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I. C. Potter - One of the best experts on this subject based on the ideXlab platform.
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variations in the presence of chloride cells in the gills of lampreys petromyzontiformes and their evolutionary implications
Journal of Fish Biology, 2015Co-Authors: Helmut Bartels, M Krappe, Christoph Wrede, M.m. White, Margaret F. Docker, I. C. PotterAbstract:Although confined to fresh water, non-parasitic species of lampreys and the landlocked parasitic sea lamprey, all of which were derived relatively recently from anadromous ancestors, still develop chloride cells, whose function in their ancestors was for osmoregulation in marine waters during the adult parasitic phase. In contrast, such cells are not developed by the non-parasitic least brook lamprey Lampetra aepyptera, which has been separated from its ancestor for >2 million years, nor by the freshwater parasitic species of the genus Ichthyomyzon. The length of time that a non-parasitic species or landlocked parasitic form or species has spent in fresh water is thus considered the overriding factor determining whether chloride cells are developed by those lampreys.
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circadian rhythms of activity ventilatory frequency and heart rate in the adult river lamprey Lampetra fluviatilis
Journal of Zoology, 2009Co-Authors: P N Claridge, I. C. Potter, G. M. HughesAbstract:Activity and the electrocardiogram and respiratory potentials of 17 adult River lampreys, Lampetra fluviatilis, acclimated to 7°± 1°C and a light/dark cycle of 11/13 hours, were recorded throughout the spawning run (November to April). Activity was far greater in the dark in all but the sexually mature animals, reflecting behaviour in the field. A circadian rhythm was also observed in the heart rate during periods of inactivity, and this was correlated with an increase in ventilatory frequency or amplitude. A similar rhythm was not present in the sexually mature animals. Moreover, heart and ventilatory frequencies tended to increase during the spawning run. A whole number ratio between heart rate and ventilatory frequency was seen in only 11 of 425 recordings.
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the estuarine biology of the river lamprey Lampetra fluviatilis in the firth of forth scotland with particular reference to size composition and feeding
Journal of Zoology, 2009Co-Authors: Peter S Maitland, Kenneth H Morris, K East, M P Schoonoord, I. C. PotterAbstract:Samples collected regularly during 1979, 1980 and 1981 from the intake screens of power stations in the estuary of the River Forth produced data on the estuarine phase in the life cycle of the River lamprey, Lampetra fluviatilis. Recently metamorphosed animals were common during the spring while sexually maturing adults were abundant in the late summer and autumn. These were assumed to be lampreys at the end of their downstream and start of their upstream migrations respectively. The respective sizes of the presumed downstream and upstream migrants were 69–135 mm (0-2-2-8 g) and 200–361 mm (7-0-93-2 g). Smaller numbers of animals of intermediate size were collected during the summer and late autumn. Males were usually the predominant sex with an average of 56–5% of the population in 1980–1981. In all months, the mean weight and with one exception also the mean length, was greater for females than for males. The intestine frequently contained fish remains, especially muscle, bone and scales of clupeids and thus the River lamprey seems to feed mainly on teleosts in this estuary. An analysis of the size of scales in the intestines of lampreys of various body lengths indicates that there is a relationship between the size of host and predator. Comparisons with other studies of Lampetra fluviatilis emphasize the variability that exists in aspects of the biology of this species within and among populations.
