Respiration in the eastern water dragon,Physignathus lesueurii (agamidae)

• 1.1. Some aspects of the gas exchange system of a diving lizard, Physignathus lesuewii were studied.
• 2.2. Breathing patterns were analysed.
• 3.3. Breathing rate increases logarithmically with temperature and Q₁₀ = 1.8. LogBR = −0.237 + 0.0256 T.
• 4.4. Gas tensions in lung air and arterial and venous blood were measured. Arterial pH declines with increasing temperature.
• 5.5. Temperature has a marked effect on oxygen affinity of the blood (ΔH = −10.1 kcal mol⁻). A Bohr effect was also noted.
• 6.6. CO₂ equilibrium curves were drawn.
• 7.7. The results are considered with a view to anticipating the efficiency of the gas exchange system of this species under conditions of variable temperature and during diving.

     

O2-binding by the blood of the landhopper,Arcitalitrus dorrieni (Hunt) (Crustacea: Amphipoda)

• 1.1. The O₂-binding characteristics of the blood of the euterrestrial amphipod (landhopper) Arcitalitrus dorrieni have been studied.
• 2.2. The blood exhibited a low O₂ affinity, with a p₅₀ (at pH = 7.8) of 21.4 torr (10°C). Affinity decreased with an increase in temperature at constant pH (ΔH = − 79.4kJ/mol) but the Bohr factor (ΔlogP₅₀/Δ pH = −0.67) was unaffected.
• 3.3. The O₂-carrying capacity of the blood was moderate (1.51 ml/100 ml)
• 4.4. The results support the hypothesis that the blood of terrestrial amphipods is characterized by having a low affinity pigment.

     

The dependence of oxygen consumption of the common whelk (Buccinum undatum) on hypoxia,salinity and air exposure

• 1.1. Oxygen consumption of low salinity (20‰) acclimated whelks decreases markedly upon acute exposure to hypoxia (P_WO₂ = 35 Torr), but almost regenerates its original level within 48 hr exposure to the hypoxic condition.
• 2.2. This ability to regain the original level of oxygen consumption is not seen in high salinity (35‰) acclimated whelks.
• 3.3. Oxygen consumption in air at 10°C is more than twice the rate shown by low salinity acclimated whelks in normoxic water (P_WO₂ = 150 Torr).
• 4.4. Q₁₀ for oxygen consumption in air is about 1.0 in the temperature range 10–20°C.

     

Effects of exercise-stress on ventilation,cardiac output and blood respiratory parameters in the carp,Cyprinus carpio

• 1.1. Carp (Cyprinus carpio) were stressed to exercise by rolling in a respiration chamber. Ventilatory water flow rate, cardiac output and blood respiratory parameters were determined.
• 2.2. During exercise, oxygen uptake increased about 3.5-fold and returned to pre-exercise level within 15 min.
• 3.3. This exercise-stress resulted in no plasma acidosis and in no swelling of the erythrocytes.
• 4.4. Ventilatory water flow rate increased 6-fold, whereas cardiac output increased 2-fold. Hence the ventilation-perfusion ratio increased during exercise.
• 5.5. During exercise, arterial O₂ content (CaO₂) increased due to increases in O₂ tension (PaO₂), O₂ saturation of hemoglobin (SaO₂) and hemoglobin concentration (Hb). On the other hand, Pv̄O₂ and Sv̄O₂ remained at the resting levels but Cv̄O₂ slightly increased due to an increase in Hb.
• 6.6. Arterial-venous O₂ difference (CaO₂-Cv̄O₂) increased by 38%, which was met by a much greater increase in CaO₂ than Cv̄O₂.

     

Purification and characterization of hatching enzyme of the pike (Esox lucius)

• 1.1. A choriolytic enzyme was isolated from the hatching medium of the pike, Esox lucius.
• 2.2. The enzyme is defined as hatching enzyme.
• 3.3. The molecular weight of the enzyme is 24,000.
• 4.4. The enzyme is a glycoprotein containing 2% carbohydrate.
• 5.5. Its isoelectric point is 6.5.
• 6.6. The pH optimum is around pH 8.
• 7.7. The enzyme molecule contains two disulfide bonds but no free cysteine.
• 8.8. Inhibitor studies and metal analysis show that the enzyme is a zinc-metalloprotease.

