ester isoster of capsaicin, and its dihydroderivative are the major capsaicinoids of sweet peppers. The remarkable difference between the sensory properties of capsaicin vs capsiate is solely due to the way the vanillyl and the acyl moieties of this basic structural motif are linked, via an amide bond in capsaicin-type compounds and via an ester bond in capsiate-type compounds., Aim of the Study: Since capsaicin induces apoptosis in tumoral cells by a vanilloid receptor type 1(VR1)-independent pathway, we examined the effects of capsiates derived from sweet peppers in the ROS generation and induction of apoptosis in tumoral cells and if these are mediated independently from VR1., Methods: We have developed an expeditious synthesis of capsiates based on the esterification of vanillol with the Mitsunobu protocol. Capsiate-induction of apoptosis, generation of reactive oxygen species and disruption of the mitochondria transmembrane potential in tumoral cell lines were measured by flow cytometry. Chemopreventive activity was studied in a two-stage mouse skin carcinogenesis assay., Results: Capsiates induce apoptosis that was preceded by an increase in the production of reactive oxygen species and by a subsequent loss of mitochondria transmembrane potential (DeltaPsi(m)). These properties were retained in simplified synthetic analogues of natural capsiates, one of which (nor-dihydrocapsiate) showed powerful chemopreventive activity., Conclusions: These results suggest that capsiates and related synthetic analogues target a variety of pathways involved in cancer development and inflammation, and have considerable potential for dietary health benefits as well as for pharmaceutical development.

Three methods for testing the comparative strength of orthopedic casts have been considered. Two of the tests, three-point-beam-bending and diametral compression, were expected to yield information about "material" strength, and a third simulated an actual cast yielding information about "structural" strength. In one study using these three methods, differences in strength were detected in the material tests, but not in the structural test. Thus, the authors believe that tests of material strength alone are insufficient to establish clinically relevant differences between the strength of orthopedic casts. Adequate testing must include structural tests like the cast-cylinder test described in this article if meaningful and clinically relevant conclusions are to be drawn regarding the comparative strength of the actual cast. Since both the three-point-beam-bending and diametral compression tests produced essentially the same results, both tests are probably not necessary. However, each of these two tests does serve to substantiate the results of the other.

The strength of five commercially available synthetic orthopedic casting products are discussed. Using three testing designs, significant differences could be consistently determined. These testing methods provide a means of comparing the various casting products on the market. The authors point out that this study was a comparison of ultimate strength only, and did not compare the other characteristics of the products. It also was noted that all these synthetic casting materials were stronger than plaster-of-Paris casting material.

The effect of hydration water temperature (dip water) on the strength of orthopedic casts is discussed. Three methods of testing are used in an attempt to detect any differences and also to assess their clinical relevance. It was found that warmer water produced stronger casts, however, the differences were not found to be clinically relevant. It is suggested that water temperature be chosen on the basis of considerations other than strength.