Anuran amphibia which are not acclimable to high salt,tolerate high plasma urea

• 1.1. The capacity of five anuran Amphibians (Bufo viridis B. regularis, Rana ridibunda, Hyla arborea and Pelobates syriacus) to acclimate to NaCl and urea solutions was investigated.
• 2.2. All species could be acclimated to relatively high concentrations of urea solutions, while only Bufo viridis and Hyla arborea could be acclimated to 500 mOsm/kg or higher NaCl solutions.
• 3.3. The plasma urea concentration in B. viridis and H. arborea was elevated to levels over 140 mmol/1.
• 4.4. The sum of plasma sodium and chloride concentrations did not increase over 400 mmol/l in any species.
• 5.5. Urine osmolality, which was normally low, increased, but never exceeded the plasma osmolality.
• 6.6. In the urea acclimation conditions, urine electrolytes diminished, similarly in all species in this study.
• 7.7. It is concluded that anuran Amphibians can tolerate high plasma urea concentrations, but only those species which can elevate it, either through retention or net synthesis, can be acclimated to high salt solutions.

     

Effect of salinity on the osmotic,chloride, total protein and calcium concentrations in the hemolymph of the prawn Peneaus monodon (fabricius)

• 1.1. Osmolality and chloride concentrations in the hemolymph of Penaeus monodon became stable 1 day after molting in 32 ppt, while total protein and calcium concentrations remained stable throughout the molting cycle. When intermolt (≥ 36 hr postmolt) animals were transferred from control (32 ppt) to experimental (8–40 ppt) salinities, osmolality, chloride and total protein, but not calcium, concentrations in the hemolymph achieved steady state values 24–48 hr after transfer.
• 2.2. The hemolymph osmolality was a linear function (slope = 0.28) of medium osmolality at salinities between 8 and 40 ppt. It was isosmotic to seawater at 698 mOsm (10 g prawns) and 752 mOsm (30 g), and was hyperosmotic to the medium below isosmotic concentrations, and hypoosmotic to those above.
• 3.3. Hemolymph chloride concentration was isoionic to seawater at 334 mM, and was hyperregulated below isoionic concentrations, and hyporegulated to those above.
• 4.4. P. monodon maintained its hemolymph calcium concentration between 6.4 and 10 mM when medium salinities increased from 8 to 40 ppt.
• 5.5. Total protein concentration in the hemolymph was independent of medium salinity (8–40 ppt) and hemolymph osmolality (540–850 mOsm).

     

The chemical composition of the follicular fluid of the teleost Clinus dorsalis (Perciformes: Clinidae)

• 1.1. The osmolarity and pH of the follicular fluid was determined and analyses of total glucose, total lipids, total proteins, amino acids, urea, sodium and potassium carried out.
• 2.2. The mean osmolarity of the follicular fluid was found to be 325 mOsm/kg and the mean pH was 7.9.
• 3.3. The embryotrophe was rich in lipids (1092.39 mg/100 ml) and amino acids with the amino acid concentration exceeding normal values for human plasma.

     

In vivo responses in plasma osmolality,and intracellular water and solute concentrations in flounder (Platichthys flesus) heart ventricles under acclimation to fresh and sea water

• 1.1. Flounders transferred abruptly from sea to fresh water displayed a gradual decrease in plasma osmolality for 5–6 days (10–15 mOsm daily). When returned to sea water the osmolality increased to the original level within 1 day.
• 2.2. Heart ventricle cell water content remained unchanged during the acclimations, except for a temporary 1.4% reduction within the first 4 hr of sea water acclimation.
• 3.3. During acclimation to sea water intracellular K⁺ increased rapidly in parallel with plasma osmolality. During fresh water acclimation, however, cellular K⁺ decreased rapidly in the first day only, whereas plasma osmolality decreased further.
• 4.4. Cellular taurine remained unchanged during the initial 4 days of fresh water acclimation and then declined 32% within the next 3 days. Upon retransfer to sea water, cellular taurine increased gradually to its original level in the course of 7 days.

