Freshwater Rainbow Trout Research Articles

Adrenergic control of branchial chloride transport in the isolated perfused head of the freshwater trout (Salmo gairdneri)

1. The isolated, saline-perfused head of the freshwater rainbow trout (Salmo gairdneri) was used to investigate adrenergic control of branchial chloride transport. 2. Perfusing only with physiological saline (no catecholamines present) resulted in extremely low values of chloride influx (J iCl−) which approached zero with time. 3. By perfusing with a range of sympathetomimetics and adrenergic antagonists, it was demonstrated that branchial chloride influx was enhanced by alpha receptor stimulation and inhibited by beta receptor stimulation. 4. It is proposed that the effects of catecholamines onJ iCl− are specific in nature and not due to accompanying haemodynamic alterations. 5. From the results of these experiments, together with previous knowledge of adrenergic effects on branchial Na+/H+ (NH 4 + ) exchange, it is possible to postulate a scheme for piscine acid-base regulation involving altered rates of Cl−/HCO 3 − and Na+/H+ (NH 4 + ) exchanges, both a result of adrenergic stimulation.

SALMONID MARINE REARING IN FRANCE

ABSTRACTIn a preceding paper in 1980, the status of marine salmonid rearing in French coastal waters was described and the prospects analyzed. After a period of rapid increase in production (1976–1980) a plateau was reached, and in 1983 total marketed production remained below 450 metric tons. The major part of this production was composed of rainbow trout, with coho salmon and brown trout staying at a limited scale. The causes of this evolution and the possible ways of influencing further development of this activity are discussed. Among the major factors influencing production, environmental parameters (temperature, salinity), availability of juveniles, production costs of the marine phase and market acceptability are analyzed. We include a discussion about competition with marine aquaculture products of northern Europe and the emerging production of large size rainbow trout in freshwater in southern areas of France. The major inputs to be expected from research progress and their applicability to the production phase are discussed.

The mechanisms of acid-base and ionoregulation in the freshwater rainbow trout during environmental hyperoxia and subsequent normoxia. II. The role of the kidney

Plasma ionic status and renal excretion of acidic equivalents and electrolytes were continuously monitored in the freshwater rainbow trout ( Salmo gairdneri) during 24 h normoxia ( P I O2 = 120–150 torr; control) 72 h hyperoxia ( P I O2 = 500–600 torr), and 24 h return to normoxia. Plasma [Cl −] progressively declined in approximate equivalence to the rise in [HCO 3 −] which compensated the respiratory acidosis of hyperoxia, while [Na +] increased only slightly. [Ca 2+] and [K +] rose, [phosphate] declined, and [NH 4 +] was unchanged. During normoxic recovery, the [Na +], [Cl −] and [HCO 3 −] changes were reversed, [K +] and [Ca 2+] showed further elevations, and [NH 4 +] increased sharply. Renal acid output increased greatly during hyperoxia with elevations in both NH 4 + and titratable components, though the latter predominated due to a marked elevation of phosphate excretion. Renal efflux rates of other electrolytes were generally homeostatic for ECF composition, with increased Na +, K +, and Ca 2+ effluxes, and decreased Cl − efflux.Clearance calculations indicated that net tubular reabsorption increased for Cl −, fell for Na + and K +, and changed over to marked net secretion for phosphate, while net ammonia secretion increased. Most tends were reversed upon return to normoxia. The critical role of phosphate in urinary electrolyte balance and acid-base regulation is emphasized. The net renal excretion of acidic equivalents accounted for only 7–10% of the total compensation observed for the whole animal during hyperoxia. The kidney contributed primarily in conserving ECF HCO 3 − and secondarily in balancing branchial exchanges.

