The oxygen-binding properties of the blood of the cephalopods Todarodes sagittatus, Loligo vulgaris, Architeuthis monachus, and Octopus vulgaris were studied in relation to temperature and pH. The data obtained at pH 7.4 were compared with previously reported data on nine species of cephalopod over the actual range of temperatures at which the animals live in an attempt to define the role of temperature as an effector in the process, and to demonstrate the extent to which temperature influences the ecological range of the various species.For most cephalopods we found Bohr and Haldane factors of lower than -1.0, a result that implies that the Bohr shift does not facilitate the unloading of 02, but may improve the loading of O2 with increased ventilation. The functional significance of the Bohr and Haldane effects appears, thus, to involve stabilization of pH by the isohydric transport of COz.Our results further demonstrated a significant decrease in oxygen affinity with temperature for all cephalopods studied. This relationship was more pronounced for the cephalopods from colder waters than for those from the tropics. Furthermore, a significant increase in cooperativity with decreasing affinity for oxygen was found when we compared these oxygen-binding parameters at pH 7.4 and at the temperatures of the natural habitats of the various cephalopods. The respective relationships between the Hill coefficient (ns0) and the oxygen tension at half-saturation (P5,,) allowed us to separate the cephalopods into three distinct groups: 1) the Sepia species; 2) all the squids except Architeuthis; and 3) all the Octopus species, plus Architeuthis and Nautilus, this third group being the most sluggish group examined. Furthermore, the most sluggish species, those in group 3, have the highest reported functional buffer capacities, 7-19 mM COz + pH-' . mM 02-', while the more active species have functional buffer capacities in the range of 4-7 mM CO, . pH-' . mM 0,-'. The relationship between P5,, and n50 optimizes the utilization of O2 over the entire range of Ps0 reported.Cephalopods are found in large numbers throughout the seas of the world. They vary in weight from a few grams to several hundred kilograms. Many of them have higher rates of aerobic metabolism than any other invertebrates of similar size in the sea, often even surpassing those of fish. However, the oxygen-carrying capacity of the hemocyanin-containing blood typically does not exceed 3 mM. Thus, the high requirement for 0 2 must be satisfied by the combination of high cardiac output and maximum utilization of the pool of O2 in the blood.The oxygen-binding properties of cephalopod blood have been studied since 1925 (Redfield et al., '25). In all reported cases the oxygen affinity 0 1989 ALAN R. LISS, INC.of the blood is very sensitive to pH. However, for no other group does the sensitivity to pH, expressed by the Bohr shift, show such a great variability; it ranges from -0.2 for Nautilus pompilius (Johansen et al., '78) to about -2.0 for Loligo pealei (Re...
The exposure of blood to an artificial surface such as the haemodialysis membrane results in the nearly instantaneous deposition of a layer of plasma proteins. The composition of the protein layer profoundly influences all subsequent events, and to a large extent determines the biocompatibility of the biomaterial. In the present study, we examine the protein adsorption capacity and coagulation profiles of the polysulfone-based helixone material in comparison to cellulose triacetate. A differential profiling investigation using shotgun proteomics data-independent analysis was applied to eluates obtained with each membrane after a dialysis session, in order to assess the function of desorbed proteins. Functional classification and network analysis performed using bioinformatics tools shed light on the involvement of adsorbed proteins into important molecular processes, such as lipid transport and metabolism, cell growth differentiation and communication, and the coagulation cascade. The collected evidence was further validated by targeted mass spectrometry using selected reaction monitoring on proteotypic transitions of key protein effectors, confirming the different panels of adsorbed protein on each membrane. The coagulation profile during haemodialysis of patients under polysulfone-based helixone filter cartridges was also assessed showing a slightly higher platelet activation profile after the dialysis session. The overall collected evidence highlights a modulation of the coagulation biological pathway during haemodialysis, which is largely influenced by the biomaterial used.
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