     

Induction of locomotor behavior in the giant African snail,Achatina fulica

• 1.1. The locomotor-inducting factor of the giant African snail, Achatina fulica, was examined.
• 2.2. Snails showed nocturnal circadian behavior in relative humidity at least over 50%. Although the rhythmicity was independent of light and darkness, it was disturbed easily by hydration, and hydrated snails continued to locomote throughout the day. For induction of locomotor behavior, relative humidity over 50% was the fundamental factor and water is shown to be the limiting factor for the endogeneous circadian oscillator.
• 3.3. The integument of snails showed a higher water permeability. Through the integument, hemolymph osmolality changed easily according to hydration and dehydration from about 120 to 400 mOsm/kg H₂O. Circadian behavior was induced in snails in which hemolymph osmolality ranged from about 130 to 230 mOsm/kg H₂O.
• 4.4. By hydration, hemolymph osmolality in quiescent and estivated snails which have higher osmolality decreased gradually and then they began to locomote according to the degree of dilution, and vice versa. The induction of behavior in these snails was controlled by low hemolymph osmolality.
• 5.5. Together with the endogeneous rhythmicity, water environment was shown to be the key factor for the induction of locomotor behavior.
• 6.6. Based on these results, the mechanisms of the induction of locomotor behavior in terrestrial pulmonates are proposed.

     

Effects of extracellular environments on the motility of spermatozoa in several marine sculpins with internal gametic association

• 1.1. The motility of spermatozoa in several marine sculpins, which exhibit a special reproductive manner of the internal gametic association, was measured in various artificial solutions, ovarian fluid and seminal plasma.
• 2.2. In the elkhorn sculpin, Alcichthys alcicornis, spermatozoa showed high motility in solutions of 300 to 400 mOsm/kg, containing sodium ion, with pH higher than 7.5, which coincided with the nature of ovarian fluid of the fish.
• 3.3. Spermatozoa of sunrise sculpin, Pseudoblennius cottoides, and elegant sculpin, Bero elegans, were motile at osmolalities isotonic to the ovarian fluid but not at osmolalities higher than 500 and 800 mOsm/kg, respectively, indicating that the gametic association in these fish is carried out exclusively in their ovaries.
• 4.4. Spermatozoa of littledragon sculpin, Blepsias cirrhosus, were motile at osmolalities higher than 300 mOsm/kg, but not in sea water, suggesting an internal gametic association to occur in this species of sculpins.
• 5.5. The results indicate that spermatozoa of the marine sculpins with the internal gametic association show their motility in environmental conditions appropriate to respective reproductive modes.

     

The effect of osmotic and ion-osmotic stresses on the blood and urine composition and urine flow of rainbow trout (Salmo gairdneri)

• 1.1. Changes in urine and plasma concentrations (sodium, potassium, magnesium, calcium and total osmotic) and urine production were determined in fish exposed to various concentrations of an ionically active substance, sodium chloride, and a non-electrolyte, mannitol, as well as freshwater.
• 2.2. Responses occurred for the most part over a short crisis period preceeding establishment of new stable conditions.
• 3.3. It was shown that plasma homeostasis was not maintained in response to changing ion-osmotic and osmotic gradients.
• 4.4. Urinary osmotic and ionic concentrations were unaffected and urine production was shown to be inversely related to the external concentration.
• 5.5. It is suggested that ionic shifts between body compartments are an important aspect of ion-osmotic adaptation.

     

Water loss and haemolymph osmolarity of Potamon potamios,an aquatic land crab,under stress of dehydration and salinity

• 1.1. Small crabs survived over 18% water loss and large crabs 21% when in dry air. Size, temperature and relative humidity affected this rate.
• 2.2. Haemolymph osmolarity of newly collected crabs ranged from 530 to 630 mOsm/kg, depending on their size and the season.
• 3.3. When dehydrated, haemolymph osmolarity rose to over 700 mOsm/kg, and ion concentration increased by over 10%.
• 4.4. Crabs survived in sea-water for at least two weeks. Haemolymph osmolarity rose and ion concentration increased. The acclimation pattern affected the haemolymph osmolarity.

