H+ buffering and excretion in response to acute hypercapnia in the dogfish Squalus acanthias

Abstract

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

Carbonic anhydrase and acid–base regulation in fish

“…Thus, the requirement to produce acidic urine to prevent the formation of precipitates may not be as strict as originally thought. Unlike in teleosts, the kidney of elasmobranchs appears to produce urine of fixed acidity regardless of the prevailing blood acid-base status (Hodler et al, 1955;Cross et al, 1969;Swenson and Maren, 1986). …”

Renal expression and localization of SLC9A3 sodium/hydrogen exchanger and its possible role in acid-base regulation in freshwater rainbow trout (Oncorhynchus mykiss)

“…Although the gill is the major site of acid-base equivalent fluxes in fish, the kidney may also contribute significantly to net acid-base excretion during periods of pH compensation, although the extent of renal involvement varies with species, type (respiratory vs. metabolic) of acid-base disturbance, and external salinity (freshwater vs. seawater) (7,8,10,12,24,28,29,36,43,45,46). The prevailing view is that, during respiratory acidosis, renal acid output in freshwater teleosts, although increased (7,37,43,46), is but a minor contributor to whole body acid excretion.…”

Renal function and acid–base regulation in two Amazonian erythrinid fishes: Hoplias malabaricus, a water breather, and Hoplerythrinus unitaeniatus, a facultative air breather

“…In spite of the very different natures of the animals, the present two Amazonian erythrinids, the marine dogfish (Cross et al 1969), and the standard man (Altman and Dittmer 1972;Pitts 1974) all exhibit very similar rates of urinary acid efflux on a weight-adjusted basis (Table 8). For the erythrinids and the dogfish, the ratios of acid excretion to metabolic rate are about the same, whereas for man the ratio is much lower, owing to the higher metabolic rate.…”

“…blood pH, for example during chronic hypercapnic acidosis, shorter term adjustments being achieved mainly by ventilation and shifts in intracellular and extracellular buffer stores (Davenport 1974). In elasmobranchs, the kidney has been shown to contribute to steady-state acid excretion, but exhibits a negligible response to acute experimental acidosis (Cross et al 1969). So far, all that is known about any possible acid-base role of the teleost kidney is that the urine pH tends to be somewhat below that of the blood (Hickman and Trump 1969), and decreases further after hypoxic stress (Hunn 1969), but without information on buffering capacity, total acidity, etc., one cannot assess the contribution of the urine to acid excretion.…”