     

The flow theory of enzyme kinetics: Role of solid geometry in the control of reaction velocity in live animals

• 1.1. When blood flows, membranes are bombarded with ions etc., whose entry creates an ATP demand proportional to flow rate. Also proportional to flow rate is ATP production from oxidation of substrates [S] from the same blood volume.
• 2.2. O₂ is limiting and reaction velocity at rest (metabolic rate) is determined by flow rate, F, but not by [S].
• 3.3. Since resting blood O₂ A-V difference is about 5 vol%, 11 circulated produces about 0.25 kcal in mammals, birds or warm reptiles.
• 4.4. Where O₂ is not limiting, as in most amino acid deaminations, V = K F[S] with K a constant unrelated to K_m.
• 5.5. At equal blood vol/kg, solid geometry dictates that the average cross-sectional area of major vessels/kg will be an inverse function of body mass. The smaller the animal, the shorter the vessels, the “thicker” the vessels/kg body wt, and at any one blood pressure, the higher the flow/kg/hr. If a man's major vessels were equal in cross-section/kg to those of a shrew, it would take 2241 of blood to fill them.
• 6.6. Growth decreases flow/kg (and therefore metabolic rate), by decreasing vessel cross-section/kg without changing blood pressure or linear velocity of flow.
• 7.7. Surface area/g, body wt to some power, average vessel length/kg, circulation time and average major vessel cross-sectional area are all related mathematically.

     

Aerial respiration in the semaphore crab,Heloecius cordiformis,with or without branchial water

• 1.1. Semaphore crabs (Heloecius cordiformis) are active in air at low tide. Their branchial chambers are lined with a vascular epithelium and are expanded above the gills (five pairs) to form air cavities which could function as lungs. Water is continuously circulated over the gills.
• 2.2. The relative contribution made by the gills and lungs to gas exchange in semaphore crabs active in air and circulating branchial water, was determined by measuring oxygen consumption (at 25°C) in crabs with and without branchial water, and in crabs with their lungs subsequently occluded.
• 3.3. Activity levels and VO₂ were unaffected by the absence of branchial water.
• 4.4. With their lungs occluded, VO₂ dropped (on average) by 61% in crabs with branchial water (i.e. gills still functional) and by 81% in crabs without branchial water (gill function impaired).
• 5.5. It is concluded that semaphore crabs are obligate air breathers while active on land, despite carrying water within their branchial chambers. Lung development and gill reduction in land crabs is discussed briefly in relation to “terrestriality”.

     

Ventilatory rate in the butterfish (Pholis gunnellus) as a consequence of temperature and previous emersion

• 1.1. Observation of ventilation in immersed Pholis gunnellus showed a linear relationship between ventilatory rate and temperature between 8 and 20°C.
• 2.2. At 13°C and after 30 min emersion, ventilatory rate was initially lower than prior to emersion, providing evidence of adequate uptake of O₂ for standard metabolism during the emersion period.
• 3.3. This species has a laterally elongate body form with reduced scales and extensive mucus secretion.
• 4.4. During emersion, gaping behaviour probably exposes the gills and extensively vascularised oesophageal regions to air.
• 5.5. These are considered to be morphological and behavioural adaptations by P. gunnellus, to aerial respiration in the intertidal habitats occupied by this species.

     

The influence of aerial exposure on gas exchange and cardiac activity in the shore crab,Carcinus maenas (L.)

• 1.1. The cardiovascular physiology of adult Carcinus maenas (L.) emerging into air has been investigated at three different air temperatures.
• 2.2. Transition from seawater to air or vice versa triggered transient increases in cardiac and locomotor activity.
• 3.3. However, crabs became inactive 5–10 min after emerging from seawater (15°C) into air at the same temperature (15°C) or at lower temperatures (12–13°C) and heart rate fell.
• 4.4. At higher air temperatures (18–20°C) heart rate rose but to a lesser extent than predicted from aquatic Q₁₀ heart-rate values.
• 5.5. Crabs were again quiescent in aerial conditions.
• 6.6. Mean arterial oxygen tension (Pa_o2) was ~ 74 mmHg in submerged crabs but fell to ~ 38 mmHg in air while mean arterial carbon dioxide tension (Pa_o2) increased from 1 to 4 mmHg resulting in respiratory acidosis.
• 7.7. A model of gill function is proposed to explain the development of internal hypoxia in air.
• 8.8. The results are discussed in relation to the distribution of adult and juvenile C. maenas in situ.

