Epidermal Concentration Research Articles

Na+ is shifted from the extracellular to the intracellular compartment and is not inactivated by glycosaminoglycans during high salt conditions in rats.

Recently, studies have emerged suggesting that the skin plays a role as major Na+ reservoir via regulation of the content of glycosaminoglycans and osmotic gradients. We investigated whether there were electrolyte gradients in skin and where Na+ could be stored to be inactivated from a fluid balance viewpoint. Na+ accumulation was induced in rats by a high salt diet (HSD) (8% NaCl and 1% saline to drink) or by implantation of a deoxycorticosterone acetate (DOCA) tablet (1% saline to drink) using rats on a low salt diet (LSD) (0.1% NaCl) on tap water as control. Na+ and K+ were assessed by ion chromatography in tissue eluates, and the extracellular volume by equilibration of 51Cr‐EDTA. By tangential sectioning of the skin, we found a low Na+ content and extracellular volume in epidermis, both parameters rising by ∼30% and 100%, respectively, in LSD and even more in HSD and DOCA when entering dermis. We found evidence for an extracellular Na+ gradient from epidermis to dermis shown by an estimated concentration in epidermis ∼2 and 4–5 times that of dermis in HSD and DOCA‐salt. There was intracellular storage of Na+ in skin, muscle, and myocardium without a concomitant increase in hydration. Our data suggest that there is a hydration‐dependent high interstitial fluid Na+ concentration that will contribute to the skin barrier and thus be a mechanism for limiting water loss. Salt stress results in intracellular storage of Na+ in exchange with K+ in skeletal muscle and myocardium that may have electromechanical consequences.Key points Studies have suggested that Na+ can be retained or removed without commensurate water retention or loss, and that the skin plays a role as major Na+ reservoir via regulation of the content of glycosaminoglycans and osmotic gradients.In the present study, we investigated whether there were electrolyte gradients in skin and where Na+ could be stored to be inactivated from a fluid balance viewpoint.We used two common models for salt‐sensitive hypertension: high salt and a deoxycorticosterone salt diet.We found a hydration‐dependent high interstitial fluid Na+ concentration that will contribute to the skin barrier and thus be a mechanism for limiting water loss.There was intracellular Na+ storage in muscle and myocardium without a concomitant increase in hydration, comprising storage that may have electromechanical consequences in salt stress.

Adaption of body zinc pools in weaned piglets challenged with subclinical zinc deficiency.

The effects of subclinical Zn deficiency on depletion and redistribution of body Zn were studied in weaned piglets. Forty-eight weaned piglets (German-Large-White×Land-Race×Piétrain; 50 % female, 50 % male-castrated; body weight 8·5 (sd 0·27) kg) were fed restrictively (450 g/d) a basal maize-soyabean meal-based diet supplemented with varying amounts of ZnSO4.7H2O (analysed dietary Zn: 28·1, 33·6, 38·8, 42·7, 47·5, 58·2, 67·8, 88·0 mg/kg diet) for an experimental period of 8 d. Analyses comprised Zn concentrations in soft tissues. Statistical analyses included regression models and k-means cluster analysis. Jejunum and kidney Zn correlated positively with dietary Zn (P<0·05). Other Zn pools responded in a non-linear fashion by declining (colon, epidermis, spleen) or increasing (mesenteric lymph follicles, thymus, skeletal muscle) below 63·6, 48·0, 47·5, 68·0, 43·0 and 53·1 mg Zn/kg diet, respectively (P<0·01). Above these thresholds, Zn concentrations in epidermis, mesenteric lymph follicles and skeletal muscle plateaued (P<0·0001), whereas they exhibited a decrease in colon and thymus (P<0·01) as well as a numerical increase in spleen. Clustering by dietary Zn concentration indicated clusters of varying Zn supply status and pathophysiological status. Clustering by biological matrices revealed a discrimination between storage, transport and excretion media as well as soft tissues. Taken together, novel response patterns indicated compensation reactions in tissues that are essential for the acute survival of growing animals (heart, skeletal muscle, immune tissues). Furthermore, this is to our knowledge the first study that mapped the gross Zn requirement by clustering tissue Zn concentrations between treatment groups.

