PHYSICAL CHEMISTRY OF MUSCLE PLASMA^ 



FILIPPO BOTTAZZI 



(Physiological Institute, University of Naples, Italy) 



My experiments have been made on striated muscles of oxen, 

 dogs, Scyüium stellare and Dentex vulgaris, and on piain muscles 

 {M. retractor penis) of oxen. In the case of the dogs, the muscles 

 were removed after flushing the blood vessels with 0.9 per cent. 

 Solution of sodium chlorid (sometimes cooled to 4-5° C). In 

 nearly all cases the muscles were preserved in dry vessels at low 

 temperatures. They were freed from fatty and connective tissues, 

 then minced, thoroughly pounded with quartz sand and infusorial 

 earth, and plasma obtained in a Buchner press, generally at a 

 maximum pressure of about 350 atmospheres. In some experi- 

 ments the irritability of the animal (Scyllium) was abolished by 

 gradually cooling it to about — 2° C, so that on cutting off the 

 body musculature no contraction ensued. The muscle plasma 

 (about 600-800 c.c.) was collected in dry vessels, centrifuged for 

 an hour and preserved in a refrigerator. 



The plasma of striated mammalian muscle was always deep red 

 in color and rather turbid; that of fish muscle was less colored. 

 The plasma of piain muscle was always opalescent and almost color- 

 less. The microscopic examination, made with powerful apochro- 

 matic objectives, revealed no trace of morphologic Clements or 

 granules in the centrifuged plasma, which always appeared to be 

 perfectly homogeneous. But ultramicroscopic examination revealed 

 the presence of innumerable very small and highly brilliant granules, 

 mixed with a relatively small number of coarse particles, which have 

 nothing to do with the granules, being composed of fat, glycogen 

 and nuclear or sarcoplasmic f ragments. The existence of the ultra- 



^ Presented at the eighty-first meeting of the British Association for the 

 Advancement of Science, in Dundee, September, 1912. In these researches I 

 was aided by my assistant Dr. G. Quagliariello. 



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