     

Blood changes in japanese eels,Anguilla japonica,experimentally infected with typical or atypicalAeromonas salmonicida

• 1.1. Changes in the blood and in the rate of oxygen consumption of Japanese eels injected intramuscularly in the head with a lethal dose of typical or atypical Aeromonas salmonicida at 20°C were investigated.
• 2.2. Eels infected with the bacteria became moribund within 4 to 6 days, and then died within 1 day.
• 3.3. The O₂ consumption rate and blood parameters changed markedly with infections. The responses of hosts to infection by the two kinds of bacteria differed with regard to the following four points: blood pH, plasma Cl⁻, lactic acid, and the numbers of granulocytes and lymphocytes.
• 4.4. The responses of eels infected with atypical A. salmonicida were larger and more rapid than those of eels infected with typical A. salmonicida.

     

Cellular and intracellular localization of catalase and acid phosphatase in the midgut of Lumbricus terrestris L.: A cell fractionation study

• 1.1. Cellular and intracellular localization of catalase and acid phosphomonoesterase in the midgut of Lumbricus terrestris was studied by use of tissue fractionation.
• 2.2. At least 60–70% of the catalase resides in the chloragocyte cytosol and the remaining 30–40% resides in gut epithelium peroxisomes.
• 3.3. One of the main functions of the chloragocyte catalase is probably scavenging for H₂O₂ arising from the interaction between blood heme-protein and oxygen.
• 4.4. A simple method for the histochemical detection of cytosol catalase is proposed.
• 5.5. About 10% of the gut acid phosphatase resides in chloragocyte lysosomes. The chloragosomes contain no acid phosphatase.

     

Purification and some properties of an atypical alkaline p-nitrophenylphosphate phosphatase activity from Halobacterium halobium

• 1.1. An alkaline p-nitrophenylphosphate phosphatase has been purified 440-fold from extracts of Hatobacterium halobium.
• 2.2. The enzyme has an apparent molecular weight of 24,000.
• 3.3. A K_m value for p-nitrophenylphosphate of 1.12mM has been found under optimal conditions.
• 4.4. The enzyme is selectively activated and stabilized by Mn²⁺.
• 5.5. It requires high salt concentrations for stability and maximum activity.
• 6.6. It displays an unusual restricted substrate specificity of 25 phosphate esters tested, only phosphotyrosine and casein were hydrolysed besides p-nitrophenylphosphate.

     

Factors affecting oxygen consumption in wild-caught yellow-bellied marmots (Marmota flaviventris)

• 1.1. All age groups gained mass during the active season, but mass-gain of adult females was delayed during lactation.
• 2.2. The relationship of body mass to metabolic rate varied widely; when the relationship was significant, R² varied from 10.3 to 72.6%. Body mass affects V_O2 more during lactation than at any other period.
• 3.3. Mean VinO₂ of adult males was higher in June than that of adult, non-lactating females.
• 4.4. V_O2 of reproductive females was significantly higher during lactation than during gestation or postlactation because specific V_O2 varied. Specific V_O2 of non-reproductive females declined over the active season.
• 5.5. Specific V_O2 of all age groups declined between the premolt and postmolt periods. The reduced maintenance costs can contribute 20–46% to daily growth.
• 6.6. Observed V_O2 was lower than the value predicted from intraspecific or interspecific Bm:M regressions.
• 7.7. V_O2 of wild-caught marmots was lower than that of marmots maintained in the laboratory, probably because of dietary differences.
• 8.8. Because basal metabolism is a stage on a food-deprivation curve, we suggest that basal metabolic rate is not an appropriate measure of the metabolic activity of free-ranging animals.