The mechanisms of acid-base and ionoregulation in the freshwater rainbow trout during environmental hyperoxia and subsequent normoxia. III. Branchial exchanges

Fluxes of both acidic equivalents (J net H+) and electrolytes across the gills were continuously monitored in the freshwater rainbow trout ( Salmo gairdneri) during 24 h normoxia ( P I O 2 = 120−150 torr; control) , 72 h hyperoxia ( P I O 2 = 500−600 torr ), and 24 h return to normoxia. A highly negative J net H+ ( i.e., excretion) was responsible for over 90% of the compensation of respiratory acidosis induced by hyperoxia in the whole animal. Similarly, a highly positive J net H+ ( i.e., uptake)_accounted for virtually all the compensation of metabolic alkalosis induced by normoxic recovery. Hyperoxia was associated with a small net gain of Na + and large net losses of Cl − at the gills, while normoxic recovery was associated with large net losses of Na + and net gains of Cl −, effects reflected in ECF composition. Unidirectional flux analyses with radiotracers ( 22Na, 36Cl) demonstrated that these net flux alterations resulted from rapid and complex changes in both influx and efflux components such that the difference between J net Na+ and J net Cl− was stoichiometrically equivalent to J net H+. The results support the concept that Na + vs acidic equivalent (H +, NH + 4) and Cl − vs basic equivalent (HCO 3 −, OH −) exchanges at the gill are dynamically adjusted in order to correct internal acid-base disturbances.

The mechanisms of acid-base and ionoregulation in the freshwater rainbow trout during environmental hyperoxia and subsequent normoxia. I. Extra- and intracellular acid-base status

The extracellular acid-base status of the freshwater rainbow trout ( Salmo gairdneri) was continuously monitored during 24 h normoxia ( P I O2 = 120–150 torr ; control), 72 h hyperoxia ( P I O2 = 500–600 torr) torr) and 24 h return to normoxia. Hyperoxia induced a marked respiratory acidosis ( † pHe = −0.23 unit) due to a 3-fold elevation in arterial CO 2 tension which was completely compensated over 72 h by a comparable rise in plasma bicarbonate, reflecting effective removal of acidic equavalents from the ECF. Upon return to normoxia, arterial CO 2 tension rapidly returned to normal against a background of high plasma bicarbonate, provoking a metabolic alkalosis which was largely compensated by 24 h. This effective restoration of acidic equivalents in the EXF occurred more rapidly than the original removal. Intracellular acid-base status was measured during normoxia and after 72 h hyperoxia using the steady state distribution of 14C-DMO. The rate of 14C-DMO excretion was 0.479±0.048 (%DMO lost per hour) during normoxia, and significantly decreased with hyperoxia. A considerable overestimate of mean whole body pHi would have resulted had this not been taken into account. Whole body and white expaxial muscle were similar with a pHe - pHi gradient of ca during normoxia, and underwent identical changes during hyperoxia. Intracellular pH was completely compensated by 72 h hyperoxia as intracellular bicarbonate increased 4-fold. The overall net removal of acidic equivalents from the ICFV was approximately one half that from the ECFV, but pHe regulation did not occur at the expense of pHi regulation. The ultimate restoration of both pHe and pHi during hyperoxia must have occurred via kidney or gills.

Estimation of growth potential by measurement of tissue protein synthetic rates in feeding and fasting rainbow trout, Salmo gairdnerii Richardson

Protein synthesis in liver, gill and muscle tissue was measured in vivo by constant infusion of 14C‐tyrosine in fed and fasted freshwater rainbow trout, Salmo gairdnerii, at 12° C. Synthesis rates (percentage of tissue protein synthesized per day) were 15‐17% in liver, 4–5% in gill and 0.38% in muscle of fed fish. Liver and gill synthesis rate showed no significant change in fish that had been without food for 15 days, whereas muscle protein synthesis fell to 0.09%. The greater susceptability of muscle protein synthesis to fasting, possibly results from the greater proportion of synthesis retained as growth in this tissue. Growth rates indicate little change in protein turnover in the muscle but increased protein degradation with fasting. The difference between fed and fasted synthesis rates in muscle may be used as a measurement of potential growth rate for a particular species.

