Biochemical Studies of Isolated 

 Golgi Membranes 



EDWARD L. KUFF and ALBERT J. DALTON 



National Cancer Institute 

 Bethesda, Maryland 



UNLIKE THE OTHER SUBCELLULAR COMPONENTS discussed in this symposium, 

 structures encompassed by the terms 'Golgi system' or 'Golgi complex' 

 must still be described essentially in morphological terms (21). At the level of 

 light microscopy, Golgi structures have been defined primarily by their capacity 

 to react with osmium tetroxide or silver salts under controlled conditions of post- 

 fixation impregnation (10). The greater resolving power of the electron micro- 

 scope has revealed that a complex and rather characteristic ultrastructure under- 

 lies the visual images thus produced (4, 5, 25, 11, 24). For exainple, in the case 

 of the epithelial cells of the epididymis, we know that the Golgi image observed 

 with the light microscope after application of the classical osmium impregnation 

 techniques results from the deposition of metal upon the complex system of 

 membranes and vacuoles shown in figure i (4). In a number of other instances, 

 similar correlations between light and electron microscopy have been made 

 (6, 14); and we are now accustomed to speak of such ordered arrays of smooth- 

 surfaced membranes, presumably consisting of flattened sacs and appearing gen- 

 erally in association with small vesicles and vacuoles of varying size, as systems 

 of Golgi membranes. It is not known whether these morphologically similar 

 systems have identical biochemical composition or function wherever they are 

 found or even whether they constitute entities entirely separate from the other 

 cytoplasmic membranes. Indeed, these are the major problems with which we 

 are concerned. 



The results to be presented deal only with rat epididymis. The virtue of this 

 tissue for purposes of the present study rests in the very extensive development 

 of the Golgi system in the cells that line the highly convoluted epididymal duct 

 (figs. I and 2). It has the disadvantage that we know very little about the 

 specific cellular functions of the epididymis (16). As will be shown, it has been 

 possible to isolate Golgi membranes that retain many of the structural details 

 that are seen in the intact cells. Furthermore, there appear to be certain bio- 

 chemical respects in which the isolated Golgi material differs from the other 

 particulate structures of intracellular origin. 



Several years ago, it was reported that a characteristic positive image could 

 be observed with the phase contrast microscope in the supranuclear or Golgi 



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