Allergic contact dermatitis due to nickel salts is common. It isexperiments, thus making comparisons across studies diYcult therefore important to measure the permeation of these salts(1). through the stratum corneum (SC ), the primary rate-limitingAs a well-known irritant and allergen, nickel causes both domain in skin. An advanced diVusion system and analytical immediate and delayed, speci c and non-speci c type allergy techniques now enable better measurement of the ux than was reactions following dermal exposure (2-4). The dermatotoxicpossible in earlier experiments. Human SC was prepared by ology of nickel compounds presents a major scienti c challenge trypsinization of dermatomed cadaver leg skin. The diVusion owing to the apparent paradoxes observed in its behavior in system included diVusion cells with a spiral line. Aqueous contact with the epidermis, so several signi cant issues await solutions of nickel salts (Ni(NO 3 ) 2 , NiSO 4 , NiCl 2 and resolution reconciled through appropriate experimentation. To
Ni(Õ OOCCH3 ) 2 at 1% Ni2+ concentration) were used as the date, the most comprehensive study of skin permeation by donor solution (400 lL / cell ). The receptor uid, pure water, inorganic nickel salts was performed in vitro on full-thickness was collected up to 96 h after application of the donor solutions.skin (5). The present study focuses only on the permeation of Nickel concentrations in the donor and receptor uid, as well as nickel from various salts across the uppermost layer of the in the SC, were analysed using inductively coupled plasma mass epidermis, the stratum corneum (SC ). With the aid of sophistspectrometry (ICP-MS) with a con dence limit of 0.5 ppb.icated analytical methods such as inductively coupled plasma Based on the total recovery of nickel from the experiments, mass spectroscopy (ICP-MS ) (6, 7), it is now possible to about 98% of the dose remained in the donor solution, whereas accurately detect ultra-trace amounts of the metal in biological 1% or less was retained in SC and less than 1% was found in substrates, such as SC tissue or the donor and receptor phases the receptor uid. Following an early surge, nickel permeates from in vitro studies, yielding a suYciently accurate picture of slowly across SC. The steady-state permeability coeYcients of metal adsorption and absorption. nickel were calculated from the ux data (approximately This investigation was designed to clarify the eVect the 5.2-8.5´10Õ 7 cm / h) with no signi cant diVerence among the counter ions sulfate, chloride, nitrate and acetate may have salts. The results concur in principle with earlier studies conon in vitro diVusion of aqueous nickel solutions applied at a ducted using the full-thickness human skin in vitro, and suggest 1% nickel concentration level. We measured respective steadythat in vivo nickel ions may permeate simultaneously by routes state ux values under the most conclusive experimental of diVusion such as the shunt pathway, apart from slow transcelconditions possible. Using human SC separated b...
The in vivo effects of fatty acids on skin barrier function were assessed by measuring: (i) transepidermal water loss (TEWL), (ii) diffusion lag times for hexyl nicotinate (HN), and (iii) irritant skin response using laser Doppler velocimetry (LDV) in combination with visual scoring. Two classes of fatty acids have been investigated: straight-chain saturated fatty acids (SFA), having 6–12 carbon atoms, and unsaturated fatty acids (UFA): oleic, linoleic, α-linolenic and arachidonic acids. It has been reported that these acids can enhance the permeation of various compounds across the skin. After topical and occlusive application as a solution in propylene glycol (PG) for 3 h on the volar arm of human subjects, SFA only caused a slight irritation and increase in TEWL. The diffusion lag times of HN were reduced by the application SFA to the same extent as and not more than by the application of the pure solvent PG. In contrast, the application of UFA caused a significant increase in TEWL and LDV (irritation) responses. The TEWL values after oleic acid application were higher than those observed for the other three acids, while the irritation potential of arachidonic acid was the highest among UFA. As with SFA, sites treated with UFA did not show significantly different lag times of HN diffusion from PC-treated sites. The data suggest that the degree of irritation and the degree of barrier modulation for fatty acids are not necessarily correlated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.