Epizootic caused by β-Haemoltytic Streptococcus Species in Cultured Freshwater Fish

Streptococcal infections have been frequently observed in cultured freshwater fish, tilapia (Tilapia nilotica), rainbow trout (Salmo gairdneri) and ayu (Plecoglossus altivelis) at farms in various districts of Japan. The causative agents isolated from diseased tilapia, rainbow trout and ayu had the same morphological as well as biochemical characteristics. All the strains were also serological homogeneous. These strains were found to be pathogenic to freshwater fish after intraperitoneal injection. The autoclaved and hot-HCl treated cells did not react with any of the group specific sera used: Lancefield A, B, C, D, E, F, G, H, K, L, M, N, O and MG. This organism was not identical to any strains of Streptcoccus previously reported.

The response of the kidney of the freshwater rainbow trout to true metabolic acidosis.

Infusion of lactic acid into the bloodstream of trout produced a short-lived depression of blood pH and a long-lasting elevation of blood lactate. The lactate injected was distributed in a volume of 198 ml/kg. Renal excretion of lactate anion and total acid increased by approximately equal amounts during the period of high blood lactate levels, but total renal loss over 72 h accounted for only 2% of the lactate load and 6% of the proton load. Comparable differences in the time courses of blood lactate and pH changes occurred when lactacidosis was induced endogenously by normocapnic hypoxia. The immediate response of the kidney was similar to that with lactic acid infusion, but there was a long-lasting (12-72 + h) elevation of urinary acid efflux that was not associated with lactate excretion. Following hypoxia, renal excretion over 72 h accounted for 1% of the estimated lactate load and 12-25% of the proton load. A renal lactate threshold of 4-10 muequiv/ml prevents significant urinary lactate excretion. The response of the trout kidney to true metabolic acidosis is similar to that of the mammalian kidney.

The effect of increased metabolic rate on renal function in the rainbow trout, Salmo Gairdneri.

1. A highly significant linear correlation was found between glomerular filtration rate and urine flow rate in both freshwater and seawater trout. The percentage tubular reabsorption of water was approximately 33% greater in seawater trout than in freshwater trout. 2. As oxygen consumption increased, the urine flow rate increased in freshwater and seawater rainbow trout. The proportional increase in urine flow with incremental changes in oxygen consumption was approximately the same in fresh water and sea water. 3. A significant positive linear relationship between oxygen consumption and glomerular filtration rate was found in both salinities. The proportional increase in GFR with incremental changes in the oxygen consumption rate was higher in the seawater trout than in the freshwater trout. 4. As oxygen consumption increased, the percentage tubular reabsorption of water decreased in the freshwater trout. No significant relationship between these two factors was found in the seawater trout.

Effect of hyperosmolality on vascular resistance and lymph flow in the cat ileum.

ARTICLESEffect of hyperosmolality on vascular resistance and lymph flow in the cat ileumS. E. Levine, D. N. Granger, R. A. Brace, and A. E. TaylorS. E. Levine, D. N. Granger, R. A. Brace, and A. E. TaylorPublished Online:01 Jan 1978https://doi.org/10.1152/ajpheart.1978.234.1.H14MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByContinuous gastric saline perfusion elicits cardiovascular responses in freshwater rainbow trout (Oncorhynchus mykiss)7 October 2021 | Journal of Comparative Physiology B, Vol. 192, No. 1Lymphatic Vessels and Their Surroundings: How Local Physical Factors Affect Lymph Flow11 December 2020 | Biology, Vol. 9, No. 12Fluid Osmolarity Acutely and Differentially Modulates Lymphatic Vessels Intrinsic Contractions and Lymph Flow5 July 2018 | Frontiers in Physiology, Vol. 9Seawater acclimation affects cardiac output and adrenergic control of blood pressure in rainbow trout ( Oncorhynchus mykiss )—implications for salinity variations now and in the future22 November 2018 | Conservation Physiology, Vol. 6, No. 1Systemic and splanchnic hemodynamic effects of intravenous hypertonic glucose in patients with cirrhosisHepatology, Vol. 8, No. 3 More from this issue > Volume 234Issue 1January 1978Pages H14-H20 Copyright & PermissionsCopyright © 1978 the American Physiological Societyhttps://doi.org/10.1152/ajpheart.1978.234.1.H14PubMed637909History Published online 1 January 1978 Published in print 1 January 1978 Metrics

