Allan D. Bass

Effect of cortisone on liver nucleoproteins.

Abstract Administration of cortisone 100 μg/g of mouse/day to male Swiss Albino mice produces only temporary modifications of the cellular components of the liver which indicate rapid adaptation of this tissue to cortisone. There is an increased deposition of glycogen during the first 24 hours of cortisone administration followed by a rapid return to normal values. Fat concentration in the liver cell reaches a peak at 5 days. Concentrations of RNA and nitrogen are lowered temporarily with this large dose of cortisone and return to control levels within 7 days. It seems reasonable to conclude that modifications in ploidy distribution of hepatic parenchymal nuclei induced by cortisone can explain the alterations in average DNA content per nucleus.

Ploidy Distribution of Nuclei in Rat Liver Following Hypophysectomy.

Summary1. Percentage of diploid nuclei observed in livers of young adult hypophysectomized rats is greater than that seen in control animals of comparable age and weight. 2. In the hypophysectomized rat there is a small but significant increase in percentage of binucleate liver cells. 3. Total reduction in mitotic index in 125–135 g rats is no greater in 21 days hypophysectomized rats than in the unoperated animals; however, rate of change may be more rapid in operated animals.Summary 1. Percentage of diploid nuclei observed in livers of young adult hypophysectomized rats is greater than that seen in control animals of comparable age and weight. 2. In the hypophysectomized rat there is a small but significant increase in percentage of binucleate liver cells. 3. Total reduction in mitotic index in 125–135 g rats is no greater in 21 days hypophysectomized rats than in the unoperated animals; however, rate of change may be more rapid in operated animals.

Effect of epinephrine-liberated pancreatic substance on uptake of alpha amino-isobutyric acid by isolated perfused rat liver

Abstract The effluent from an isolated perfused pancreas infused with epinephrine (75 mg/min) contains some substance, not insulin, which, when infused into isolated rat liver caused increased uptake of alpha aminoisobutyric acid and increased release of glucose by the liver. The action of this substance on the liver closely resembles that of glucagon and it is proposed that the substance released from the pancreas is indeed glucagon.

Effect of Hypophysectomy on Liver Nucleoproteins.

SummaryEarlier investigations on liver nucleoprotein changes following hypophysectomy have been extended showing that the DNA per average nucleus is increased. This is not restored to normal values rapidly, since treatment for one week with growth hormone effects no appreciable reduction. These data obtained by chemical analyses strongly indicated that following hypophysectomy there was an increase in the frequency of nuclei of higher ploidy. This was found to be the case when the nuclei were examined by microspectropho tome trie technics. The results suggest that growth hormone may be important in effecting the conversion of diploid to the tetraploid nuclei. However, tetraploid nuclei may be converted to octaploid nuclei in the absence of growth hormone.Summary Earlier investigations on liver nucleoprotein changes following hypophysectomy have been extended showing that the DNA per average nucleus is increased. This is not restored to normal values rapidly, since treatment for one week with growth hormone effects no appreciable reduction. These data obtained by chemical analyses strongly indicated that following hypophysectomy there was an increase in the frequency of nuclei of higher ploidy. This was found to be the case when the nuclei were examined by microspectropho tome trie technics. The results suggest that growth hormone may be important in effecting the conversion of diploid to the tetraploid nuclei. However, tetraploid nuclei may be converted to octaploid nuclei in the absence of growth hormone.