Seasonal differences in trace element concentrations and distribution in Spartina alterniflora root tissue

The present study uses nanometer-scale synchrotron X-ray nanofluorescence to investigate season differences in concentrations and distributions of major (Ca, K, S and P) and trace elements (As, Cr, Cu, Fe and Zn) in the root system of Spartina alterniflora collected from Jamaica Bay, New York, in April and September 2015. The root samples were cross-sectioned at a thickness of 10 μm. Selected areas in the root epidermis and endodermis were mapped with a sampling resolution of 100 and 200 nm, varying with the mapping areas. The results indicate that trace element concentrations in the epidermis and endodermis vary among the elements measured, possibly because of their different chemical properties or their ability to act as micronutrients for the plants. Elemental concentrations (As, Ca, Cr, Cu, Fe, K, P, S and Zn) within each individual root sample and between the root samples collected during two different seasons are both significantly different (p < 0.01). Furthermore, this study indicates that the nonessential elements (As and Cr) are significantly correlated (p < 0.01) with Fe, with high concentrations in the root epidermis, while others are not, implying that Fe may be a barrier to nonessential element transport in the root system. Hierarchy cluster analysis shows two distinct groups, one including As, Cr and Fe and the other the rest of the elements measured. Factor analysis also indicates that the processes and mechanisms controlling element transport in the root system can be different between the nutrient and nonessential elements.

Correlation of trace element concentrations between epidermis and internal organ tissues in Indo-Pacific humpback dolphins (Sousa chinensis)

Trace element accumulation in the epidermis of cetaceans has been less studied. This study explored the feasibility of using epidermis as a surrogate tissue to evaluate internal contaminant burdens in Indo-Pacific humpback dolphin (Sousa chinensis). Eleven trace elements were analyzed in the epidermis, muscle and liver tissues from 46 individuals of dolphins stranded along the Pearl River Estuary (PRE) coast between 2007 and 2013. Trace elemental concentrations varied among the three tissues, generally with the highest concentrations found in liver tissues and lowest in the epidermis (except Zn, As, and Pb). Zn concentration in the epidermis was the highest among all tissues, indicating that Zn could be an important element for the epidermis physiology. High concentrations of Hg and Cr in liver were likely due to an excessive intake by dolphins which consumed high Hg and Cr contaminated fishes in the PRE. Hg concentrations in epidermis and muscle tissues were significantly higher in the females than in males. Concentrations of V and Pb in liver, Se and Cd in both muscle and liver, and As and Hg in all tissue samples showed significantly positive relationships with body length. Hepatic Cu concentrations were significantly negatively correlated with the body length. Hg and As concentrations in epidermis showed significantly positive correlations with those in liver tissues. Thus this study proposed that epidermis could be used as a non-invasive monitoring tissue to evaluate Hg and As bioaccumulation in internal tissues of Indo-Pacific humpback dolphins populations.

Influence of laser wavelength on the thermal responses of port wine stain lesions in light, moderate and heavy pigmented skin

Abstract Pulsed dye laser (PDL) in visible band (e.g. 585 or 595 nm) together with cryogen spray cooling has become the golden standard for treatment of vascular malformation such as port wine stain (PWS). However, due to the limited energy penetration depth of the PDL, deeply buried blood vessels are likely to survive from the laser irradiation. Nd:YAG laser in near infrared (1064 nm) has great potential in the laser treatment of PWS due to its deeper penetration depth. In this study, the influence of laser wavelength in treating PWS lesions with various melanin concentrations in epidermis was theoretically investigated by a two-temperature model following the local thermal non-equilibrium theory of porous media. The results showed that deeply buried blood vessels can be coagulated by dual-wavelength laser combing 585 or 595 nm with 1064 nm laser. Furthermore, the therapeutic results by dual-wavelength laser were highly related to the melanin concentration in epidermis. In the light and moderate pigmented skin, the 595/1064 nm dual-wavelength laser showed better treatment effect in treating PWS with deeply-buried blood vessels than of 585/1064 nm dual-wavelength laser. For a high pigmented skin, the 585/1064 nm dual-wavelength laser showed better treatment effect than 595/1064 nm dual-wavelength laser.

Effect of ultrasound and heat on percutaneous absorption of l-ascorbic acid: human in vitro studies on Franz cell and Petri dish systems.