Endocrine effects on nitrogen excretion in the euryhaline teleost, Salmo gairdnerii

Several of the hormones known to be active in the induction of parr-smolt transformation and the migration of salmonids to salt water were administered to nonsmolt freshwater rainbow trout to assess their effects on the nitrogen excretion of fed and starved individuals. Somatotrophin and thyroxine decreased nitrogen excretion in the fed fish, whereas cortisol was without effect. In the starved fish, cortisol caused an increase in the excretion of nitrogen, but somatotrophin and thyroxine were ineffective. Simultaneous administration of cortisol and somatotrophin to nonsmolt freshwater fish produced a pattern of nitrogen excretion similar to that observed in freshwater smolt and salt water fish, decreasing the nitrogen excretion of fed fish but inducing an increase in starved fish. It is suggested that the hormones responsible for the regulation of euryhalinity in rainbow trout have an important influence on the different specific growth and nitrogen excretion rates found at the various stages in its life history.

Experimental and structural analysis of the function of saccus vasculosus in rainbow trout, Salmo gairdneri (Richardson).

Injection of a saccus vasculosus homogenate from sea water adapted rainbow trout into the third brain ventricle of fresh-water rainbow trout increased the survival time of the latter in sea water of high salinity. This indicated an active role of saccus vasculosus in osmoregulation.

Effect of amiloride on sodium transport across body surfaces of freshwater animals.

Effect of amiloride on sodium transport across body surfaces of freshwater animals.

Acidification of urine by the isolated urinary bladder of the toad.

Acidification of urine by the isolated urinary bladder of the toad.

Gas Exchange in Rainbow Trout (Salmo gairdneri) with Varying Blood Oxygen Capacity

The effects of large changes in hemoglobin concentration were studied in rainbow trout in fresh water between 8 and 14 C. Anemia was produced by injecting phenylhydrazine hydrochloride or by replacing blood with either saline or plasma.No significant changes were observed in the rate of oxygen consumption, arterial or venous oxygen tensions, ventilation volume, inspired and expired water oxygen tensions, or dorsal aortic blood pressure. The primary compensatory mechanism invoked was an increase in the cardiac output, which was accomplished almost entirely by increases in stroke volume. Although the viscosity of the blood was reduced, there must also be large changes in the peripheral resistance to blood flow, since greatly increased cardiac output was achieved without significant increase in blood pressure.The change in blood oxygen capacity and increase in cardiac output caused significant lowering of the ventilation–perfusion ratio, but the capacity–rate ratio of water to blood varied only a little. A small rise occurred at low hematocrit values, due to small changes in a number of parameters.The experiments illustrate what happens when blood oxygen capacity is reduced, but do not elucidate the mechanism for control of stroke output of the heart. They also indicate that a species' hemoglobin level is maintained at a level that allows cardiac output to vary over an optimal range of its efficiency curve.

Effect of temperature and hemoglobin concentration on solubility of O2 in blood.

Effect of temperature and hemoglobin concentration on solubility of O2 in blood.

Intracellular pH.

Intracellular pH.

Intestinal blood flow during perfusion of the jejunum with hypertonic glucose in dogs.