     

Electrolyte changes,cell volume regulation and hormonal influences during acclimation of rainbow trout (Salmo gairdnerii) to salt water

• 1.1. Rainbow trout were acclimated to salt water (1.5, 2.0 or 3.0%, which means 40, 60 or 85% concentrated sea-water) and the electrolyte, glucose and cortisol concentrations of the plasma as well as the extra- and intracellular muscle space, the muscle electrolyte concentrations and the ATPase activity were analysed.
• 2.2. Plasma osmolality, Na⁺, Ca²⁺ and Mg²⁺ concentrations of the plasma had a maximum at 24 hr after the start of acclimation when acclimated to 3.0% salt water. Plasma osmolality, Na⁺ and Mg²⁺ concentrations were significantly higher during the whole acclimation time when exposed to 3.0% salt water.
• 3.3. Variations and regulations of ECS and ICS were clearly demonstrated. The intracellular electrolyte concentrations were also maximal at 24 hr.
• 4.4. The plasma glucose level was just slightly elevated, but the cortisol level clearly indicated a stress response at 24 hr.
• 5.5. The activity of gill Na-K-ATPase increased during the acclimation time.
• 6.6. The regulatory processes in trout during acclimation to salt water are compared with those occurring in tilapia and carp.

     

Effects of l-canavanine on arginine catabolism in manduca sexta (sphingidae: lepidoptera)

• 1.1. Hemolymph ornithine concentrations in tobacco horn worm larvae fed a 2.5 mM l-canavanine plus 25 mM l-arginine-supplemented artificial diet (CAAM) were higher than those in larvae fed diets supplemented with 2.5 mM canavanine (CAV), 25 mM arginine (ARG), or controls (CON).
• 2.2. Ornithine concentrations in CAV-treated larvae were significantly greater than the control or ARG treatment, but less than the CAAM treatment during the latter part of the wandering larval stage and during the pharate pupal stage.
• 3.3. Urea concentrations were greater during the active feeding stage with the CAAM- and ARG-treated larvae having significantly higher levels than control or CAV-treated larvae.
• 4.4. Urea concentrations in all treatments never exceeded 36.5% of the ornithine concentration.
• 5.5. Canavanine concentrations were higher in CAV-treated larvae than in CAAM-treated larvae.
• 6.6. During active feeding, arginine concentrations for all treatments were similar, but were lower in CAV- and CAAM-treated larvae during the pharate pupal stage.

     

The effect of reduced salinity on tissue and plasma composition of the dogfish,Squalus acanthias

• 1.1. Dogfish (Squalus acanthias) were acclimated to reduced salinities and their plasma, muscle tissue and erythrocytes subsequently analysed.
• 2.2. Decrease in the osmolarity of the plasma was principally due to a fall in urea concentration and a significant fall in the concentrations of sodium and chloride.
• 3.3. Changes in the muscle and erythrocytes in dilute media were a decrease in urea, potassium, sodium and chloride concentrations.
• 4.4. The concentrations of the free amino acids in the muscle and the red blood cells decreased more than would be expected by the movements of water only.
• 5.5. The results were discussed in relation to the regulation of cellular volume and the involvement of the free amino acid pool of the tissues in this process.

     

The effects of temperature and moisture on survival capacity,cuticular permeability,hemolymph osmoregulation and metabolism in the scorpion,Centruroides hentzi (banks) (scorpiones,buthidae)

• 1.1. The temperature and water relations of Centruroides hentzi females were investigated. At 12 and 72% relative humidity (RH), the lower and upper Lt₅₀ were -4.5 and 43.7°C, and -4.7 and 45.1°C, respectively. When exposed to high temperature stress, survivorship was significantly greater under mesic conditions.
• 2.2. Cuticular water loss was higher under xeric conditions (12% RH), ranging from 0.061 mg/cm²/hr at 30°C to 0.211 at 41°C.
• 3.3. Exposure to dry air (0–5% RH) resulted in a significant increase in hemolymph osmolality: from 441 to 688 mOsm over a 5 day period.
• 4.4. Mean oxygen consumption rates increased from 161.7 mm³/g/hr at 34°C to 541.6 at 44°C. ATPase activity was significantly higher in animals acclimated and tested at 35°C.

