Active vasodilatation (AVD) in human, non-glabrous skin depends on functional cholinergic fibres but not on acetylcholine (ACh). We tested whether AVD is a redundant system in which ACh and vasoactive intestinal polypeptide (VIP) are co-released from cholinergic nerves. (1) We administered VIP by intradermal microdialysis to four discrete areas of skin in the presence of different levels of the VIP receptor antagonist, VIP(10-28), also delivered by microdialysis. Skin blood flow (SkBF) was continuously monitored by laser Doppler flowmetry (LDF). Mean arterial pressure (MAP) was measured non-invasively and cutaneous vascular conductance (CVC) calculated as LDF/MAP. Subjects were supine and wore water-perfused suits to control whole-body skin temperature (Tsk) at 34 degrees C. Concentrations of 54 microM, 107 microM, or 214 microM VIP(10-28) were perfused via intradermal microdialysis at 2 microl min-1 for approximately 1 h. Then 7.5 microM VIP was added to the perfusate containing VIP(10-28) at the three concentrations or Ringer solution and perfusion was continued for 45-60 min. At the control site, this level of VIP caused approximately the vasodilatation typical of heat stress. All VIP(10-28)-treated sites displayed an attenuated dilatation in response to the VIP. The greatest attenuation was observed at the site that received 214 microM VIP(10-28) (P < 0.01). (2) We used 214 microM VIP(10-28) alone and with the iontophoretically administered muscarinic receptor antagonist atropine (400 microA cm-2, 45 s, 10 mM) in heated subjects to test the roles of VIP and ACh in AVD. Ringer solution and 214 microM VIP(10-28) were each perfused at two sites, one of which in each case was pretreated with atropine. After 1 h of VIP(10-28) treatment, individuals underwent 45-60 min of whole-body heating (Tsk to 38.5 degrees C). VIP(10-28), alone or in combination with atropine, attenuated the increase in CVC during heat stress, suggesting an important role for VIP in AVD.
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http://dx.doi.org/10.1113/jphysiol.2003.042135 | DOI Listing |
Eye Sci
September 2013
Department of Ophthalmology, Chinese PLA General Hospital, Beijing 100853, China.
Purpose: To analyze the consistency between preoperatively estimated and postoperatively measured total spherical aberration and to evaluate the feasibility of personalized selection of an aspherical intraocular lens (IOL) based on the corneal spherical aberration measured by the Scheimpflug photography system (Pentacam).
Methods: A total of 47 patients (82 eyes) with age-related cataract received a comprehensive ophthalmologic examination. Corneal spherical aberration was measured by using the Scheimpflug photography system.
Huan Jing Ke Xue
August 2013
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
In order to investigate the characteristic of organic carbon (OC) and elemental carbon (EC) in particles on the top of coke oven and in the plant area, the particle matter samples of five size fraction including < or = 1.4 microm, 1.4-2.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
March 2013
School of Chemical Engineering, Yeungnam University, 214-1 Dae-dong, Gyeongsan 712-749, Republic of Korea.
Polycrystalline Cu(2-x)Se thin films for solar cell application were deposited by a solution-based continuous flow reactor (CFR) process. In order to study the influence of reaction time on the physical, structural, and optical properties of the Cu(2-x)Se thin films, the deposition time for impinging varied from 2 min to 15 min. Based on X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectrophotometry, the optimum time to deposit the Cu(2-x)Se thin films using the CFR process was 10 min.
View Article and Find Full Text PDFSe Pu
January 2013
College of Sciences, Agricultural University of Hebei, Baoding 071001, China.
A novel method for the separation and determination of o-phthalaldehyde (OPA), p-chloro-m-xylenol (PCMX) and triclosan in daily chemicals and compound chemical disinfectants in a single run by micellar electrokinetic chromatography (MEKC) was established. The factors such as the buffer concentration and pH, the concentration of sodium dodecyl sulfate (SDS), and the sample buffer, were investigated in detail. The analysis was carried out using a 50 microm uncoated capillary of 40.
View Article and Find Full Text PDFBenzalkonium chloride (BAC) is a mixture of alkyl substituted benzyl dimethylammonium chloride homologs (C12-BAC, C14-BAC and C16-BAC). Chlorhexidine acetate is a widely used effective component in compound chemical disinfectants. A method for the simultaneous determination of chlorhexidine acetate and benzalkonium chloride in compound chemical disinfectants by capillary electrophoresis (CE) was established.
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