Microcalorimetric Techniques for Metabolic Studies of Two cell Systems
Andre Belico de Vasconcelos 1; Alexandre Martins Costa Santos 2; Marcos Aurelio de santana 2; Fabiana Cristina Varago 1; Monique de Albuquerque Lagares 1; Marcelo Matos Santoro 2.
Department of Veterinarian Clinic and Surgey, Veterinarian School, UFMG, Belo Horizonte, MG, Brazil 1; Laboratory of Enzimology and Physical-Chemistry of Proteins, Department of Biochemistry and immunology, ICB, UFMG, Belo Horizonte, MG, Brazil 2.
When cells are submitted to different experimental conditions, an early results is a shift in type and rate of metabolism to reflect their new conditions. The aim of the work was evaluate for conduction microcalorimeter the metabolic rates of living cell systems, like yeast and spermatic cells.
The concentration spermatic cells and yeast were of 100 x 106 cells/ml in medium supplemented 0.05g/l gentamicin to prevent contamination. All experiments were made at (300C + 10C).
In this work were evaluated: Firstly, the effect of different concentrations of glucose (range 0 to 12) in the medium preservation upon the metabolic rates of yeast and spermatozoon samples.Secondly, the effect of metabolic inhibitors in order to distinguish respiratory and fermentative processes occurring in yeast living cells and finally, the effect of the damage of spermatozoa plasmatic membrane after centrifugation.
The results in both systems cells high glucose concentrations cause a "glucose effect". This effect induces the cells to change to anaerobic metabolism because, in a closed calorimetric cell, the concentration of O2 lowers when glucose concentration is large. The yeast results metabolic rates showed a strong inhibitory effect on yeast metabolism of glucose in the presence of iodoacetate (80%), but a small effect when using succinate as energetic source in the presence of malonate (5%). This would be due to a switch modulation in the fermentative / respiratory machinery of the yeast cells. The spermatic cells, the centrifugation procedure was harmful to the percentage of viable cells and to their plasma membrane integrity.
Microcalorimetry is a unique technique able to give direct thermodynamic information about the whole vectorized metabolic process in living organisms like yeast. Beyond, the information obtained with microcalorimetry may add to other parameters of routine evaluation of equine semen. This is a good example of adaptation of a new analytical technique of high sensitivity to studies of practical interest in the area of biological cells.
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