     

Respiratory gas concentrations in the microhabitats of some florida arthropods

• 1.1. The concentrations (dry gas %) of oxygen and carbon dioxide were measured in a variety of microhabitats of arthropods in Florida: at the ends of the burrows of three spider species (Sphodros abboti, Geolycosa micanopy, Cyclocosmia torreya) and a tiger beetle (Megacephala carolina) larva, within ant (Solenopsis invicta) mounds, within stumps inhabited by termites (Reticulitermes flavipes), and within and under decaying hardwood logs.
• 2.2. Hypoxia and hypercarbia occurred in all microhabitats, with the ratio of oxygen decrement to carbon dioxide increment close to one. Changes for both gases were minor in the spider burrows, under decaying logs, and within ant mounds (<2.3% for O₂ and 1.1% for CO₂) and are probably physiologically unimportant to their inhabitants.
• 3.3. In contrast, %O₂ fell to as low as 12–14%, and CO₂ rose to as high as 6–8%, in the burrows of tiger beetle larvae, within decaying logs, and inside decaying stumps inhabited by termites.
• 4.4. Such changes, particularly for CO₂ may present a challenge to organisms living in these microenvironments.
• 5.5. Approximately 20–25% of the changes in the concentrations of respiratory gases in the burrows of tiger beetle larvae are attributable to the metabolism of the larva, the remainder being due to diffusional exchanges with the soil.

     

Oxygen uptake in larval bollworms (Heliothis zea) infected with the fungus Nomuraea rileyi

• 1.1. Healthy 6- to 12-day-old Heliothis zea (bollworm) larvae showed a mean oxygen uptake of 3.1 μl O₂/mg body wt per hr.
• 2.2. Similar larvae infected with the fungus Nomuraea rileyi had a mean uptake of 4.01 μl O₂/mg per hr.
• 3.3. The weights of the two groups of insects did not differ.
• 4.4. T-test showed a significant (P < 0.01) difference in oxygen uptake between healthy and infected larvae.

     

A comparative study of the respiratory properties and physiological function of haemocyanin in two burrowing and two non-burrowing crustaceans

• 1.1. Oxygen dissociation curves were constructed for the haemolymph of two non-burrowing, Galathea strigosa and Eupagurus bernhardus, and two burrowing crustaceans, C. cassivelaunus and Nephrops norvegicus. The p₅₀ at in vivo pH values and 10°C was 12.6 Torr in G. strigosa, 23 Torr in E. bernhardus, 3.1 Torr in C. cassivelaunus and 11.5 Torr in N. norvegicus.
• 2.2. The Bohr values (Δlogp₅₀/ΔpH) were high in all species ranging between −0.96 and −1.48. Cooperativity expressed as P₅₀ averaged 3.3, 3.8 and 3.8 in G. strigosa, E. bernhardus and N. norvegicus. respectively. A lower value of 2.2 was observed in C. cassivelaunus.
• 3.3. The oxygen affinity of the haemocyanin was relatively temperature independent, the values for ΔH at pH7.9 ranging between −5.1 and −18.1 kJmol⁻¹.
• 4.4. Haemolymph respiratory gas analysis showed values similar to those previously reported in crustaceans: p_aO₂ ranging between 44 and 107 Torr and p_vO₂ values between 18 and 24 Torr.
• 5.5. Pre-/post-branchial pH differences were small in G. strigosa, E. bernhardus and N. Norvegicus, but averaged 0.09 of a pH unit in C. cassivelaunus. p_aCO₂ and P_vCO₂ values ranged between 1.4 and 2.3 Torr.
• 6.6. In buried C. cassivelaunus both pre- and post-branchial oxygen tensions decreased, as did oxygen tension overall during respiratory pauses.
• 7.7. Cardiac output values were low, ranging between 59 and 71 ml kg⁻¹ min⁻¹ for all four species and calculated stroke volumes were realistic in terms of animal size.
• 8.8. In the non-burrowing species physically dissolved oxygen accounted for 5–21% of the oxygen transported to the tissues. In the burrowing species values of 40–77% were found.