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changes in haemopoietic sites during the metamorphosis of the lampreys Lampetra fluviatilis and Lampetra planeri
Journal of Zoology, 2009Co-Authors: Richard Percy, I. C. PotterAbstract:An investigation has been made in both the parasitic lamprey Lampetra fluviatilis and in its non-parasitic derivative Lampetra planeri of the rate at which the fat column replaces the typhlosole and nephric fold as the principal site of haemopoiesis. In the typhlosole, blood cell formation started to decline prior to the onset of external metamorphosis and had ceased within four weeks of the commencement of transformation. In the nephric fold haemopoiesis continued for several weeks in the region where the larval opisthonephros persisted but was never observed in the newly developing adult kidney. Soon after the onset of external metamorphosis the fat column started to become haemopoietic and later became the main site of blood cell formation. The rate at which the haemopoietic function was transferred from the nephric fold and typhlosole to the fat column was greater in L. fluviatilis than in L. planeri. Since a similar more rapid change in L. fluviatilis has also been found in the switch from larval to adult haemoglobin, the former type of haemoglobins may be produced only in erythrocytes originating in the nephric fold and typhlosole, whereas the latter type may be restricted to cells developed in the fat column. It is also suggested that the functional significance of the alteration in haemopoietic sites is related to changes at metamorphosis in the three regions where blood cell formation occurs.
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blood cell formation in the river lamprey Lampetra fluviatilis
Journal of Zoology, 2009Co-Authors: Lord Richard Percy, I. C. PotterAbstract:Haemopoiesis has been studied throughout the life cycle of the parasitic lamprey, Lumpetra fluviatilis, with supplementary data being provided by its nonparasitic derivative, Lampetra planeri. Attention was paid to the location of the principal haemopoietic sites in both the larval and post-larval stages and to the mode of differentiation of the blood cells. In the prolarva, the formation of blood cells takes place initially in the blood islands but, at the time when the gut starts to rotate, this role is taken over by the typhlosole. After the ammocoete has reached about 20 mm in length, division and maturation of blood cells were also clearly detected in the intertubular and fat cell region of the nephric fold. Both the typhlosole and nephric fold discharge blood cells into the circulation and throughout the rest of larval life constitute the main sites of lymphopoiesis, erythropoiesis and granulopoiesis. At the beginning of transformation, however, both these structures undergo involution and by the end of metamorphosis the haemopoietic function has been assumed by the fat column. This latter organ remains active throughout the adult phase until near the end of the spawning run at which time it undergoes massive degenerative changes. Differentiation of blood cells from the fixed cells of haemopoietic tissues occurs only in the blood islands of the prolarva and in the typhlosole during the very earliest stages of its development. Throughout the rest of the life cycle, the mode of formation of blood cells was the same in haemopoietic tissues containing a reticular network (typhlosole, fat cell region of the nephric fold and fat column) as in haemopoietic tissue where there was no such fibrous arrangement (the intertubular tissue of the more ventral regions of the opisthonephric kidney). Haemopoietic tissues could be seen to be formed in all the above structures by the accumulation of immature cells in tissue spaces which form a suitable environment for cell division and maturation. Descriptions are given of lineages leading from small lymphocyte-like stem cells to erythrocytes and to eosinophilic and neutrophilic granulocytes, and from large lymphocytes to macrophages.
Michael J Conlon - One of the best experts on this subject based on the ideXlab platform.
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molecular evolution of peptide tyrosine tyrosine primary structure of pyy from the lampreys geotria australis and Lampetra fluviatilis bichir python and desert tortoise
Regulatory Peptides, 1999Co-Authors: Yuqi Wang, Per F. Nielsen, Valentine A Lance, John H. Youson, I. C. Potter, Michael J ConlonAbstract:Peptide tyrosine–tyrosine (PYY) has been isolated from the intestines of two species of reptile, the desert tortoise Gopherus agassizii (Testudines) and the Burmese python Python molurus (Squamata), from the primitive Actinopterygian fish, the bichir Polypterus senegalis (Polypteriformes) and from two agnathans, the Southern-hemisphere lamprey Geotria australis (Geotriidae) and the holarctic lamprey Lampetra fluviatilis (Petromyzontidae). The primary structure of bichir PYY is identical to the proposed ancestral sequence of gnathostome PYY (YPPKPENPGE10 | DAPPEELAKY20 | YSALR HYINL30 | ITRQRY). Tortoise and python PYY differ by six and seven residues, respectively, from the ancestral sequence consistent with the traditional view that the Testudines represent an earlier divergence from the primitive reptilian stock than the Squamates. The current views of agnathan phylogeny favor the hypothesis that the Southern-hemisphere lampreys and the holarctic lampreys arose from a common ancestral stock but their divergence is of a relatively ancient (pre-Tertiary) origin. The Geotria PYY-related peptide shows only two amino acid substitutions (Pro10→Gln and Leu22→Ser) compared with PYY from the holarctic lamprey Petromyzon marinus. This result was unexpected as Petromyzon PYY differs from Lampetra PYY deduced from the nucleotide sequence of a cDNA (Soderberg et al. J. Neurosci. Res. 1994;37:633–640) by 10 residues. However, a re-examination of an extract of Lampetra intestine revealed the presence of a PYY that differed in primary structure from Petromyzon PYY by only one amino acid residue (Pro10→Ser). This result suggests that the structure of PYY has been strongly conserved during the evolution of Agnatha and that at least two genes encoding PYY-related peptides are expressed in Lampetra tissues.
