G. Benga et al., NMR-STUDIES OF DIFFUSIONAL WATER PERMEABILITY OF ERYTHROCYTES FROM 8 SPECIES OF MARSUPIAL, Comparative biochemistry and physiology. Part A, Physiology, 106(3), 1993, pp. 515-518
1. The diffusional water permeability (P(d)) of the red blood cell (RB
C) membranes of eight species of marsupial were monitored by using a M
n2+-doping H-1 nuclear magnetic resonance (NMR) technique at 400 MHz (
9.4T). 2. There were differences in the water permeability of the RBC
membranes among the species investigated. 3. On the basis of parameter
s characterizing the RBC water permeability the animals could be divid
ed in two groups. 4. For the first group, including the large macropod
id marsupials, eastern grey kangaroo (Macropus giganteus) and red kang
aroo (M. rufus), the values of P(d) were 5.4-6.1 x 10(-3) cm/sec at 24
.6-degrees-C; 6.6-7.2 x 10(-3) cm/sec at 30-degrees-C; 7.8-9.1 x 10(-3
) cm/sec at 37-degrees-C and 9.3-11.1 x 10(-3) cm/sec at 42.1-degrees-
C. 5. The values of the activation energy for the diffusion process (E
(a,d)) ranged from 24 27 kJ/mol. 6. For the second group, including ba
ndicoot (Isoodon macrourus), bilby (Macrotis lagotis sagitta), Tasmani
an devil (Sarcophilus harrisii), koala (Phascolarctis cinereus), brush
tailed possum (Trichosurus vulpecula), and Goodfellow's tree kangaroo
(Dendrolagus goodfellowi), the values of P(d) were higher, ranging fr
om 8.1-10.4 x 10(-3) cm/sec at 24.6-degrees-C; 8.9-11.8 x 10(-3) cm/se
c at 30-degrees-C; 10.3-13.7 x 10(-3) cm/sec at 37-degrees-C and 11.9-
15.3 x 10(-3) cm/sec at 42.1-degrees-C. 7. In parallel with the high w
ater permeability the RBC of the marsupials in the second group exhibi
ted lower values of E(a,d) ranging from 15 21 kJ/mol, except for Goodf
ellow's tree kangaroo, for which the E(a,d) was approximately 25 kJ/mo
l.