     

Effects of lysine administration on plasma arginine and on some nitrogenous catabolites in rainbow trout

• 1.1. Rainbow trout were fed either graded levels of lysine (0.8, 1.8 and 3%) at a constant level of arginine (1.4%) or excess arginine (2.4%) at a fixed level of lysine (1.8%).
• 2.2. Increasing the dietary lysine level affected plasma urea, plasma arginine and ammonia excretion.
• 3.3. Trout fed graded levels of lysine received an arginine challenge (U¹⁴C-l-arginine) and it was found that excess dietary lysine led to a decrease in arginine degradation.
• 4.4. Injection of l-lysine induced a decrease in urea excretion, while injection of l-arginine increased both urea and ammonia excretion in control well-fed trout.
• 5.5. These results are discussed in the light of current knowledge on the antagonism between lysine and arginine.

     

Osmotic regulation in aqueous humor and blood in the euryhaline fish,Eugerres plumieri

• 1.1. The estuarine fish Eugerres plumieri was acclimated to sea-water concentrations ranging from 6 to 85% sea-water.
• 2.2. Serum and aqueous humor osmolalities were moderately well regulated over the range of concentrations studied.
• 3.3. Serum osmolality and aqueous humor osmolalities conformed to the following relations: serum osmolality = (319 ± 3) + (0.56 ± 0.03) (% sea-water); aqueous humor osmolality = (314 ± 4) + (0.35 ± 0.04) (% sea-water).
• 4.4. Aqueous humor osmolality was more strictly regulated than that of serum, indicating that the retina and nervous system of the fish, which are encased in inextensible structures, are well protected from variations in sea-water concentration in order to minimize osmotically induced changes in cell volume.

     

The effect of water loss upon the urate,urea and ammonia content of the egg of the Japanese quail Coturnix coturnix japonica

• 1.1. The urate, urea and ammonia content of the whole egg of the Japanese quail was measured in late incubation in eggs subject to different rates of water loss.
• 2.2. High rates of water loss substantially increased egg urate content, but had little or no effect on urea or ammonia content.
• 3.3. Allopurinol, an inhibitor of urate synthesis, reduced egg urate content to low levels, but produced no effect on urea content, and a small reduction in ammonia content.
• 4.4. The urea concentration of the embryo was lower than in allantoic fluid.
• 5.5. It is concluded that urate production by the avian embryo is primarily concerned with the modification of allantoic fluid composition.

     

Biochemical studies in a eunicid (polychaete) of the littoral of São Paulo,Brazil

• 1.1. The sodium, potassium, chloride, calcium, magnesium, phosphorus, sulphur, copper, iron, total carbon dioxide, uric acid, creatinine, urea, glucose, erythrocruoin, nitrogen, total iodine, protein-bound iodine, total lipids, triglycerides, alkaline phosphatase activity, acid phosphatase activity and copper oxidase activity contents of the blood of the giant Polychaete, Eunice sp., were determined.
• 2.2. The osmolarity of the blood was 997 mOsm/1 and the pH was 6·49, a very low value. The bicarbonate concentration estimated by the Henderson-Hasselbach equation was 4·70 mM/1.
• 3.3. The values of the sea water, sediments, water contained in the tube, tube, cuticle, muscle and faeces are also given.
• 4.4. The chemical composition of the mucus was determined.

     

Flight effects on certain blood parameters in homing pigeons Columba livia

• 1.1. Various blood parameters were monitored in resting and flown homing pigeons. A homing flight of 48 km lasting 60–80 min did not significantly alter plasma levels of total protein, electrolytes and plasma osmolality, which indicated maintenance of the homeostatic stability of the internal milieu during moderate exercise.
• 2.2. Plasma concentrations of marker enzymes such as alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), laetate dehydrogenase (LDH) and creatine phosphokinase (CPK) that tend to denote muscle damage and metabolic flux in prolonged exercise, were also not altered, thereby indicating the steady state of tissue structure and function during a flight of this magnitude.
• 3.3. Significant increases in plasma levels of uric acid and creatinine and decreases in plasma albumin were observed in the flown pigeons.
• 4.4. The flight-induced increase in blood uric acid could be attributed to increased purine catabolism and the increase in creatinine to increased nucleotide turnover.
• 5.5. It is suggested that the higher uric acid levels should not only enhance water conservation, but may also reduce flight-induced hyperthermia besides acting as an antioxidant defence against oxidative tissue injury.
• 6.6. The rise in creatinine is indicative of the breakdown of phosphocreatine for energy during the initial period of flight prior to the utilization of carbohydrate and lipid as fuels.
• 7.7. The decrease in plasma albumin should account for the albumin as lipid carrier lost in transport to the muscles during flight.

