Measurements of macromolecule-bound and ultra-filtrable polyamines in rat liver homogenized without buffer.
Ultra-filtrable and macromolecule-bound polyamines in rat liver homogenates, made without buffer, were determined, using Potter-Elvehjem homogenizer and commercially available, pressure-aided ultrafiltration device with a membrane pore size that allows passage of particles of molecular weight no larger than 5000. About 90% of polyamines in the liver were shown to be equilibrated with externally added 15N-labeled polyamines, based on the difference in the ratio of the natural to 15N-labeled polyamine in the liver homogenate and the ultrafiltrate. The entire amount of ultrafiltrate in the homogenized liver, required for calculation of the amounts of ultra-filtrable and macromolecule-bound polyamines, was estimated to be about 0.25 g in one gram of the homogenate, using a limited dilution curve of spermine in the ultrafiltrate with phosphate buffered saline and distilled water. With this value, ultra-filtrable polyamines in normal rat liver homogenate were calculated as about 25%, 8%, and 2% of the total amount of putrescine, spermidine, and spermine, respectively. The method was then used to measure ultra-filtrable and macromolecule-bound polyamines in regenerating rat liver homogenates, to examine possible changes of polyamines during cell growth. The method was also applied to measure other ultra-filtrable compounds such as amino acids and inorganic ions in rat liver homogenate.
Xu
Y J
YJ
Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama, Japan.
Furuumi
N
N
Samejima
K
K
Niitsu
M
M
Shirahata
A
A
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D015317:Biogenic Polyamines / Q000032:analysis*; D008099:Liver / Q000737:chemistry*; D008115:Liver Regeneration; D046911:Macromolecular Substances; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014462:Ultrafiltration
D000596:Amino Acids; D015317:Biogenic Polyamines; D046911:Macromolecular Substances