Percutaneous absorption of l-ascorbic acid (LAA) is limited due to its high hydrophilicity and low stability. Here, we investigated the effect of post-dosing sonophoresis (329 kHz, 20 mW cm-2 ) and heat (36°C) on transdermal delivery of LAA. Ultrasound/heat, heat and control treatments were applied on skin surface for 2 and 5 min after topical application of C14-labelled LAA aqueous solution. After 15 min post-exposure, radioactivity was measured in tape-striped stratum corneum (TS-SC), epidermis, dermis and receptor fluid. As Franz diffusion cell model may have different acoustic response than in vivo human tissues, a novel Petri dish model was developed and compared with Franz cell model on the effects of ultrasound/heat treatment on the skin permeability. Five-min ultrasound/heat treatment significantly accelerated skin absorption/penetration of LAA; 2-min treatment showed no enhancement effect on Franz diffusion cell model at the end of experiment. The use of Petri dish model significantly increased LAA concentrations in epidermis after 5 min of ultrasound/heat treatment, compared to the results of Franz cell model. Combination of ultrasound (329 kHz, 20 mW cm-2 ) and heat (36°C) significantly enhanced LAA transdermal penetration, when the time of treatment was sufficient (5 min). As Petri dish model was designed to simulate acoustic respond of dense human tissue to ultrasound, the difference between Franz cell and Petri dish models suggests that the enhancement effect of ultrasound/heat on skin penetration in vivo may be greater than that determined on in vitro Franz cell model.

Development of ciclopirox olamine topical formulations: evaluation of drug release, penetration and cutaneous retention

With the aim of reducing system absorption and consequently, the side effects, and simultaneously select a penetration enhancing, three topical formulations with 0.5% ciclopirox olamine (CO) and 15% of propylene glycol (PG), ethoxydiglycol or oleic acid were developed and evaluated regarding the skin penetration and cutaneous retention of the drug using Franz diffusion cells. Release experiments were performed through synthetic membrane while dermatomed pig ear skin was used to evaluate CO skin penetration and skin retention. Retention studies were carried out applying tape stripping method and dosing CO in stratum corneum and in epidermis and dermis. A HPLC method was validated for quantifying CO. All formulations tested with synthetic membrane presented no retention of the drug. Permeation data suggested that there was no systemic absorption of ciclopirox olamine from the studied formulations, even when the skin penetration enhancers were applied. Higher concentrations of the drug were found in the stratum corneum (SC) and also in epidermis and dermis, for all of the developed formulations. The addition of enhancers improved the penetration and cutaneous retention of CO, and propylene glycol promoted higher concentrations in epidermis and dermis, probably because its cumulative effect on the skin and by an efficient solvent power.

Trans- and cis-DNA adduct concentration in epidermis from mouse and rat skin treated ex vivo with benzo[a]pyrene diol epoxide and its corresponding chlorohydrin

Benzo[a]pyrene diol epoxide, a metabolite of benzo[a]pyrene (BaP), and chlorohydrin, the reaction product of chloride and the epoxide, form in vitro the same trans- and cis-stereoisomeric DNA adducts, but in different proportions. In this study, we asked whether the DNA adduct concentration can be kept the same by applying the appropriate dose of (±)-7 r,8 t-dihydroxy-9 t,10 t-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene ( anti-BPDE)and (±)-7 r,8 t,9 t-trihydroxy-10 c-chloro-7,8,9,10-tetrahydrobenzo[a]pyrene ( trans-BPDCH) to rodent skin and whether the DNA adducts formed differ only in their trans- and cis-stereoisomerism. Skin from C57Bl6 mice, spontaneous hypertension rats (SHR) and Sprague-Dawley (SD) rats was treated ex vivo immediately after the death of the animals with anti-BPDE and its corresponding bay region chlorohydrin trans-BPDCH and the epidermis was analyzed for DNA adducts 1 h after the application. We found that adduct formation at the exocyclic amino groups of deoxyguanosine and deoxyadenosine in epidermal DNA followed a linear dose–response within 6–100 nmol/cm 2 with both chemicals. In order to achieve the same adduct concentration in mouse, spontaneous hypertension rat (SHR), and Sprague-Dawley (SD) rat skin, respectively, a 37-, 23- and 10-fold lower dose of anti-BPDE than of trans-BPDCH had to be applied. The order of 2′-deoxyguanosine (dGuo) adduct concentration with anti-BPDE was similar to what has been reported, but the order with trans-BPDCH was (+)- cis-BPDE-N 2-dGuo adduct>(+)- trans-BPDE-N 2-dGuo=(−)- trans-BPDE-N 2-dGuo>(−)- cis-BPDE-N 2-dGuo in mouse skin. Irrespective of species or strain, a significantly higher proportion of cis-adducts was obtained after treatment with trans-BPDCH than after treatment with anti-BPDE. Therefore, DNA adduct concentration can be kept the same by applying the appropriate dose of anti-BPDE and trans-BPDCH to rodent skin and the DNA adducts formed differ only in their trans- and cis-stereoisomerism.

