The ventral pelvic skin of the tree frog Hyla japonica expresses two kinds of arginine vasotocin (AVT)-stimulated aquaporins (AQP-h2 and AQP-h3), which affect the capacity of the frog's skin to absorb water. As such, it can be used as a model system for analyzing the molecular mechanisms of water permeability. We investigated AQP dynamics and water permeability in the pelvic skin of H. japonica...

Properties of the shunt pathway (a pathway in parallel to the Na transport system) in frog skin have been examined. The permeability of this shunt to urea increases markedly when the skin is depolarized to -100 mv (inside negative) but hyperpolarization to +100 mv produces no change in urea permeability compared to short-circuit conditions. The permeability increase at depolarizing potentials i...

Improving prediction of the skin permeability coefficient is a difficult problem, and an important issue with the increasing use of skin patches as a means of drug delivery. In this work, we apply Gaussian Processes (GPs) with five different covariance functions to predict the permeability coefficients of human, pig, rodent and silastic membranes. We obtain a considerable improvement over quant...

Aqueous extracts of Acalypha langinia, Buddleia scordioides, Hylocereus undatus, Tecoma stans showed protective activity against the increased (both chloroform and histamine) skin vascular permeability in rabbits. The protective effect, measured as the reduction in leakage of Evans blue, were 90.2, 37.3, 43.5 and 69.3% respectively a dose of 250 mg/kg. Astianthus viminalis, showed only a 12.6% ...

Recent advances in transdermal drug delivery utilizing low-frequency sonophoresis (LFS) and sodium lauryl sulfate (SLS) have revealed that skin permeability enhancement is not homogenous across the skin surface. Instead, highly perturbed skin regions, known as localized transport regions (LTRs), exist. Despite these findings, little research has been conducted to identify intrinsic properties a...

Topical 5-fluorouracil (5-FU) is approved for the treatment of superficial basal cell carcinoma and actinic keratosis. However, 5-FU suffers from poor skin permeation. Microneedles have been successfully applied to improve the skin permeability of small and large molecules, and even nanoparticles, by creating micron-sized pores in the stratum corneum layer of the skin. In this report, the feasi...

MISTRETTA, CHARLOTTE M. Permeability of tongue epithelium and its relation to taste. Am. J. Physiol. 220(5) : 1162-l 167. 197 1 .-The permeability of rat tongue epithelium was investigated to provide information on the accessibility of free lingual nerve endings to chemical stimuli. Permeability of rat belly skin was also studied. Dorsal tongue epithelium was removed after subepithelial injecti...

Blood vessel endothelium forms a semi-permeable barrier and its permeability controls the traffics of plasma contents. Here we report an intravital evaluation system for vascular permeability in mice using two-photon microscopy. We used various sizes of fluorescein-conjugated dextran as a tracer and its efflux was quantified by measuring the changes of fluorescent intensity both on the blood ve...

The regulation of water loss through the skin is a poorly understood but crucial process in maintaining terrestrial life-forms. In mammalian skin, the outermost layer, called the stratum corneum (SC), is rate-limiting to water loss. We have evaluated temperature-dependent changes in water vapor permeability and infrared spectra of porcine SC. In particular, we have analyzed the infrared absorpt...

Topical trans-dermal delivery of drugs has proven to be a promising route for treatment of many dermatological diseases. The aim of this study is to monitor and quantify the permeability rate of glucose solutions in rhesus monkey skin noninvasively in vivo as a primate model for drug diffusion. A time-domain Optical Coherence Tomography (OCT) system was used to image the diffusion of glucose in...