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characterization of insulin glucagon and somatostatin from the river lamprey Lampetra fluviatilis
General and Comparative Endocrinology, 1995Co-Authors: Michael J Conlon, Yurii Rusakov, Erika M Plisetskaya, Dennis C Mynarcik, Vera M Bondareva, Jonathan WhittakerAbstract:Abstract Insulin has been isolated from an extract of the pancreas of an Agnathan, the river lamprey Lampetra fluviatilis . The primary structure of the peptide (A-chain: GIVEQ CCHRK CSIYD MENYC N; B-chain: SALTG AGGTH LCGSH LVEAL YVVCG DRGFF YTPSK T) is the same as that in insulin from the sea lamprey Petromyzon marinus . In contrast, Lamperta glucagon (HAQGS FTSDY SKYLD SKQAK DFVIW LMNT), isolated from an extract of intestine, is structurally more similar to human glucagon (five amino acid substitutions) than to Petromyzon glucagon (six substitutions). Similarly, the primary structure of somatostatin (AAAAP GAAGG AQLPL GNRER KAGCK NFFWK TFSSC), isolated from Lampetra pancreas, contains eight amino acid substitutions and an additional residue compared with Petromyzon somatostatin. Somatostatin, isolated from Lampetra brain, has an identical structure to mammalian somatostatin-14 (AGCKN FFWKT FTSC). indicative of the same tissue specific expression of different somatostatin genes that was previously observed in Petromyzon . In contrast to the reduced binding affinity of other fish insulins, lamprey insulin was equipotent with porcine insulin in inhibiting the binding of [3-[ 125 I]iodotyrosine-A14] human insulin to the human insulin receptor.
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tachykinins with unusual structural features from a urodele the amphiuma an elasmobranch the hammerhead shark and an agnathan the river lamprey
Peptides, 1995Co-Authors: David Waugh, Christina Bjenning, Per F. Nielsen, Yurii Rusakov, Vera M Bondareva, Michael J ConlonAbstract:Abstract Tachykinins were purified from extracts of gastrointestinal tissues of the urodele, Amphiuma tridactylum (three-toed amphiuma), and the elasmobranch Sphyrna lewini (hammerhead shark), and from the brain of the agnathan Lampetra fluviatilis (river lamprey). The amphiuma substance P (SP) (DNPSVGQFYGLM-NH 2 ) contains 12 amino residues compared with 11 for mammalian SP and lacks the Arg/Lys-Pro-Xaa-Pro motif that is characteristic of NK 1 receptor-selective agonists. Lampetra SP (RKPHPKEFVGLM-NH 2 ) is identical to SP from the sea lamprey and the shark SP-related peptide (AKFDKFYGLM-NH 2 ) is identical to dogfish scyliorhinin I. Amphiuma neurokinin A (NKA) (HKDAFIGLM-NH 2 ) and lamprey NKA (HFDEFVGLM-NH 2 ) contain 9 amino acid residues compared with 10 for mammalian NKA. The shark NKA-related peptide (ASGPTQAGIV 10 GRKRQKGEMF 20 VGLM-NH 2 ) shows limited structural similarity to mammalian neuropeptide γ and the teleost tachykinin, carassin but contains 24-rather than 21 amino acid residues. The data show that the primary structures of the tachykinins have been very poorly conserved during vertebrate evolution and that pressure has acted only to maintain the functionally important sequence -Phe-Xaa-Gly Leu-Met-NH 2 at the COOH-termini of the peptides.