Free sphingosines in oral epithelium

Free sphinogosines, intermediates in the biosynthesis of ceramides and inhibitors of protein kinase C, have been found to be present in significant concentrations in epidermis and oral epithelia of the pig (Sus scrofa). Concentrations of sphingosines were higher in the outer portion of epidermis (4.4 mg/g), palatal epithelium (3.9 mg/g) and buccal epithelium (0.7 mg/g) compared to the inner portion of the epithelia (1.0, 0.9 and 0.4 mg/g, respectively). Free sphingosines may provide antimicrobial activity at the epithelial surfaces, and the sphingosine gradient may modulate epithelial differentiation.

Programmed expression of cholesterol sulfotransferase and transglutaminase during epidermal differentiation of murine skin development

To clarify the role of cholesterol sulfate (CS) in the process of epidermal differentiation in vivo, we investigated the concentration of CS and the specific activities of cholesterol sulfotransferase (CST), cholesterol sulfate sulfatase (CS sulfatase) and epidermal transglutaminase (ETG) in murine skin in the pre- and postnatal periods. In the skin at day 14 of gestation, CS was not detected with TLC and the specific activities of all the enzymes were low. However, concomitant with the formation of the multilayered structure of the epidermis (at day 16), the specific activities of CST steeply increased. Although the insoluble CS sulfatase in the microsomal fraction remained at a relatively constant level, the soluble CST in the cytosol fraction showed a 6-fold increase from day 14 to day 16, and the activity decreased continuously in the following period, reaching one forty-sixth of the maximum level at 4-months-old mice. Reflected by the increase in activity, CS was detected in fetal skin at day 15, and the concentration in epidermis significantly increased during the gestation period, reaching maximum level at day 17. Furthermore, the changes in the concentration of cholesterol sulfate were identical with those of N-( O-linoleoyl)- ω-hydroxy fatty acyl sphingosine and its glucosyi derivative in the epidermis. On the other hand, the specific activity of ETG increased after birth. Thus, the activation of CST and ETG was shown to occur separately in association with the formation of the multilayered structure and thickening of the stratum corneum, respectively.

Synthetic Retinoids Affect Differently the Epidermal Synthesis of 3,4-Didehydroretinol

For unknown reasons, the epidermal concentrations of retinol and its metabolite 3,4-didehydroretinol become characteristically changed during treatment with certain synthetic retinoids. In the present study we investigated [3H]retinol uptake and conversion to 3,4-[3H]didehydroretinol in cultured human skin exposed to six different retinoids. The tissue accumulation of [3H]retinol increased by 50-130% following addition of 1.3 microM of all-trans-retinoic acid, 13-cis-retinoic acid, or 3,4-didehydroretinoic acid (putative metabolites of retinol), and by 13-55% after addition of acitretin, arotenoid Ro 13-7410, or 4-(N-hydroxyphenyl)retinamide. The formation of 3,4-[3H]didehydroretinol was markedly inhibited (minus 80-90%) by the three putative retinol metabolites, moderately inhibited (minus 60-70%) by the aromatic retinoic acid analogues acitretin and arotinoid, and only slightly inhibited (minus 25%) by 4-(N-hydroxyphenyl)retinamide. Addition of citral and ketoconazole, substances known to interfere with the oxidative metabolism of vitamin A, diminished the formation of 3,4-didehydroretinol by 70 and 95%, respectively, but only marginally affected the retinol values. We conclude that the increase in retinol and marked reduction in 3,4-didehydroretinol concentrations in epidermis especially during treatment with 13-cis-retinoic acid are most likely due to diminished conversion of retinol to 3,4-didehydroretinol, but whether or not this reflects feedback inhibition of retinol metabolism or direct inhibition of a specific enzyme remains to be established. Nonetheless, in vitro analysis of 3,4-didehydroretinol biosynthesis appears to be a sensitive means for screening compounds for their ability to interfere with the cutaneous vitamin A metabolism.