     

Blood volume recovery in hemorrhaged japanese quail

• 1.1. Blood volume and plasma biochemical changes and feed and water consumption in response to a hemorrhage by phlebotomy of 30% of the calculated total blood volume with and without replacement of blood volume with physiological saline were determined in juvenile male Coturnix coturnix japonica.
• 2.2. Plasma protein and osmolality decreased rapidly posthemorrhage and did not recover by 72 hr posthemorrhage.
• 3.3. Plasma glucose, Na⁺ and K⁺ increased within Ihr postphlebotomy. Plasma Na⁺ returned to nonphlebotomized levels within 6 hr postphlebotomy.
• 4.4. Saline replacement of blood volume resulted in hypervolemia within 3–5 min postphlebotomy.
• 5.5. Phlebotomized quail receiving no saline recovered blood volume to 0 hr (nonphlebotomized) levels within l hr postphlebotomy.

     

Serum and urine biochemical indicators of nutritional status in adult female collared peccaries,Tayassu tajacu (tayassuidae)

• 1.1. Physiological responses of 13 adult female collared peccaries (Tayassu tajacu) to high quality and low quality diets, fed for 15 weeks, were examined. The low quality diet simulated energy and protein intake of peccaries during poor range conditions resulting from drought. Blood samples were collected after 10 and 15 weeks of dietary treatment; urine samples were collected after 15 weeks of treatment.
• 2.2. Females receiving the low quality diet for 15 weeks lost 27.4% of their original body weight, compared to no weight change among high quality-fed females.
• 3.3. Red blood cell counts, hematocrits, and hemoglobin concentrations were significantly greater among females fed a high quality diet compared to those receiving a low quality diet. High quality-fed females also had a higher mean corpuscular hemoglobin concentration. Plasma fibrinogen concentration was nearly twice as great among females receiving the low quality diet compared to the high quality group.
• 4.4. Consumption of the low quality diet resulted in significantly elevated serum levels of nonesterified fatty acids, alkaline phosphatase, phosphorus, alpha-2 globulin and alpha globulin: beta globulin ratio.
• 5.5. Consumption of the low quality diet resulted in significantly lowered serum levels of urea nitrogen, calcium, zinc, calcium: phosphorus, urea index, beta-1 flobulin, beta globulin: albumin ratio, thyroxine and triiodothyronine.
• 6.6. Serum levels ofcreatinine, total bilirubin, glucose, cholesterol, gamma glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, potassium, copper, magnesium, sodium chloride, total protein and gamma globulin were unaffected by diet quality.
• 7.7. Urine chemistry results suggested pH, osmolarity, albumin, creatinine phosphokinase, calcium and phosphorus concentrations might be useful indices for assessing nutritional status in female peccaries.

     

Unfolding and release of heme from human hemoglobins A,S and F

• 1.1. Analysis of the Soret spectra of hemoglobins A, S and F has been used to determine the extent of heme exposure and release from these hemoglobins in the presence of several solvent perturbants.
• 2.2. Oxyhemoglobin S unfolding in the presence of either urea or propyl urea resulted in greater heme exposure and release than either oxyhemoglobins A or F.
• 3.3. Methemoglobin formation resulted in lower denaturation midpoints for each hemoglobin compared to the reduced oxyhemoglobin state; methemoglobin F had the lowest denaturation midpoint under isothermal denaturing conditions.
• 4.4. Rate of heme exposure was greater for oxyhemoglobin S than oxyhemoglobin A in the presence of 200 μM the anionic detergent sodium dodecyl sulfate.
• 5.5. Evidence for increased levels of heme release in hemoglobin S may be related to the greater tendency of sickled red cell membranes to undergo lipid oxidation.