Lena A. Lewis

Effect of Interrenalectomy on Some Blood Constituents in the Skate

special reference to mitochondria and Golgi substance). II. Origin and function based on experimental evidence; effect of centrifuging on Amoeba proteus. Ibid., pp. 278-306. MAST, S. 0., and FENNELL, R. A. 1938. The relation between temperature, salts, hydrogen-ion concentration, and frequency of ingestion of food by Amoeba. Physiol. Zo6l., ii :1-18. MAST, S. 0., and HAHNERT, W. F. 1935. Feeding, digestion, and starvation in Amoeba proteus. Physiol. Zoil., 8:252-72. MAST, S. 0., and ROOT, F. M. I916a. Observations on Amoeba feeding on Infusoria. Proc. Natl. Acad. Sci., 2:188. . i916b. Observations on Amoeba feeding on rotifers, nematodes, and ciliates, and their bearing on the surface-tension theory. Jour. Exper. Zo61., 21 :33-49. MILLER, E. D. 1937. A comparative study of the contents of the gelatinous accumulations of the culture media and the contents of the cytoplasm of Amoeba proteus and Arcella vulgaris. Jour. Morph., 6o:325-59.

Some Blood Constituents of the Normal Skate

IN PREPARATION for a study of the chemical changes produced by interrenalectomy in the skate we needed to know the values for normal animals. Smith (I929) has published normal values for electrolytes and urea in Raja laevis and R. diaphenes. At Woods Hole the most satisfactory animal for our purpose was the common skate, R. erinacea, because it was plentiful and it could be interrenalectomized without too much difficulty. Little or no data have been published on the electrolytes and urea in this species. Moreover, too little attention to the effect of inanition has been given. Kisch (1930) has shown that starvation causes a fall in blood urea, but he did not determine the electrolytes. We studied the range of variation in a large number of animals in both blood and perivisceral fluid. Then the effects of inanition and feeding were followed after it was found that plasma sodium rose with the fall in blood urea. Blood sugar and volumes per cent of erythrocytes were also determined.

Assay of Sodium-Retaining Substances.

Summary A method is described for the assay of sodium-retaining substances in which desoxycorticosterone is employed as a standard. The sodium retention produced by the unknown is compared with that of desoxycorticosterone in a normal dog on a constant diet, over a 6-hour period.

Presence of an Antagonistic Factor in Serum of Dogs Following Repeated Injections of Cortin.

It has been reported 1 that in the normal dog a marked decrease in the excretion of Na and usually an increase in the excretion of K occurs during a 6-hour period following the intravenous injection of 20-40 cat units of cortin; and that with repeated injections (at intervals of several days), the effect becomes progressively less, until there is little change in electrolyte excretion following administration of the extract. It has since been found that NH3 excretion is also increased following cortin and that with repeated injections this response is decreased. Of 9 animals injected with 20-40 cat units of cortin, all gave the characteristic electrolyte response described (Table I). Four different cortical extracts prepared in this laboratory were used. The response elicited by a given extract in different dogs was very similar (Table I). Five of these animals were injected until they became completely refractory. Failure of these animals to respond to further injections suggested the possibility that some antagonistic substance was present in the blood. Using sterile precautions, blood was taken from 2 dogs (I and 111), which had received 7 and 11 injections respectively over periods of 5 and 9 weeks. The serum was separated and stored at 4°C. Five untreated animals were given 10-25 cc. of this serum intravenously about 15 minutes previous to the injection of the usual amount of cortin. In every case in which cortin and serum were given, the Na and the NH, did not change beyond the range of the controls, whereas cortin alone always reduced the Na to a level well below that of the lowest control and increased the NH, well above the highest control value (Table 11). Decreases in Na of 86-890/, in 3 animals (I, 111, X) were shown when 0.5 cc.