Early Metabolic Changes in Rat Epidermis and Dermis Following Cutaneous Application of Irritant Doses of Tributyltin

Metabolic changes produced in rat skin by tributyltin have been determined with the aim of identifying some of the early events which may be associated with the irritant response of this compound. When the skin irritant tributyltin (TBT) was applied to rat dorsal skin as a single cutaneous dose of 67 nmoles of TBT/sp. cm, steady state levels of 0.44 nmoles/mg dry weight were attained in the viable epidermis by 1 hr. Calculations indicate that depletion of the applied dose and consequent reduction of the concentration in the viable epidermis occurred after 5–6 hr. This dose of TBT significantly reduced the oxygen consumption of epidermal slices by 1 hr. There were minimal pathological changes at this times. Maximum inhibition of oxygen consumption occurred by 8 hr (epidermal and dermal slices inhibited by 49% and 46% respectively) by which time focal epidermal and dermal separation had occurred and numerous inflammatory cells were present. Oxygen consumption returned to normal within 48 hr. The inhibition was accompanied by a concomitant reduction in ATP concentration in the epidermis with values reduced by 63% at 12 hr. ATP remained at this value for 20 hr, returning to normal by 48 hr. Lactate concentration in full thickness skin increased by 89% within 2 hr of application of tributyltin and remained elevated for up to 48 hr. The earliest detectable reductions in oxygen consumption and ATP concentration coincided with the time when the tributyltin content of the epidermis was maximal and preceded any necrotic changes. The recovery phase coincided with reduction of tributyltin concentration. It is concluded that the early toxic action of tributyltin in rat skin involves inhibition of oxidative metabolism. The resulting perturbations may result in cellular injury or dearth and these changes may be involved in production of the altered skin.

The Quantitative Distribution Of Gold In Skin During Chrysotherapy

Gold concentrations in epidermis, dermis, and whole skin were measured by neutron activation analysis after formation of suction bullae in 8 patients who had received protracted cyrysotherapy. Epidermis contained 3% (median) of the gold content of whole skin. A direct correlation between cumulative gold dose and skin gold level was noted. These findings suggest that apparent gold concentrations in skin are influenced by the depth of the biopsy, that keratinous tissues have little affinity for gold, and that the gold storage capability of skin is not saturated by large cumulative doses of gold. The beneficial effect of gold in pemphigus may not be mediated at the site of blister formation.

Na + pool and Na + concentration in epidermis of frog skin

I. Estimations of intracellular [Na +] c in epithelial cells of non-short-circuited skins of Rana pipiens in sulfate Ringer's were made at varying [Na +] 0 by two indirect methods. (a) Intracellular Na + content (μequiv/cm 2) was determined by the “Na +-pool method”. From this and estimations of total cellular and extracellular volume an average value for [Na +] e was calculated. (b) [Na +] e was determined by using a modified Nernst equation, assuming Na + permselectivity for the “outer border” of skin. Both methods yielded identical values for [Na +] e which varied in the same manner with [Na +] o . 2. From variations of [Na +] 8 [Na +] in the subcorneal space) and [Na +] e with changing [Na +] o , E 00 (potential difference across outer border) was calculated and the results compared to the experimentally found change of 35 mV for a io-fold change in [Na +] 0 . The calculation s based on [Na +] s and [Na +] e gave the correct slope, but the absolute potential differences (PD) were too low when compared to known measurements of the intracellular PD values. 3. From this discrepancy it is suggested that [Na +] e in the cells of the “first reacting cell layer” is lower, and [Na +] e in the remaining cells is higher than [Na +] e . This is illustrated by a sample calculation. Values for [Na +] e , first reacting cell layer, are 3–13 mM for [Na −] 0 = 7−110mM . This supports the hypothesis of passive entry of Na + into the epidermis. By computer simulation it is shown that a model can be constructed that maintains in a steady state such [Na +] gradients and yields flux characteristics in agreement with typical laboratory observations.

Chemical basis for the [H+] gradient across frog skin.

