Hormonal Effects on Liver and Kidney Cytoplasm

Abstract

1. Differential centrifugation, in 0\m=.\25m sucrose solution, has been performed with rat liver and kidney tissue to ascertain whether the yield and composition of the cytoplasmic fractions (mitochondrial, microsome and supernatant fractions) depend on the hormonal status of the animal.2. After hypophysectomy the ribonucleic acid (RNA) of the mitochondrial fraction from liver underwent a decrease (in terms of body weight) which was sufficient to account for the fall in the RNA of the liver as a whole. There was also a decrease in the yield of the mitochondrial fraction. Administration of pituitary growth hormone (GH) to hypophysectomized rats not only restored to normal the amount of RNA in the mitochondrial fraction and the yield of that fraction, but also led to an apparent shift of RNA from the microsome fraction to the supernatant fraction. A further change observed after hypophysectomy, whether or not GH had been given, was a rise in the yield of the microsome fraction. Hypophysectomized rats given thyrotrophin (TSH) did not show significant cytoplasmic changes as found with untreated hypophysectomized rats, but it was not possible to conclude that TSH had actually reversed the effects of hypophysectomy.3. Castrated rats showed no abnormalities in the yields of the liver cytoplasmic fractions or in the concentration of RNA in the fractions. Alloxan-diabetic rats showed a rise in the yield of the supernatant fraction from liver. 4. Untreated adrenalectomized rats showed a rise in liver deoxyribonucleic acid, a fall in the yield of the liver mitochondrial fraction, but not in the amount of RNA in that fraction, and a rise in the amount of RNA in the supernatant fraction. Replacement therapy with various adrenocorticoids was attempted, with only partial success. 5. In contrast with the RNA content, the phospholipid content of the liver cytoplasmic fractions was not, in general, dependent on hormonal status.6. Determinations of the yield and composition (RNA and phospholipid) of the cytoplasmic fractions from kidney disclosed certain hormonal effects, differing from those observed with liver; for example, the kidneys from hypophysectomized rats furnished microsome fractions in lowered yield but with an increased concentration of RNA.The technique of differential centrifugation, whereby mitochondria and other particulate constituents can be isolated from disrupted cells, has been widely used in bio¬ chemical studies on normal and cancerous liver. Hitherto the technique has been little applied in the study of hormonal influences on liver.At the outset ofthe present study, adult female rats were subjected to adrenalectomy or to treatment with pituitary growth hormone (GH). As reported elsewhere [Reid, 1954[Reid, , 1955 a], neither liver nor kidney from the rats given GH showed significant changes in cytoplasmic composition as studied by differential centrifugation. With adrenalectomy the composition of liver cytoplasm did show certain changes (as described below), the reversal of which was attempted with appropria...

The chemistry of the injured cell, by Roy Cameron and W.G. Spector.

“…Alloxan diabetes in the rat increases the yield of supernatant liver fraction at the cost of other components. Castration produces no change in the liver fractions (Reid, 1956) .…”

Phosphomonoesterase hydrolysis of polyphosphoinositides in rat kidney: Properties and subcellular localization of the enzyme system

“…Lactate dehydrogenase and I-galactosidase followed the pattern expected for a soluble enzyme adsorbed to a new surface produced at homogenization. RNA in the kidney is present in the soluble phase in appreciable amounts but is also attached to the endoplasmic reticulum in the form of ribosomes (Reid, 1956 cell and is released into the supernatant mechanically on homogenization. This seems unlikely since use of the more gentle Dounce homogenizer minimized lysosomal acid phosphatase release into the supernatant, but the percentage of triphosphoinositide and diphosphoinositide phosphatases present in this fraction remained unchanged (Table 4 and Fig.…”