Margaret F. Docker - One of the best experts on this subject based on the ideXlab platform.
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Simple Genetic Assay Distinguishes Lamprey Genera Entosphenus and Lampetra: Comparison with Existing Genetic and Morphological Identification Methods
North American Journal of Fisheries Management, 2016Co-Authors: Margaret F. Docker, Gregory S Silver, Jeffrey C Jolley, Erin K. SpiceAbstract:AbstractSeveral species of lamprey belonging to the genera Entosphenus and Lampetra, including the widely distributed Pacific Lamprey E. tridentatus and Western Brook Lamprey L. richardsoni, co-occur along the West Coast of North America. These genera can be difficult to distinguish morphologically during their first few years of larval life in freshwater, thus hampering research and conservation efforts. However, existing genetic identification methods are time consuming or expensive. Here, we describe a simpler genetic assay using the Pacific Lamprey microsatellite locus Etr-1; the assay was found to be 100% reliable in distinguishing Entosphenus from Lampetra, even in genetically divergent Lampetra populations. Using a sample of 244 larvae (18–136 mm TL) from the Columbia River basin, we tested the accuracy with which previously described differences in caudal fin pigmentation can distinguish these genera. Attempts at morphological identification were abandoned for 50-mm and smaller larvae because diff...
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variations in the presence of chloride cells in the gills of lampreys petromyzontiformes and their evolutionary implications
Journal of Fish Biology, 2015Co-Authors: Helmut Bartels, M Krappe, Christoph Wrede, M.m. White, Margaret F. Docker, I. C. PotterAbstract:Although confined to fresh water, non-parasitic species of lampreys and the landlocked parasitic sea lamprey, all of which were derived relatively recently from anadromous ancestors, still develop chloride cells, whose function in their ancestors was for osmoregulation in marine waters during the adult parasitic phase. In contrast, such cells are not developed by the non-parasitic least brook lamprey Lampetra aepyptera, which has been separated from its ancestor for >2 million years, nor by the freshwater parasitic species of the genus Ichthyomyzon. The length of time that a non-parasitic species or landlocked parasitic form or species has spent in fresh water is thus considered the overriding factor determining whether chloride cells are developed by those lampreys.
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genetic diversity endemism and phylogeny of lampreys within the genus Lampetra sensu stricto petromyzontiformes petromyzontidae in western north america
Journal of Fish Biology, 2012Co-Authors: David A Boguski, Damon H Goodman, S B Reid, Margaret F. DockerAbstract:: Phylogenetic structure of four Lampetra species from the Pacific drainage of North America (western brook lamprey Lampetra richardsoni, Pacific brook lamprey Lampetra pacifica, river lamprey Lampetra ayresii and Kern brook lamprey Lampetra hubbsi) and unidentified Lampetra specimens (referred to as Lampetra sp.) from 36 locations was estimated using the mitochondrial cytochrome b gene. Maximum parsimony and Bayesian inferences did not correspond with any taxonomic scheme proposed to date. Rather, although L. richardsoni (from Alaska to California) and L. ayresii (from British Columbia to California) together constituted a well-supported clade distinct from several genetically divergent Lampetra populations in Oregon and California, these two species were not reciprocally monophyletic. The genetically divergent populations included L. pacifica (from the Columbia River basin) and L. hubbsi (from the Kern River basin) and four Lampetra sp. populations in Oregon (Siuslaw River and Fourmile Creek) and California (Kelsey and Mark West Creeks). These four Lampetra sp. populations showed genetic divergence between 2.3 and 5.7% from any known species (and up to 8.0% from each other), and may represent morphologically cryptic and thus previously undescribed species. A fifth population (from Paynes Creek, California) may represent a range extension of L. hubbsi into the Upper Sacramento River.
