H. Teir

Effect of necrotic liver tissue on regeneration in hepatectomized rats

Abstract Necrotic liver tissue stimulated rat liver regeneration in hepatectomized rats both after application of liver samples in the abdominal cavity and after ligation of the median or left lobes. Intraperitoneally injected homogenates of liver tissue incubated at 37 °C for 24 hr caused a reproducible increase in mitotic frequency and in the weight index in hepatectomized rats.

Influence of intraperitoneally injected homogenates of the outer orbital gland and the liver on RNA and DNA in these organs in rats

Abstract 1. 1. The influence of intraperitoneally injected homogenates of the outer orbital gland and liver from young rats and of regenerating liver on the nucleic acid concentration of these organs has been studied. 2. 2. The influence of the orbital homogenate was specific, causing a significant increase in RNA and DNA of the orbital gland. It showed no influence on RNA and DNA of the liver. The influence of the homogenate prepared from the liver of new-born rats was not specific: it caused an increase in the DNA concentration of the outer orbital gland, and its influence on the liver was questionable; an increase in RNA was noted in one case only. The homogenate from the liver of 6-week-old rats had no influence on the liver; its influence on the orbital gland was not studied. The homogenate from the regenerating liver had no influence on the outer orbital gland, while RNA of the liver showed a significant increase in all experiments. The DNA had increased in one experiment only.

SPECIFIC INCREASE IN THE UTILISATION OF 3H-THYMIDINE BY LIVER CELLS IN HEPATECTOMISED MICE FOLLOWING INJECTION OF AUTOLYTIC LIVER TISSUE.

Abstract Autolytic, liver tissue injected into the peritoneal cavity of the mouse after 70 percent hepatectomy stimulated specifically the DNA synthesis of the hepatic parenchymal cells, No stimulation was demonstrated in the mesenchymal cells of the liver and in the cells of the renal tubules, gastric mucosa or epidermis.

The hexosamine level in liver and serum in rat after partial hepatectomy.

Abstract The concentration of hexosamine in liver and serum in rat was determined before and after 70 per cent hepatectomy. On the first day after partial hepatectomy the hexosamine concentration was significantly decreased in both the liver and the serum, on the second day still more in the liver but no longer significantly in the serum. The hexosamine levels were simultaneously increased in both the liver and the serum of the laparatomized controls. Seven days after the operations, the hexosamine concentrations were at the normal level. The results support the assumption that the liver has a prominent role in the production of serum hexosamine.

POLYPLOIDY ALTERATIONS IN THE OUTER ORBITAL GLAND OF THE RAT AFTER REPEATED INJECTIONS OF HOMOLOGOUS HOMOGENATES

Publisher Summary This chapter discusses polyploidy alterations in the outer orbital gland of the rat after repeated injections of homologous homogenates. A remarkable variation in the nuclear size occurs in the outer orbital gland or exorbital lacrimal, extraorbital, or Loewenthals gland of the rat. In a study described in the chapter, neither the development nor the size and weight of the outer orbital gland were affected by repeated intraperitoneal injections of orbital gland tissue homogenate of two-week-old rats whether the injections were started in rats aged 2 weeks, 2 months, or 1 year. The size and weight of the organs were normal also in cases with higher polyploidy stages. This is in accordance with the polyploidy findings for amphibians. Comparison of individuals from haploid to pentaploid reveals that ploidy has little effect on body size. It seems that polyploidy stages do not produce any effect on the size of organs. No tumors were found in the gland. A malignant thyroid tumor and a benign breast tumor could be a result of mere coincidence and not of the homogenate injections. A common feature of the histological and cytological changes observed was that they caused loss of parenchyma. It is possible that the occurrence of higher polyploidy stages is a mere compensatory step, as has been observed in the liver after partial hepatectomy and in the kidney after nephrectomy.