Comparative NMR studies of diffusional water permeability of red blood cells from different species: XVI Dingo (Canis familiaris dingo) and dog (Canis familiaris)

2010 
As part of a programme of comparative measurements of Pd (diffusional water permeability) the RBCs (red blood cells) from dingo (Canis familiaris dingo) and greyhound dog (Canis familiaris) were studied. The morphologies of the dingo and greyhound RBCs [examined by light and SEM (scanning electron microscopy)] were found to be very similar, with regard to aspect ratio and size; the mean diameters were estimated to be the same (,7.2 mm) for both dingo and greyhound RBCs. The water diffusional permeability was monitored by using an Mn 2+ -doping 1 H NMR technique at 400 MHz. The Pd (cm/s) values of dingo and greyhound RBCs were similar: 6.5610 23 at 25˚C, 7.5610 23 at 30˚C, 10610 23 at 37˚C and 11.5610 23 at 42˚C. The inhibitory effect of a mercury-containing SH (sulfhydryl)-modifying reagent PCMBS (pchloromercuribenzene sulfonate) was investigated. The maximal inhibition of dingo and greyhound RBCs was reached in 15‐30 min at 37˚C with 2 mmol/l PCMBS. The values of maximal inhibition were in the range 72‐74% when measured at 25˚C and 30˚C, and ,66% at 37˚C. The lowest value of Pd (corresponding to the basal permeability to water) was ,2‐ 3610 23 cm/s in the temperature range 25‐37˚C. The Ea,d (activation energy of water diffusion) was 25 kJ/mol for dingo RBC and 23 kJ/mol for greyhound RBCs. After incubation with PCMBS, the values of Ea,d increased, reaching 46‐48 kJ/mol in the condition of maximal inhibition of water exchange. The electrophoretograms of membrane polypeptides of the dingo and greyhound RBCs were compared and seen to be very similar. We postulate that the RBC parameters reported in the present study are characteristic of all canine species and, in particular in the two cases presented here, these parameters have not been changed by the peculiar Australian habitat over the millennia (as in the case of the dingo) or over shorter time periods, decades or centuries (as in the case of the domestic greyhound).
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    51
    References
    7
    Citations
    NaN
    KQI
    []