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Generation of light sickle erythrocytes from dense sickle erythrocytes during fast oxy/deoxy cycling


, : Generation of light sickle erythrocytes from dense sickle erythrocytes during fast oxy/deoxy cycling. Blood 96(11 Part 1): 601a, November 16

Recent studies have identified older, low-density sickle red blood cells (SS RBC) that are resistant to dehydration mediated by valinomycin or the Ca-activated K channel (K(Ca)). We hypothesize that these cells derive from dense SS RBC that become rehydrated. To study rehydration we used a dual channel, fast cycle apparatus to simulate in vivo oxy/deoxy conditions. A 1% suspension of dense (>1.107 g/cc) SS RBC was cycled through gas permeable silicone tubing in a continuous, closed circuit. Each channel contained deoxygenator and oxygenator sections in which pO2 was measured continuously (35.0+-8.6 mmHg and 71.8+-15.6 mmHg). Circuit time was 72.8+-2.0 seconds and total cycling time was 97.4+-10.9 minutes. After cycling, the cells were separated by density and the generation of light cells (<1.087 g/cc) quantified. Statistical comparison were paired t-tests with concurrent controls. There was some light cell generation during static incubations at 37C (1.6+-1.2%, n=8). Fast oxy/deoxy cycling produced a significant increase in light cell formation (9.5+-5.7%, n=8, p<0.004). The rehydrated cells were K depleted (22.7+-21.3 mM/KgHb, n=5) and Na loaded (368.1+-100.8 mM/KgHb, n=5). The presence of 1.5 mM external Ca++ significantly inhibited the formation of rehydrated SS RBC (4.3+-2.8% with Ca++ vs. 9.5+-5.7% without, n=8, p<0.02) during oxy/deoxy cycling. Pre-incubation of the dense cells with 45 mM DIDS, an inhibitor of deoxygenation-induced (DI) cation flux and chloride conductance, significantly inhibited the generation of light cells during fast oxy/deoxy cycling (2.2+-1.0% with DIDS vs. 3.6+-1.3% without, n=7, p<0.004). Finally, the presence during cycling of 1 mM bumetanide, which inhibits increased cation fluxes in light sickle cells, also decreased light cell formation (4.6+-2.6% with bumetanide vs. 7.2+-3.9% without, n=7, p<0.029). These findings support the hypothesis that older, low-density SS RBC derive from dense SS RBC. Inhibition of light cell generation by DIDS suggests that the DI pathway, previously implicated in SS RBC dehydration, may also be involved in rehydration of dense, K depleted cells. Inhibition of light cell generation by Ca++ is consistent with the reduction of DI Na influx by Ca++ reported previously. Alternatively, Ca++ inhibition of cycling-dependent SS RBC rehydration may represent a competition between rehydrating pathway(s) and the K(Ca) dehydrating pathway.

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Other references

Bowman, D.M.J.S.; Kirkpatrick, J.B., 1986: Establishment suppression and growth of eucalyptus delegatensis in multiaged forests iii. intraspecific allelopathy competition between adult and juvenile for moisture and nutrients and frost damage to seedlings. Field and pot experiments were designed to test the relative roles of allelopathy, competition for moisture and competition for nutrients in the suppression and growth of Eucalyptus delegatensis. In pot experiments litter cover was associated with...

Maass, K.; Fischer, M.André.; Seiler, M.; Temmerman, K.; Nickel, W.; Seedorf, M., 2009: A signal comprising a basic cluster and an amphipathic alpha-helix interacts with lipids and is required for the transport of Ist2 to the yeast cortical ER. The yeast integral membrane protein Ist2 is encoded by a bud-localised mRNA and accumulates at patch-like domains of the cell periphery, either at the cortical ER or at ER-associated domains of the plasma membrane. Transport of IST2 mRNA and local...

Fu, R.; Qian, X-Hong.; Cheng, S-Quan.; Wu, H-Jie.; Shi, Z-Ling.; Liu, Y-Dong., 2013: Upper gastrointestinal bleeding and hyperglycemia induced by acute alcoholism in an infant. Zhongguo Dang Dai Er Ke Za Zhi 14(9): 713-714

Chubareva, L.A.; Petrova, N.A., 2004: Characteristic features of karyotypes in common species of blackflies (Diptera, Simuliidae) from the northwestern region of Russia. Karyotypes of 31 blackfly species of 19 genera from the northwestern region of Russia were studied based on squashed aceto-orsein preparations of polytene chromosomes of salivary larva glands, mitotic chromosomes of gonads and ganglia. A karyotype...

Crockett, D.J., 1973: Mycetoma. This account includes details of clinical features, diagnosis, bone involvement and treatment, with special reference to the disease in Africa. The map illustrates mycetoma zones in N. Africa.

King K.C.; Kalhan S., 1986: Feeding induced gastric inhibitory polypeptide and insulin responses in preterm infants. Pediatric Research 20(4 PART 2): 413A

Parish, C., 2001: Behind the news. IF YOU only had access to the mass media, you could be forgiven for thinking that Creutzfeldt Jakob disease (CJD) equals mad cow disease in humans.

Yang, C.; Li, G.; Fang, J.; Liu, H.; Yang, B.; Xu, Y., 2016: Spinal Intramedullary Syphilitic Gumma: An Unusual Presentation of Neurosyphilis. Spinal syphilitic gumma is an unusual presentation of neurosyphilis, with a limited number of cases reported in the literature. Owing to its extreme rarity, the diagnosis and treatment of spinal syphilitic gumma and the relevant prognosis have not...

Frand, M.N.; Honig, K.L.; Hageman, J.R., 1998: Neonatal cardiopulmonary resuscitation: the good news and the bad. Many health care professionals all over the world have been taught neonatal cardiopulmonary resuscitation (CPR) using the neonatal CPR course based upon the work of Bloom and Cropley. The purpose of this article is to provide a retrospective revie...

Seyfert U.T., 1987: F dimers and diabetes mellitus type ii. Vasa Supplementum (20): 244-246