     

The effect of temperature on the acid-base status of the blood of the hatching quail (Coturnix c. japonica)

• 1.1. The ambient temperature of embryos of pipped eggs was reduced from 38 to 28°C for a period of 45 min.
• 2.2. The blood P_CO2 was lower and the blood more alkaline at 28°C than at 38°C.
• 3.3. At 28°C plasma [HCO₃⁻] ] was lower than predicted from the blood buffer line determined in vitro.
• 4.4. The plasma concentrations of strong ions and lactate were the same at both temperatures.
• 5.5. After the ambient temperature had been returned to 38°C for a period of 45 min, blood pH was more acidic than before cooling, but there was no difference in blood P_CO2.
• 6.6. The plasma [HCO₃⁻] was the same as that at 28°C and plasma [K⁺] was higher than before cooling.
• 7.7. The results arc discussed in relation to the factors affecting blood pH in embryos at this stage of development.

     

Comparative study of the oxyhaemoglobin dissociation curve of four mammals: Man,dog, horse and cattle

• 1.1. The entire oxygen dissociation curve (ODC) and the effects of temperature, pH and 2,3-diphosphoglycerate (DPG) on this curve, have been compared in four mammalians: man, dog, horse and cattle.
• 2.2. If the oxyphoric capacities are similar between these species (around 1.39ml O₂/gHb), their P50, measured in standard conditions, i.e. at pH 7.4;.pCO₂ 40mmHg and T 37°C, varies between 23.8 (± 0.8) mmHg for the horse, 25.0 (± 1.4) mmHg for cattle, 26.6 (± 1.2) for man and 28.8 (± 2.6) mmHg for the dog.
• 3.3. The higher dispersion of the dog's P50 is due to difference between breeds; in seven breeds investigated, the P50 ranges from 25.8 (spaniel) to 35.8 (hound).
• 4.4. We noted no sex difference in the four species.
• 5.5. The DPG level is confirmed to be low in cattle (< 1 μmol/gHb) as compared to man (13.5 ± 2.1 gmmol/gHb), horse (16.9 ± 1.1 gmmol/gHb) and dog (19.4 ± 2.8 μmol/gHb).
• 6.6. The oxygen exchange fraction defined as the difference in vol% between a pO₂ of 80 and 35 mmHg is, respectively, 3.6 (± 0.6) vol% for cattle, 4.0 (0.4) vol% for the horse, 5.5 (± 0.5) vol% for man and 6.6 (± 1.7) vol% for the dog.
• 7.7. The position and shape of the ODC, as well as T, DPG and pH effects, indicate that the haemoglobin of man and dog seem better adapted to O₂ delivery as compared to the horse and cattle.

     

A note on eggshell porosity,nest humidity and the effects of DDE in the grey heron (Ardea cinerea)

• 1.1. Water vapour conductance (G_H2O) was determined for 25 grey heron Ardea cinerea eggs in the laboratory, and in nests during natural incubation at two Scottish colonies.
• 2.2. The mean G_H2O of eggs measured in the nest which successfully hatched was 9.0 mgH;O/mmHg/day and the mean water vapour pressure gradient between egg and nest (ΔP_H2O), measured using “calibrated” duck eggs, averaged at 31 mmHg (4.13 kPa).
• 3.3. Based on eggshell porosity results, from the eggs which hatched, such a gradient would result in a loss of water from the eggs during incubation equivalent to 11% of their fresh weight.
• 4.4. Shell thickness, the number of pores/cm² of eggshell and DDE content were also determined for the 25 eggs measured in the laboratory.
• 5.5. Eggs containing high levels of DDE had thinner shells, more pores in the eggshell and a higher overall eggshell porosity.
• 6.6. The main problem posed by a high level of DDE would appear, however, not to be an excessive water loss from the egg during incubation, but rather eggshell thinning leading to a loss of the egg due to breakage in the nest.

     

The purification and properties of a ribonuclease of the roe of the fish Cyprinus carpio L.

• 1.1. An acid RNase was purified 620-fold from the roe of the fish Cyprinus carpio L. The recovery was 12.4% and the enzyme appeared to be homogenous as judged by the SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE).
• 2.2. The enzyme displays maximum activity at pH 5.50, I = 50 mM and the mol. wt is 22,000.
• 3.3. The purified enzyme shows two molecular forms (pI₁ = 4.04, pI₂ = 4.75) as revealed by the isoelectric focusing technique.
• 4.4. The enzyme hydrolyses both Poly(A) and Poly(U) showing a stronger preference for Poly(U), Neither Poly(G) nor Poly(C) was hydrolysed.