Lactate dehydrogenase activation volumes

Fig. 9. Simultaneous plots of reaction rate (relative Vmax) and activation volume (AV() for the lactate dehydrogenase system as functions of salt (KSCN) concentration. This mirror image may be explained by the similarity between Eq. (134) and Eq. (136). (By courtesy of Prof. G. N. Somero, unpublished.)...

The breakdown of fat leads to a transient increase in body water. Normally, however, an osmotic diuresis soon reduces the blood volume even though glomerular filtration may be impaired, as demonstrated by increased serum creatinine concentration and reduced creatinine clearance. Hepatic blood supply may also be reduced. BSP retention is increased, and the serum bilirubin rises the unconjugated bilirubin more than doubles within 48 hours. Increased serum activities of aspartate and alanine aminotransferase and of lactate dehydrogenase are observed. The enzyme changes may be linked more to focal necrosis of the liver than to general circulatory impairment. 

The cytotoxicity tests were performed with the use of the direct contact method on the extracts obtained by an 8-d incubation of the polymer PSU and PSU/Ag composite samples, placed at the bottom of the well of a 24-well culture plate, in 2 ml of culture mediiun. The incubation was conducted at 37°C in air atmosphere with a 5% content of C02and 100% of relative air humidity. Next, 0.2 ml of ihe obtained extract and its fourfold dilution in a proper culture medium was dosed for the cultures of human osteoblasts (HTB-85 cell line, ATCC, USA) and human fibroblasts (CRL-7422 cell line, ATCC, USA) adhered to the bottom of the well of a 96-well culture plate. In the case of the control test, the extract of the examined samples was replaced by the proper volume of culture medium. The plates were incubated at 37°C in air atmosphere with a 5% content of CO and 100% of relative air humidity. The incubation time for two parallelly conducted experiments was 24 h and 48 h. The cytotoxicity of PSU and the PSU/Ag composites was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium (MTT) assay [9, 10] and by lactate dehydrogenase (LDH) activity measured with the use of a commercial cytotoxicity assay kit (Roche Diagnostics GmbH, Mannheim, Germany), [11]. Each of the indications was repeated three times. 

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