(;()L(;I MhMBRANES 



125 



Fk;. 111. C^Diiip.irison of cytoplas- 

 mic fractions of rat epididymis. 

 The fractions are indicated on tlie 

 left: Golgi and Under-Golgi were 

 obtained by centrifugation for 30 

 minutes at 35,600 rpm of a gra- 

 dient tube prepared as shown in 

 figure 5: mitochondrial (Mito.), 

 microsomal (Micro.), and post- 

 microsomal (Post-micro.) fractions 

 by differential centrifugation of an 

 cpididymal homogcnate jirepared 

 in 0.88 M sucrose. The width of 

 the bars is without significance. 

 For further details, see text. 



GOLGI 



UNDER 

 GOLGI 



MITO. 

 MICRO 



POST- 

 MICRO. 



DPNH- 

 LIPID RNA ALK. ACID CYTOC 

 P P'ASE P'ASE RED. 



^a 



i 



E^ 



I 



10 



- 8 



- 6 



- 4 



- 2 



< 



tr 



LlJ 



o 



z 

 o 

 o 



> 



< 



_l 



LU 



Only lipid phosphorus and acid phosphatase activity were concentrated in the 

 Golgi fraction. The results are in agreement with recent histochemical studies that 

 have demonstrated a high concentration of acid phosphatase activity (17, 3) but 

 no alkaline phosphatase activity (17, 3, 15) in the Cxolgi region of epididymal 

 cells. Assuming that no other nitrogen-containing compounds were present, it 

 may be calculated that the Golgi material contained approximately equal amounts 

 of phospholipid and protein. The relative proportions of lipid phosphorus, alka- 

 line phosphatase and DPNH-cyto.r reductase would appear to differentiate the 

 Golgi material from the other subcellular fractions. RNA was not concentrated 

 in the (iolgi fraction, nor were a number of enzymatic activities that might be 

 briefly listed: cytochrome oxidase (23), deoxyribonuclease (23), /:?-glucuronidase, 

 esterase, and ATPase (release of inorganic phosphorus from ATP in the pres- 

 ence of magnesium ion). 



It is evident, therefore, that we have not as yet uncovered any distinctive bio- 

 chemical property of the isolated Golgi structures. Actually, the rather negative 

 picture that has emerged with regard to enzymatic activity might be significant 

 in itself, since the possibility must be kept in mind that the Golgi membranes 

 may carry out their roles in secretion and absorption in some chiefly non-en- 

 zymatic fashion. Of course, it would be highly desirable to study material iso- 

 lated from other sources where we have a better conception ot cellular function. 

 This is being attempted at the present time. Meanwhile, we have, in this instance 

 at least, a preparation that appears to consist mainly ot morphologically identifi- 

 able Golgi material. It is hopeti that an analytic and dynamic study of the lipid 



