ISSN:
1432-1912
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary 1. The substance P content of cow retinae has been estimated by comparing the extract from the retina with two different standard preparations (SP-S, SP-B) extracted from cow gut. The bioassay on various preparations (guinea-pig ileum, rat duodenum, hen coecum, rabbit blood pressure) gave different substance P equivalents. The standards prepared from the gut are therefore of limited sufficiency for estimating substance P in nervous tissue. The substance P content of retina was not altered by environmental light. 2. Both substance P standards (SP-S, SP-B) contained several active fractions after separation by paper- and column chromatography. The retina extract contained only one fraction corresponding to Zetler's fraction Fa. 3. The highest substance P content per mg protein has been found in the subfraction M2 which also contained the highest concentration of cholineacetylase when subcellular particles have been separated according to the method of Whittaker. 4. Separation of subcellular particles of the retina by the de Robertis method showed the highest smooth muscle stimulating activity in the “synaptic vesicle fraction” M2. The slow type of contraction produced by this fraction, however, differed from the faster type of contraction produced by the standards or the brain extracts containing substance P.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00246375