ARTICLESIntestinal blood flow during perfusion of the jejunum with hypertonic glucose in dogsPD Van Heerden, Wagner HN Jr, and S KaiharaPD Van Heerden, Wagner HN Jr, and S KaiharaPublished Online:01 Jul 1968https://doi.org/10.1152/ajplegacy.1968.215.1.30MoreSectionsPDF (856 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformationCited ByContinuous gastric saline perfusion elicits cardiovascular responses in freshwater rainbow trout (Oncorhynchus mykiss)7 October 2021 | Journal of Comparative Physiology B, Vol. 192, No. 1Possibility of enteral correction of posthemorrhagic disturbances depending on state of the absorptive function of the small intestineBulletin of Experimental Biology and Medicine, Vol. 110, No. 1Microcirculation of the intestinal mucosa1 January 2011Small-volume resuscitationBaillière's Clinical Anaesthesiology, Vol. 2, No. 3Systemic and splanchnic hemodynamic effects of intravenous hypertonic glucose in patients with cirrhosisHepatology, Vol. 8, No. 3The radiolabeled microsphere technique in gut blood flow measurement—Current practiceJournal of Surgical Research, Vol. 37, No. 3CIRCULATORY RESPONSES TO CHANGES OF INTESTINAL CONTENTSIntestinal blood flowGastroenterology, Vol. 78, No. 4Effect of altered intestinal water transport on rabbit ileal blood flow.M Donowitz, D Wicklein, D G Reynolds, R A Hynes, A N Charney, and M J Zinner1 April 1979 | American Journal of Physiology-Endocrinology and Metabolism, Vol. 236, No. 4Enterocyte turnover and content in fat-fed hamstersThe American Journal of Digestive Diseases, Vol. 23, No. 6Intestinal responses to hyperosmolar glucose infusion in dogsGastroenterologia Japonica, Vol. 12, No. 2Results of Treatment of Experimental Pulmonary Embolism, as Determined By Radioactive Microspheres18 August 2016 | Vascular Surgery, Vol. 9, No. 2Herstellung markierter sphärischer Teilchen aus Humanserumalbumin im Gröβenbereich von 0,3–3 μm für die Untersuchung des retikuloendothelialen Systems9 September 2008 | Isotopenpraxis Isotopes in Environmental and Health Studies, Vol. 9, No. 3Effect of bethanidine on placental blood flow in conscious rabbitsAmerican Journal of Obstetrics and Gynecology, Vol. 111, No. 3Blood Flow and Gastrointestinal FunctionGastroenterology, Vol. 60, No. 2Pressure-Dependent Heterogeneity of Renal Cortical Blood Flow in DogsCirculation Research, Vol. 27, No. 4Preparation of metabolizable radioactive human serum albumin microspheres for studies of the circulationThe International Journal of Applied Radiation and Isotopes, Vol. 21, No. 3 More from this issue > Volume 215Issue 1July 1968Pages 30-33 Copyright & PermissionsCopyright © 1968 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1968.215.1.30PubMed5659339History Published online 1 July 1968 Published in print 1 July 1968 Metrics

THE EFFECT OF ADRENOCORTICAL STEROIDS ON THE TISSUE ELECTROLYTE COMPOSITION OF THE FRESH-WATER RAINBOW TROUT (SALMO GAIRDNERI)

SUMMARY The effects were studied of cortisol, corticosterone and aldosterone on the concentrations of sodium and potassium in muscle and blood plasma and on water content of muscle in the fresh-water rainbow trout (Salmo gairdneri). These steroids appeared to cause a loss in plasma sodium throughout the 96 hr. experimental period. An initial rise in muscle sodium was observed during the first 24 hr. after commencement of the treatments. The subsequent decline in muscle sodium was interrupted by a transient rise followed by a continuing decline. The effect of these hormones on the potassium concentrations in plasma was variable, although there was a significant rise in the potassium concentration in muscle during the period of decline in sodium concentration. The significance of these results in relation to the possible enhanced adrenocortical activity of the trout during adaptation to a marine environment is discussed.

The Population and Movement of Fish in Prickley Pear Creek, Montana

Abstract A 2-year study was made on the populations and movements of fish in Prickley Pear Creek, Montana. The most numerous species present were freshwater sculpins, brown trout, rainbow trout, and longnose suckers. The number of brown trout was higher in 1949 than in 1950. Their number in relation to all trout was approximately 60 percent in 1949 and 54 percent in 1950. However, their weight in relation to that of all trout was approximately 74 percent in 1949 and 73 percent in 1950. Rainbow trout made up most of the remainder of the salmonid population. The number of trout in relation to all fish was approximately 79 percent in both years and their weight approximately 58 percent in 1949 and 47 percent in 1950. Weights of the trout remained relatively constant for the sampling periods each year but showed a significant difference between years. Suckers were numerous in the first sampling periods of each year but decreased sharply in the late summer months. The total weights of all fish varied from 58.8...