摘要:

AbstractThe histochemical method of Häusler was employed to demonstrate carbonic anhydrase (CA, carbonate hydrolase, 4.2.1.1.) in tissue sections. The CA reaction was inhibited in the presence of 5 mM acetazolamide. In the frog and fish retinas the CA activity was positive in the Müller fiber, the laminated segment of the cones and the myelin of the axons, and was negative in the laminated segment of the rods, the photoreceptor ellipsoid and myoid, the horizontal, bipolar, amacrine and ganglion cells, and the pigment epithelium. In the spinal cord of cat and fish the CA activity was positive in the myelin of the axons, the perineuronal oligodendroglia and the protoplasmic astrocytes, and was negative in the cell body, dendrite, and axon of the neurons and in the fibrous astrocytes. In the dorsal root ganglion of the cat CA reaction was positive in the satellite cells and the myelin, and was negative in the neuronal cell body and its processes. The capillaries in central nervous tissue show no CA reaction. The erythrocyte is CA positive while the mitochondria are CA negativ

ISSN:0360-4012    

DOI:10.1002/jnr.490060112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractRecently we have shown that nerve growth factor (NGF) influences the coupled movements of Na+and K+across the membrane of chick embryo dorsal root ganglion (DRG) and other target cells. These ionic effects of NGF are consistent with a model in which NGF acts through the classical Na+,K+‐ATPase pump. Direct evidence for NGF‐induced alteration of this pump has been sought in the present study through two approaches. In one approach, DRG cell dissociates were incubated for 6 hours without NGF (to allow development of the ionic defect), and [3H]ouabain binding to the cells was measured before and during a delayed administration of NGF. No differences were detected in either total binding or binding time. In the second approach, intact DRG or DRG dissociates were incubated for 6 hours with or without NGF, or received NGF after 6 hours of deprivation, and Na+,K+‐ATPase (ouabain‐sensitive) activity was measured in the corresponding microsomal preparations. Activity levels were found to be the same in all cases, and were unchanged by addition of NGF directly to the enzyme preparations. Different concentrations of Na+, K+, or ATP affected in identical manners the enzyme preparations from NGF‐treated and NGF‐deprived ganglia, speaking against NGF‐imposed changes in the affinities of the corresponding enzyme sites. Also unsuccessful were attempts to reveal NGF‐related differences by testing ouabain‐sensitive ATPase activity (1) in the presence of varying concentrations of cyclic AMP or of Ca2+, (2) after treatment with Triton X‐‐100 or in the presence of vanadate, or (3) on addition of a 100,000g DRG extract. These negative findings are discussed in terms of the Na+,K+‐ATPase hy

ISSN:0360-4012    

DOI:10.1002/jnr.490060113

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

ISSN:0360-4012    

DOI:10.1002/jnr.490060114

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

ISSN:0360-4012    

DOI:10.1002/jnr.490060115

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

ISSN:0360-4012    

DOI:10.1002/jnr.490060101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY