scholarly journals HISTOCHEMICAL DIFFERENTIATION OF TWO FORMS OF GLYCOGEN SYNTHETASE

1970 ◽  
Vol 18 (10) ◽  
pp. 756-759 ◽  
Author(s):  
ALLEN A. SMITH

Glycogen synthetase exists in two forms; one form is dependent on glucose 6-phosphate while the other is not. Variations in the levels of activities of the two forms of the enzyme were observed histochemically in active and inactive eccrine sweat glands from eight rhesus monkeys. The clear cells of active sweat glands showed less glucose 6-phosphate-independent glycogen synthetase activity than the clear cells of inactive sweat glands.

Author(s):  
J. V. Briggman ◽  
J. Bigelow ◽  
H. Bank ◽  
S. S. Spicer

The prevalence of strands shown by freeze-fracture in the zonula occludens of junctional complexes is thought to correspond closely with the transepi-thelial electrical resistance and with the tightness of the junction and its obstruction to paracellular flow.1 The complexity of the network of junc¬tional complex strands does not appear invariably related to the degree of tightness of the junction, however, as rabbit ileal junctions have a complex network of strands and are permeable to lanthanum. In human eccrine sweat glands the extent of paracellular relative to transcellular flow remains unknown, both for secretion of the isotonic precursor fluid by the coil and for resorption of a hypertonic solution by the duct. The studies reported here undertook, therefore, to determine with the freeze-fracture technique the complexity of the network of ridges in the junctional complexes between cells in the secretory coil and the sweat ducts. Glands from a patient with cystic fibrosis were also examined because an alteration in junctional strands could underlie the decreased Na+ resorption by sweat ducts in this disease. Freeze-fracture replicas were prepared by standard procedures on isolated coil and duct segments of human sweat glands. Junctional complexes between clear cells, between dark cells and between clear and dark cells on the main lumen, and between clear cells on intercellular canaliculi of the coil con¬tained abundant anastomosing closely spaced strands averaging 6.4 + 0.7 (mean + SE) and 9.0 +0.5 (Fig. 1) per complex, respectively. Thus, the junctions in the intercellular canaliculi of the coil appeared comparable in complexity to those of tight epithlia. Occasional junctions exhibited, in addition, 2 to 5 widely spaced anastomosing strands in a very close network basal to the compact network. The fewer junctional complexes observed thus far between the superficial duct cells consisted on the average of 6 strands arranged in a close network and 1 to 4 underlying strands that lay widely separated from one another (Fig. 2). The duct epitelium would, thus, be judged slightly more "leaky" than the coil. Infrequent junctional complexes observed to date in the secretory coil segment of a cystic fibrosis specimen disclosed rela¬tively few closely crowded strands.


1961 ◽  
Vol 11 (2) ◽  
pp. 385-402 ◽  
Author(s):  
Bryce L. Munger

The electron microscopy of human eccrine sweat glands has been studied before and after stimulation by pilocarpine iontophoresis. The identity of the dark and clear cells in the secretory segment as defined by Montagna et al. (23) was determined by studying serial sections, thin for electron microscopy and thick for light microscopy. Cells with numerous apical secretory vacuoles are termed mucoid (dark) cells, since these vacuoles stain positively for acid mucopolysaccharide. Clear cells are intimately associated with intercellular canaliculi. The "cuticular border" of surface cells of the duct is a condensation of tonofilaments and granules. Numerous mitochondria are concentrated in basal cells of the duct. The presence of mucoid cells in the secretory segment may bear on the interpretation of the pathologic findings in the disease cystic fibrosis of the pancreas, and suggests that this disease may be due to a basic disorder of mucopolysaccharide production. The possible roles of the various cellular components in the elaboration of sweat are discussed.


1970 ◽  
Vol 54 (3) ◽  
pp. 229-232 ◽  
Author(s):  
Becky B. Johnson ◽  
Robert E. Johnson

2017 ◽  
Vol 42 (5) ◽  
pp. 548-550
Author(s):  
Y. Saito ◽  
Y. Shimomura ◽  
R. Abe

1981 ◽  
Vol 240 (1) ◽  
pp. R44-R51 ◽  
Author(s):  
K. Sato ◽  
F. Sato

Pharmacologic responsiveness of the eccrine sweat gland has never been studied under well-defined in vitro experimental conditions. Using isolated cannulated single monkey palm eccrine sweat glands, the dose response to both cholinergic and alpha- and beta-adrenergic agents and the effects of various antagonists on agonists were studied. The maximal sweat rate was highest after stimulation with cholinergic agonists, was lower with the beta-adrenergic agonist, and was least with the alpha-adrenergic agonist. Each secretory response was inhibited by its specific antagonist. Attempts to demonstrate the spare receptor, if any, by means of preincubation of the glands with N-(2-chlorethyl)dibenzylamine (Dibenamine) were unsuccessful. From the hyperbolic dose-response curves the values for KA and KB, dissociation constants for agonists and antagonists, respectively, were thus tentatively estimated according to Clark's classical receptor theory. Schild plots for each agonist-antagonist interaction produced straight lines with slopes of near unity, indicating the adequacy of the methodology. It was concluded that the isolated eccrine sweat glands retain their pharmacologic viability in vitro and show responsiveness to cholinergic as well as both alpha- and beta-adrenergic stimulations.


2016 ◽  
Vol 48 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Haihong Li ◽  
Liyun Chen ◽  
Mingjun Zhang ◽  
Bingna Zhang

2006 ◽  
Vol 126 (6) ◽  
pp. 1220-1225 ◽  
Author(s):  
Caroline J. Morgan ◽  
Peter S. Friedmann ◽  
Martin K. Church ◽  
Geraldine F. Clough

1998 ◽  
Vol 18 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Li-Min Lao ◽  
Masanobu Kumakiri ◽  
Hiroshi Mima ◽  
Hiroaki Kuwahara ◽  
Hisaya Ishida ◽  
...  

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