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- Lundquist, Ingmar, et al.
(författare)
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Monoamines in pancreatic islets of guinea pig, hamster, rat, and mouse determined by high performance liquid chromatography
- 1989
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Ingår i: Pancreas. - 0885-3177. ; 4:6, s. 662-667
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies on the occurrence of catecholamines and serotonin in pancreatic islets using various histochemical and chemical methods have given widely different results. We therefore performed a comparative analysis of these amines in whole pancreas and islet tissue from hamster, guinea pig, rat, and mouse by the use of high performance liquid chromatography. Whole pancreas of guinea pig, hamster, and rat had a norepinephrine concentration of approximately 1.1 [mu]mol/kg of pancreatic wet weight. The mouse pancreas had less than one-half of that concentration. Epinephrine and dopamine concentrations were on the order of 0.02 [mu]mol/kg of pancreatic wet weight in all four species. The serotonin concentration was 2.1 [mu]mol/kg of pancreatic wet weight in the guinea pig pancreas and approximately 0.2 [mu]mol/kg in the other three species studied. The catecholamine concentrations were much higher in the pancreatic islets than in the exocrine pancreas. Thus, the norepinephrine concentration was approximately 35 [mu]mol/kg of islet wet weight in hamster islets and 5-10 [mu]mol/kg in rat, guinea pig, and mouse islets. The epinephrine concentration in islet tissue ranged between 1 and 7 [mu]mol/kg of islet wet weight and the dopamine concentration between 0.5 and 4 [mu]mol/kg except for guinea pig islets (12 [mu]mol/kg). The islet tissue in the mouse, rat, and guinea pig contained disproportionately more epinephrine and dopamine relative to norepinephrine than did the exocrine pancreas. Chemical sympathectomy (6- hydroxydopamine treatment) in the mouse reduced the norepinephrine and epinephrine concentrations in islet tissue to nondetectable levels, whereas the dopamine concentration was essentially unchanged, thus suggesting an extraneuronal source of this amine in addition to its occurrence in adrenergic nerves. The islets of hamster, rat, and mouse contained no serotonin, whereas guinea pig islets contained approximately 275 [mu]mol/kg of islet wet weight. We conclude that, although species differences exist, the pancreatic islets have markedly higher levels of catecholamines than the exocrine pancreas, and that serotonin occurs in the exocrine pancreas of all four species studied but in the endocrine pancreas only in the guinea pig.
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| 2. |
- Andersson, Anders, et al.
(författare)
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The epidermal indeterminate cell- a special cell type?
- 1981
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Ingår i: Acta dermato-venereologica. Supplementum. - 0365-8341. ; 99, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- Electron microscopy of normal human epidermiscomprising very large series of sections in combination withtilting of the sections has revealed that all "indeterminatecells" carry the specific markers of either melanocytes orLangerhans cells. The term "indeterminate cells" can thusbe abandoned. In addition, it is suggested that an epidermaldendritic cell lacking specific markers in the section underobservation can be characterized by the amount and distributionpattern of its microfilaments, an additional criterionbeing that the melanocytes carry a ciliunu
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| 4. |
- Bartosik, Jacek, et al.
(författare)
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Direct evidence for the cytomembrane derivation of Birbeck granules: the membrane-sandwich effect
- 1985
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Ingår i: Acta Dermato-Venereologica. - 1651-2057. ; 65:2, s. 157-160
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Tidskriftsartikel (refereegranskat)abstract
- Digitonin, which is known to cause extensive damage to cytomembranes in general, was found to have a most remarkable effect on epidermal Langerhans' cells. Thus, it generates a membrane-sandwiching process resulting in the formation of large discs which except for the differences in size have the same morphology as ordinary Birbeck granules. This demonstrates that the cytomembrane of the Langerhans' cell has the inherent ability to superimpose upon itself, leaving little doubt that the normal Birbeck granules derive from the cytomembrane.
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| 8. |
- Forslind, B., et al.
(författare)
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Elemental content of anagen hairs in a normal Caucasian population studies with proton induced X-ray emission (PIXE)
- 1986
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Ingår i: Scanning electron microscopy. - Chicago : IIT research institute. - 0586-5581. ; :Pt 1, s. 237-241
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Tidskriftsartikel (refereegranskat)abstract
- The elemental content of anagen hair fibers in a Caucasian population of healthy females and males in the age range 10-69 years was performed to constitute a baseline for further studies of pathological conditions. Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content. The hair fibers were all anagen hairs collected from a site little influenced by genetic and hormonal influences 1.5 cm above the right ear of the probands. An area 5-8 mm from the follicle bottom was chosen for the analysis in all cases to minimize effect of hair-do contamination. The average sulfur content was 0.049 g/g and the average zinc content 170 micrograms/g. These results were not significantly influenced by chloroform/ethanol rinsing before analysis. The calcium and chlorine contents were 330 micrograms/g and 0.0033 g/g respectively. The latter data are expected to be more seriously influenced by external factors (e.g., contamination) than sulfur and zinc. No correlation between elemental concentration and sex was found for sulfur and zinc in the present material. PIXE analysis of single hair fibers yields valuable information on the elemental composition of hair fibers and can be rapidly and efficiently performed after simple mounting procedures.
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