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Characterization of 12 microsatellite loci for the Pacific lamprey, Entosphenus tridentatus (Petromyzontidae), and cross-amplification in five other lamprey species.
Genetics and molecular research : GMR, 2011Co-Authors: Erin K. Spice, T.a. Whitesel, C.t. Mcfarlane, Margaret F. DockerAbstract:The Pacific lamprey (Entosphenus tridentatus) is an anadromous fish that is of conservation concern in North America and Asia. Data on Pacific lamprey population structure are scarce and conflicting, impeding conservation efforts. We optimized 12 polymorphic microsatellite loci for the Pacific lamprey. Three to 13 alleles per locus were observed in a sample of 51 fish collected from the West Fork Illinois River, Oregon. Observed heterozygosity ranged from 0.235 to 0.902 and expected heterozygosity ranged from 0.214 to 0.750. Cross-species amplification produced 8 to 12 polymorphic loci in four other Entosphenus species and in the western brook lamprey (Lampetra richardsoni). Two loci appear to be diagnostic for distinguishing Entosphenus from Lampetra. These markers will be valuable for evaluating population structure and making conservation decisions for E. tridentatus and other lamprey species.
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validity of Lampetra pacifica petromyzontiformes petromyzontidae a brook lamprey described from the lower columbia river basin
Zootaxa, 2011Co-Authors: Stewart B Reid, David A Boguski, Damon H Goodman, Margaret F. DockerAbstract:The Pacific Brook Lamprey, Lampetra pacifica Vladykov, 1973 was described from the lower Columbia River Basin near Portland, Oregon. Subsequently, L. pacifica has generally been treated as a junior synonym of the Western Brook Lamprey, L. richardsoni Vladykov and Follett, 1965, a species described from the Fraser River Drainage east of Vancouver, British Columbia. We reexamine the available morphological data used by previous authors (trunk myomere counts), report on recent collections from the Columbia Basin, and reinterpret the trunk myomere data in the context of recent genetic sampling from the same populations. Populations of L. pacifica are distinguished from those of L. richardsoni by trunk myomere counts of 53–60 (means 59), respectively, and by genetic sequence divergence (cyt b) of 2.85 to 3.20%. We find no support for placing L. pacifica in the synonymy of L. richardsoni and recognize L. pacifica as a valid species. However, we recognize that there is considerable unresolved diversity in the western North American lampreys and recommend restriction of L. pacifica to the Columbia Basin, suggesting that unresolved populations of Lampetra brook (non-parasitic) lampreys outside the basin with mean trunk myomere counts below 59 be referred to as L. cf. pacifica, until further systematic information is available.
D.s. Pavlov - One of the best experts on this subject based on the ideXlab platform.
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Feeding Habits of Larval European River Lamprey Lampetra fluviatilis from the Chernaya River (Baltic Sea Basin)
Journal of Ichthyology, 2019Co-Authors: N. V. Polyakova, A. V. Kucheryavyy, D.s. Pavlov, I. A. TsimbalovAbstract:— The results of the analysis of the bolus of the larval river lamprey Lampetra fluviatlis caught in the Chernaya River in May are presented. A quantitative analysis of the main food components is performed; the taxonomic composition of algae and invertebrates is determined. The content of the digestive tract consists mainly (>90% of weight) of sand and detritus as well as algae and invertebrates. A large amount of diatoms, other plankton, and periphyton unicellular algae and coenobia, as well as plankton rotifers, have been first found among food items. It is shown that organisms from the river flow may play a critical role in larval lamprey.
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results of hybridization between anadromous and resident forms of european river lamprey Lampetra fluviatilis
Journal of Ichthyology, 2018Co-Authors: I. A. Tsimbalov, A V Kucheryuavyi, D.s. PavlovAbstract:Survival of the progeny obtained from artificial crossing of large parasitic anadromous and small nonparasitic resident European river lampreys Lampetra fluviatilis is analyzed. A high individual survival (~61% on average) up to the stage of prolarvae burrowing into ground confirms the absence of a postzygotic barrier between the lamprey forms. The obtained results are discussed in the framework of two theories: of paired species and of intraspecies diversity.
