July - September 2011, Volume 7, Issue 3

Tehaniuc AM, Benga G

Red Blood Cell Water Permeability in Elderly People

Acta Endo (Buc) 2011, 7 (3): 299-310
doi: 10.4183/aeb.2011.299

Aim. To compare the red blood cell (RBC) diffusional water permeability (Pd) in elderly human subjects and mature\r\nsubjects.\r\nPatients and methods. 58 apparently healthy subjects, aged 65-80 years, were divided into two groups: 44 mature (35-64.9 years) and 14 elderly subjects (65-80 years). The morphological characteristics of RBCs were determined from light microscopic measurements and their Pd was measured\r\nby a NMR method. The inhibition of Pd induced by p-chloromercuribenzoate (PCMB) and the activation energy (Ea,d) of water diffusion across the RBC membrane\r\nwere also determined.\r\nResults. No significant differences between the RBCs of the two groups were found in regard with morphological parameters. Pd (10-3 cm/s) was in case of mature subjects ~ 3.1 at 15?C, 3.6 at 20?C, 4.2 at 25?C, 5.0? at 30?C, 6.1 at 37?C and 7.3 at 42?C, while for elderly subjects Pd was ~ 3.4 at 15?C, 3.9 at 20?C, 4.5 at 25?C, 5.3 at 30?C, 6.6 at 37?C and 7.9 at 42?C. Although rather small these differences were statistically significant: p<0.004 to p <0.04 at various temperatures. This means that RBCs from\r\nelderly people have a higher Pd. In agreement with this suggestion, the values of inhibition of water permeability induced by PCMB were higher for the RBCs from elderly individuals; however, the differences were not statistically significant. Ea,d was the same (~23 kJ/mol) for the RBCs from both groups. After incubation with PCMB Ea,d was ~ 37 kJ/mol for the mature individuals and ~ 31 kJ/mol for\r\nelderly individuals; however, the differences were not statistically significant.\r\nConclusion. A small, but statistically significant, increase in Pd of RBCs from elderly individuals was observed. This can be correlated with peculiarities of a less physically active organism.

Keywords: aged people, water channel proteins, red blood cell, nuclear\r\nmagnetic resonance

Correspondence: Gheorghe Benga, MD, PhD, Dhc (Mult), First Laboratory of GeneticExplorations, Cluj County Clinical Emergency Hospital, 6 Pasteur St. Cluj-Napoca 400349, ?Gheorghe Benga? Foundation, Aleea Muscel No. 19, Apt. 11, Cluj-Napoca 400076, Romania, Tel +40264594373; email: gbgbenga@gmail.com