Relationship between quin2-determined cytosolic [Ca2+] and sweat secretion

1988 ◽  
Vol 254 (2) ◽  
pp. C310-C317 ◽  
Author(s):  
K. Sato ◽  
F. Sato
Keyword(s):  
Calcium Concentration ◽  
Gradient Centrifugation ◽  
Co2 Production ◽  
Sweat Glands ◽  
Secretory Cells ◽  
Sweat Secretion ◽  
Dose Dependent

Although both methacholine (MCh)- and A23187-induced sweat secretion are known to be strictly dependent on extracellular Ca2+, the role of intracellular calcium concentration ([Ca2+]i) in eccrine sweating has not been clarified. Partially purified eccrine secretory cells were prepared from 400 to 600 isolated secretory coils of monkey sweat glands by serial collagenase digestion and Percoll gradient centrifugation. The quin2 method was used for semiquantitative determination of [Ca2+]i, MCh increased [Ca2+]i in a dose-dependent, reversible, and pharmacologically specific manner (from the resting [Ca2+]i of 80-320 nM) but failed to increase [Ca2+]i in a Ca2+-free medium. A23187 (10(-7) M) increased [Ca2+]i to approximately 900 nM. Theophylline (TH), isoproterenol (ISO), and forskolin (FK) had no effect on the resting [Ca2+]i but, in combination, attenuated the effect of subsequently added MCh and A23187. A23187 at 10(-7) M failed to stimulate sweat secretion or CO2 production in vitro from the quin2-loaded intact isolated sweat glands and dispersed sweat secretory cells, respectively. The observed dissociation between the increase in [Ca2+] may suggest either that MCh stimulation induces some unknown excitatory signal in addition to a rise in [Ca2+] or that A23187-induced Ca2+ influx into the secretory cells is much lower in undissociated sweat glands.

Role of calcium in cholinergic and adrenergic mechanisms of eccrine sweat secretion

1981 ◽  
Vol 241 (3) ◽  
pp. C113-C120 ◽  
Author(s):  
K. Sato ◽  
F. Sato
Keyword(s):  
Sweat Rate ◽  
Sweat Glands ◽  
Hyperbolic Function ◽  
Ionophore A23187 ◽  
Secretory Rate ◽  
Sweat Secretion ◽  
Eccrine Sweat Glands ◽  
Eccrine Sweat

The role of Ca2+ in eccrine sweat secretion was studied using isolated cannulated monkey palm eccrine sweat glands in vitro. Removal of Ca2+ from the incubation medium promptly abolished sweat secretion induced by methacholine or phenylephrine. In contrast, isoproterenol-induced sweat secretion lasted from 40 to 220 min in a Ca2+-free medium. The methacholine-induced maximal sweat rate was a hyperbolic function of the Ca2+ concentration in the bath and reached a plateau at 1 mM Ca2+. Higher Ca2+ concentrations rather suppressed the secretory rate. The Ca2+ ionophore A23187, but not X537A, at 3 X 10(-6) M induced copious prolonged sweat secretion after a latent period of 10 min. A23187-induced sweat secretion was not inhibited by either atropine or propranolol. D 600 (methoxyverapamil) at 10(-3) M inhibited sweat secretion induced by methacholine or by isoproterenol, although the latter lasted longer than methacholine sweating (20 vs. 5 min) in the presence of D 600. The data support the notion that Ca2+ influx into the cell plays a crucial role in cholinergic and alpha-adrenergic sweating, whereas a partial supply of Ca2+ for isoproterenol-induced sweating is derived from an intracellular store.

An Optimized MTT Bioassay for Determination of Cytotoxicity of Fumonisins in Turkey Lymphocytes

1994 ◽  
Vol 77 (2) ◽  
pp. 512-516 ◽  
Author(s):  
Mary A Dombrink-Kurtzman ◽  
Glenn A Bennett ◽  
John L Richard
Keyword(s):  
Gradient Centrifugation ◽  
In Vitro Cytotoxicity ◽  
Tetrazolium Salt ◽  
Animal Testing ◽  
Cytotoxicity Assays ◽  
Cytoplasmic Vacuolization ◽  
Diphenyl Tetrazolium Bromide ◽  
Dose Dependent

Abstract In vitro cytotoxicity assays have been performed for detection and quantitation of fumonisins, as possible alternatives for whole animal testing. This study was undertaken to establish optimal in vitro conditions using turkey lymphocytes. Turkey lymphocytes were isolated from peripheral blood by Percoll gradient centrifugation. Cytotoxicity of fu-monisin B1 (FB1) and B2 (FB2) was determined by exposing lymphocytes to FB1 or FB2 at concentrations of 0.01–25 μg/mL for 24,48, or 72 h at 39°C. The MTT bioassay was used to measure cell viability and proliferation. In metabolically active cells, the tetrazolium salt, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide], was reduced to MTT formazan. Turkey lymphocytes that had been exposed in vitro to FB1 and FB2 for 48 and 72 h showed inhibition of cell proliferation that was dose-dependent. The 50% inhibitory dose for FB1 and FB2 was 0.4–5 μg/mL. Cells exposed to FB1 or FB2 exhibited high levels of cytoplasmic vacuolization and were unable to proliferate, whereas proliferation of control lymphocytes was observed at 48 and 72 h. FB2 was 3- to 4-fold more cytotoxic than FB1.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