ARTICLESChemical basis for the [H+] gradient across frog skinRT Friedman, NS LaPrade, RM Aiyawar, and EG HufRT Friedman, NS LaPrade, RM Aiyawar, and EG HufPublished Online:01 May 1967https://doi.org/10.1152/ajplegacy.1967.212.5.962MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByA novel subtilisin-like serine protease of Batrachochytrium dendrobatidis is induced by thyroid hormone and degrades antimicrobial peptidesFungal Biology, Vol. 117, No. 6Seasonal variations in integumental glycoconjugates ofRana rugosaThe Anatomical Record, Vol. 249, No. 1Cutaneous and renal responses to intravascular infusions of HCl and NH4Cl in the bullfrog (Rana catesbiana)Comparative Biochemistry and Physiology Part A: Physiology, Vol. 84, No. 1Studies on the attachment response ofIsthmiophora melis cercariae (Trematoda: Echinostomatidae)Zeitschrift f�r Parasitenkunde Parasitology Research, Vol. 71, No. 4The epithelium of Rana pipiens excretes H+ and NH+4 in acidosis and HCO−13 in alkalosisComparative Biochemistry and Physiology Part A: Physiology, Vol. 68, No. 3Excretion of K+ by frog skin with rate varying with K+ loadComparative Biochemistry and Physiology Part A: Physiology, Vol. 69, No. 1Transport Across Amphibian SkinIonic exchanges in isolated and open-circuited toad skinThe Journal of Membrane Biology, Vol. 35, No. 1Numerical simulation of Na* washout rates in whole frog skinAnnals of Biomedical Engineering, Vol. 5, No. 2Some features of hydrogen (ion) secretion by the frog skinBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 406, No. 1The excretion of hydrogen ion by the isolated amphibian skin: Effects of antidiuretic hormone and amilorideBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 382, No. 3Chloride transport in isolated skin of Rana esculentaPfl�gers Archiv European Journal of Physiology, Vol. 355, No. 2Flask cells and epidermal dynamics in frog skin20 August 2009 | Journal of Zoology, Vol. 175, No. 1Conductance Recording of Ionic Outflow from Frog Skin Glands during Nerve StimulationActa Physiologica Scandinavica, Vol. 93, No. 1Analyse der invasionsmechanismen der cercarie von Diplostomum spathaceum—II. Chemische invasionsstimuliInternational Journal for Parasitology, Vol. 4, No. 3GAS EXCHANGES AND BLOOD GAS CONCENTRATIONS IN THE FORG RANA RIDIBUNDA1 June 1974 | Journal of Experimental Biology, Vol. 60, No. 3Adrenoceptors and salt and water movement in epitheliaNaunyn-Schmiedeberg's Archives of Pharmacology, Vol. 281, No. 3Role of Na+ and anions in the triple response of isolated frog skin to norepinephrineBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 323, No. 2Carbonic anhydrase activity in Rana pipiens skin: biochemical and histochemical analysisHistochemie, Vol. 36, No. 1Na+ pool and Na+ concentration in epidermis of frog skinBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 291, No. 2CARBONIC ANHYDRASE:ISOENZYMES. PROPERTIES. DISTRIBUTION. AND FUNCTIONAL SIGNIFICANCEBiological Reviews, Vol. 47, No. 4β-Adrenergic stimulation of frog skin mucous glands: Non-specific inhibition by adrenergic blocking agentsComparative and General Pharmacology, Vol. 2, No. 7Movement of CO2 and HCO3 across isolated frog skinBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 225, No. 1The production of a hydrogen ion gradient across the isolated frog skin quantitative aspects and the effect of acetazolamideBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 203, No. 3Histochemistry of mucus in the skin of the frog,Rana pipiensThe Anatomical Record, Vol. 166, No. 4The action of beta adrenergic site stimulating, catecholamines on isolated frog skinBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 203, No. 1Effect of Secretin on Human Rectal Mucosa in vivo1 February 1968 | Nature, Vol. 217, No. 5127Effects of NH4+-ions on acid-base properties and ion movements in isolated frog skinComparative Biochemistry and Physiology, Vol. 23, No. 3Electrolytes in frog skin secretionsComparative Biochemistry and Physiology, Vol. 23, No. 1 More from this issue > Volume 212Issue 5May 1967Pages 962-972 Copyright & PermissionsCopyright © 1967 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1967.212.5.962PubMed6023881History Published online 1 May 1967 Published in print 1 May 1967 Metrics

Absorption of Antimalarial Drugs in Human Skin: Spectroscopic and Chemical Analysis in Epidermis and Corium

The concentration of antimalarials in the human skin, particularly in regard to the relative concentrations in epidermis and corium, has not to our knowledge been reported. Similarly we have seen no documentation on the effect of antimalarials in modifying the ultraviolet light absorption of separated epidermis and corium.