COMPARATIVE NUCLEAR-MAGNETIC-RESONANCE STUDIES OF DIFFUSIONAL WATER PERMEABILITY OF RED-BLOOD-CELLS FROM DIFFERENT SPECIES .5. RABBIT (ORYCTOLAGUS-CUNICULUS)
G. Benga et al., COMPARATIVE NUCLEAR-MAGNETIC-RESONANCE STUDIES OF DIFFUSIONAL WATER PERMEABILITY OF RED-BLOOD-CELLS FROM DIFFERENT SPECIES .5. RABBIT (ORYCTOLAGUS-CUNICULUS), Comparative biochemistry and physiology. B. Comparative biochemistry, 106(2), 1993, pp. 281-285
1. The diffusional water permeability (P(d)) of rabbit red blood cell
(RBC) membrane has been monitored by a doping nuclear magnetic resonan
ce (NMR) technique on control cells and following inhibition with p-ch
loromercuribenzene sulfonate (PCMBS). 2. The values of P(d) were aroun
d 6.3 x 10(-3) cm/sec at 15-degrees-C, 7.0 x 10(-3) cm/sec at 20-degre
es-C, 8.0 x 10(-3) cm/sec at 25-degrees-C, 9.1 x 10(-3) cm/sec at 30-d
egrees-C and 10.7 x 10(-3) cm/sec at 37-degrees-C. 3. Systematic studi
es on the effects of PCMBS on water diffusion indicated that the maxim
al inhibition was reached in 15 min at 37-degrees-C with 0.5 mM PCM BS
. 4. The values of maximal inhibition were around 71-74% at all temper
atures. 5. The basal permeability to water was estimated as 1.6 x 10(-
3) cm/sec at 15-degrees-C, 2.0 x 10(-3) cm/sec at 20-degrees-C, 2.4 x
10(-3) cm/sec at 25-degrees-C, 2.6 x 10(-3) cm/sec at 30-degrees-C, an
d 3.1 x 10(-3) cm/sec at 37-degrees-C. 6. The activation energy of wat
er diffusion was around 18 kJ/mol and increased to 27 kcal/mol after i
ncubation with PCMBS in conditions of maximal inhibition of water diff
usion. 7. The membrane polypeptide electrophoretic pattern of rabbit R
BCs has been compared with its human counterpart. 8. The rabbit membra
ne contained a higher amount of spectrin (bands 1 and 2), while the ba
nd 6 (glyceraldehyde-3-phosphate dehydrogenase) was markedly less inte
nse. 9. Considerable differences in the electrophoretic patterns of th
e two sources of RBC membranes appeared in the bands migrating in the
band 4.5 region and in front of band 7, where some polypeptides were a
pparent in higher amounts in the rabbit RBC membrane.