Factors affecting in vitro and in vivo antioxidant effects. Experimental conditions and nature of oxidants determine antioxidant efficacy

2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki
Keyword(s):  
Biological Molecules ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Beneficial Effects ◽  
Multiple Oxidants ◽  
Antioxidant Effects

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.

scholarly journals Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Map Kinases ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Dual Action ◽  
Dose Dependent ◽  
Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

scholarly journals Role of Bradykinin Type 2 Receptors in Human Sweat Secretion: Translational Evidence Does Not Support a Functional Relationship

2021 ◽  
Vol 34 (3) ◽  
pp. 162-166
Author(s):  
Thad E. Wilson ◽  
Seetharam Narra ◽  
Kristen Metzler-Wilson ◽  
Artur Schneider ◽  
Kelsey A. Bullens ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Sweat Rate ◽  
Sweat Glands ◽  
Potential Therapeutic Target ◽  
Sweat Secretion ◽  
Hoe 140 ◽  
A Current

Bradykinin increases skin blood flow via a cGMP mechanism but its role in sweating in vivo is unclear. There is a current need to translate cell culture and nonhuman paw pad studies into in vivo human preparations to test for therapeutic viability for disorders affecting sweat glands. Protocol 1: physiological sweating was induced in 10 healthy subjects via perfusing warm (46–48°C) water through a tube-lined suit while bradykinin type 2 receptor (B2R) antagonist (HOE-140; 40 μM) and only the vehicle (lactated Ringer’s) were perfused intradermally via microdialysis. Heat stress increased sweat rate (HOE-140 = +0.79 ± 0.12 and vehicle = +0.64 ± 0.10 mg/cm<sup>2</sup>/min), but no differences were noted with B2R antagonism. Protocol 2: pharmacological sweating was induced in 6 healthy subjects via intradermally perfusing pilocarpine (1.67 mg/mL) followed by the same B2R antagonist approach. Pilocarpine increased sweating (HOE-140 = +0.38 ± 0.16 and vehicle = +0.32 ± 0.12 mg/cm<sup>2</sup>/min); again no differences were observed with B2R antagonism. Last, 5 additional subjects were recruited for various control experiments which identified that a functional dose of HOE-140 was utilized and it was not sudorific during normothermic conditions. These data indicate B2R antagonists do not modulate physiologically or pharmacologically induced eccrine secretion volumes. Thus, B2R agonist/antagonist development as a potential therapeutic target for hypo- and hyperhidrosis appears unwarranted.

Intracellular calcium levels in the Plasmodium berghei ookinete

Parasitology ◽  
2008 ◽  
Vol 135 (12) ◽  
pp. 1355-1362 ◽  
Author(s):  
I. SIDÉN-KIAMOS ◽  
C. LOUIS
Keyword(s):  
Intracellular Calcium ◽  
Plasmodium Berghei ◽  
Calcium Concentration ◽  
Insect Cells ◽  
Ionophore A23187 ◽  
Rodent Malaria Parasite ◽  
Calcium Indicators ◽  
Intracellular Ca

SUMMARYOokinetes are the motile and invasive stages of Plasmodium parasites in the mosquito host. Here we explore the role of intracellular Ca2+ in ookinete survival and motility as well as in the formation of oocysts in vitro in the rodent malaria parasite Plasmodium berghei. Treatment with the Ca2+ ionophore A23187 induced death of the parasite, an effect that could be prevented if the ookinetes were co-incubated with insect cells before incubation with the ionophore. Treatment with the intracellular calcium chelator BAPTA/AM resulted in increased formation of oocysts in vitro. Calcium imaging in the ookinete using fluorescent calcium indicators revealed that the purified ookinetes have an intracellular calcium concentration in the range of 100 nm. Intracellular calcium levels decreased substantially when the ookinetes were incubated with insect cells and their motility was concomitantly increased. Our results suggest a pleiotropic role for intracellular calcium in the ookinete.

scholarly journals Inhibition of Prostate Cancer DU-145 Cells Proliferation by Anthopleura anjunae Oligopeptide (YVPGP) via PI3K/AKT/mTOR Signaling Pathway

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 325 ◽  
Author(s):  
Xiaojuan Li ◽  
Yunping Tang ◽  
Fangmiao Yu ◽  
Yu Sun ◽  
Fangfang Huang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Signaling Pathway ◽  
Caspase 3 ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Nude Mouse Model ◽  
Dose Dependent