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temporal characteristics of downstream migration of smolts of the european river lamprey Lampetra fluviatilis in the chernaya river
Biology Bulletin, 2017Co-Authors: D.s. Pavlov, A. O. Zvezdin, I. A. Tsimbalov, V. V. Kostin, A. V. KucheryavyyAbstract:Data on the seasonal and diurnal dynamics of downstream migration of smolts of the European river lamprey Lampetra fluviatilis are obtained. On the basis of published data and surveys in nature, it is shown that in the largest part of the area the downstream migration of smolts occurs mainly in spring, in the period of high water in rivers caused by snow melting. The smolts undertake downstream migration at night, under minimal illumination. It has been determined experimentally that the smolts are characterized by negative photopreferendum (>90% of smolts preferred illumination <0.4 lx).
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Biological characteristics of smolts of European river lamprey Lampetra fluviatilis from the Chernaya River basin (Gulf of Finland, Baltic Sea)
Journal of Ichthyology, 2017Co-Authors: A. V. Kucheryaviy, A. O. Zvezdin, D. Yu. Nazarov, I. A. Tsimbalov, D.s. PavlovAbstract:Smolts of European river lamprey Lampetra fluviatilis from the Chernaya River basin are described. Expansion of variation limits is suggested on the basis of comparative analysis of taxonomically significant characters of this population and the species area. Structure of gonads and intestine of specimens preparing themselves for the feeing phase of their life cycle is described and some changes during the feeding phase are reconstructed. The scheme of analysis and description of smolts is suggested, the last may be applied to other lamprey species. The term “smolt” is rightfully used for juvenile anadromous lampreys making downstream migration. Biology of parasitic nonanadromous species of lampreys during the feeding phase (juvenile postmetamorphic phase) differs from biology of smolts.
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Polymorphism of spawners of the resident form of European river lamprey Lampetra fluviatilis (Petromyzontidae)
Journal of Ichthyology, 2016Co-Authors: A. V. Kucheryavyi, A. O. Zvezdin, D. Yu. Nazarov, I. A. Tsimbalov, V. V. Kostin, D.s. PavlovAbstract:Data on polymorphism (plastic and meristic characters) are obtained for spawners of resident nonparasitic form of European river lamprey Lampetra fluviatilis from the Serebristaya River. The new data verify the diagnosis of this species and contribute to the formulation of a hypothesis on the presence of several phenotypic groups: dwarf, small-sized, and common. Analysis of plastic characters and of the number of trunk myomeres demonstrated that the values of these characters reliably depend on position of lampreys in a certain discerned group. Some aspects of biology of this species are discussed: spawning and interaction between resident nonparasitic river and migrating parasitic lampreys.
Mikko Nikinmaa - One of the best experts on this subject based on the ideXlab platform.
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volume and ph regulation in agnathan erythrocytes comparisons between the hagfish myxine glutinosa and the lampreys petromyzon marinus and Lampetra fluviatilis
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 1993Co-Authors: Bruce L Tufts, Mikko Nikinmaa, Robert G. BoutilierAbstract:The responses of hagfish (Myxine glutinosa) and lamprey (Lampetra fluviatilis and Petromyzon marinus) erythrocytes to osmotic swelling in hypoosmotic medium and to acid-base disturbances induced by ammonium chloride prepulse were studied. The erythrocytes of hagfish regulated neither cell volume after osmotic swelling nor intracellular pH after acidification. In contrast, the erythrocytes of lamprey lost potassium and chloride after osmotic swelling, whereby their volume recovered. Furthermore, the red cell pH of lamprey recovered from experimental acidification in a nominally bicarbonate-free medium in the presence of sodium, confirming that the pathway involved is sodium/proton exchange.