We investigated the antitumor mechanism of Anthopleura anjunae oligopeptide (AAP-H, YVPGP) in prostate cancer DU-145 cells in vitro and in vivo. Results indicated that AAP-H was nontoxic and exhibited antitumor activities. Cell cycle analysis indicated that AAP-H may arrest DU-145 cells in the S phase. The role of the phosphatidylinositol 3-kinase/protein kinase B/mammalian rapamycin target protein (PI3K/AKT/mTOR) signaling pathway in the antitumor mechanism of APP-H was investigated. Results showed that AAP-H treatment led to dose-dependent reduction in the levels of p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448), whereas t-AKT and t-PI3K levels remained unaltered compared to the untreated DU-145 cells. Inhibition of PI3K/AKT/mTOR signaling pathway in the DU-145 cells by employing inhibitor LY294002 (10 μM) or rapamycin (20 nM) effectively attenuated AAP-H-induced phosphorylation of AKT and mTOR. At the same time, inhibitor addition further elevated AAP-H-induced cleaved-caspase-3 levels. Furthermore, the effect of AAP-H on tumor growth and the role of the PI3K/AKT/mTOR signaling pathway in nude mouse model were also investigated. Immunohistochemical analysis showed that activated AKT, PI3K, and mTOR levels were reduced in DU-145 xenografts. Western blotting showed that AAP-H treatment resulted in dose-dependent reduction in p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448) levels, whereas t-AKT and t-PI3K levels remained unaltered. Similarly, Bcl-xL levels decreased, whereas that of Bax increased after AAP-H treatment. AAP-H also increased initiator (caspase 8 and 9) and executor caspase (caspase 3 and 7) levels. Therefore, the antitumor mechanism of APP-H on DU-145 cells may involve regulation of the PI3K/AKT/mTOR signaling pathway, which eventually promotes apoptosis via mitochondrial and death receptor pathways. Thus, the hydrophobic oligopeptide (YVPGP) can be developed as an adjuvant for the prevention or treatment of prostate cancer in the future.

High-resolution capillary electrophoresis for the determination of carbamylated albumin

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Julien Favresse ◽  
Joris Delanghe
Keyword(s):  
Separation Efficiency ◽  
Theoretical Plate ◽  
Clinical Routine ◽  
Negative Prognostic Factor ◽  
Symmetry Factor ◽  
Primary Amino ◽  
The Mean ◽  
Dose Dependent

Abstract Objectives Carbamylation is a non-enzymatic post-translational reaction of a primary amino group of a protein with isocyanate. The albumin carbamylation is a negative prognostic factor in chronic kidney disease (CKD) patients and induce charge difference implying an observed shift in electrophoretic mobility that can be measured through a symmetry factor (SF). Methods The Helena V8 and the Sebia Capillarys 2 systems were used for all experiments. The effect of in vitro carbamylation on the SF by spiking increasing concentrations of potassium isocyanate (KCNO) in serum of three healthy volunteers was investigated. Theoretical plate numbers (N) as a surrogate of separation efficiency were also calculated and correlations between SF and renal function biomarkers were performed on 284 patients. Results A dose-dependent impact of KCNO on the SF was observed for both methods with the Helena V8 being more sensitive. The mean N was significantly higher on the Helena V8 as compared to the Sebia Capillarys 2 (2,972 vs. 444.1, p<0.0001). The SF correlated significantly with eGFR (r=0.50, p<0.0001), creatinine (r=−0.31, p<0.0001) and urea (r=−0.34, p<0.0001) on the Helena V8. On the Sebia Capillarys 2, a significant correlation was only observed with eGFR (r=0.17, p=0.004). A better discrimination between CKD stages was also observed using the Helena V8. Conclusions Thanks to a higher mean N, the Helena V8 might offer new possibilities, including detection of carbamylated albumin through SF calculation. Further studies are still needed to confirm the interest of using this type of assays in clinical routine.

Developmental role of endogenous retinoids in the determination of morphallactic field in budding tunicates

Development ◽  
1993 ◽  
Vol 117 (3) ◽  
pp. 835-845 ◽  
Author(s):  
K. Kawamura ◽  
K. Hara ◽  
S. Fujiwara
Keyword(s):  
Retinoic Acid ◽  
Aldehyde Dehydrogenase ◽  
Ectopic Expression ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Proximal Extremity ◽  
Developmental Role

We have extracted retinoids from the budding tunicate Polyandrocarpa misakiensis and, using HPLC, identified some major peaks as cis-retinal, all-trans-retinal and all-trans-retinoic acid, of which cis-retinal was most abundant (~2 micromolar). In developing buds, the amount of cis-retinal was about one-fifth that of the adult animals. In those buds, aldehyde dehydrogenase, which could metabolize retinal in vitro, was expressed in epithelial cells and then in mesenchymal cells at the proximal extremity, that is, the future developmental field of the bud. Exogenous retinoic acid comparable to the endogenous level could induce an additional field at the distal end of the bud, resulting in a double monster. The induction always accompanied an ectopic expression of aldehyde dehydrogenase. The results of this work suggest that retinoic acid or related molecule(s) act as an endogenous trigger of morphallactic development of Polyandrocarpa buds.

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