The erythrocytes of the metallic skink Niveoscineus metallicus

• 1.1. We studied the haemoglobin content, erythrocyte indices, erythrocyte enzymes and haemoglobin electrophoresis patterns of the metallic skink Niveoscineus metallicus and compared them to the small amount of published data on other small lizards.
• 2.2. Haemoglobin was much lower than that recorded for the salamander.
• 3.3. Erythrocyte enzymes (glucose phosphate isomerase and glucose 6 phosphate dehydrogenase) were lower in the skink than in the salamander. Glyceraldehyde phosphate dehydrogenase, phosphoglycerate kinase and pyruvate kinase were much higher in the skink than in the salamander.
• 4.4. A single, slow, haemoglobin component was identified by electrophoresis.

     

Freeze tolerance and intolerance as strategies of winter survival in terrestrially-hibernating amphibians

• 1.1. The ability to tolerate extracellular freezing as an adaptation for winter survival was tested in seven species of terrestrially-hibernating amphibians found in eastern Canada.
• 2.2. All species had only moderate supercooling abilities, with whole animal supercooling points of −1.5 to −3°C.
• 3.3. Two salamander species, Plethodon cinereus and Ambystoma laterale, and the toad, Bufo americamts, were freezing intolerant and were killed when frozen for 24 hr at temperatures just below their supercooling points. The major winter strategy of these animals appears to be behavioural avoidance of subzero temperatures.
• 4.4. Four species of frogs Rana sylvatica, Hyla versicolor, Hyla crucifer and Pseudacris triseriata, survived extracellular freezing at moderate subzero temperatures (−2 to −4°C) for periods of time ranging up to 2 weeks.
• 5.5. All four frog species accumulated low molecular weight carbohydrates as cryoprotectants, glycerol being the major cryoprotectant in adult H. versicolor, while immature adults of this species as well as the other three species all produced high levels of glucose as the cryoprotectant.

     

Diurnal temperature sensitivity of dairy cattle in a naturally cycling environment

• 1.1.|Vaginal temperatures of 15 Bos taurus cattle were monitored for 17 days in daily pens exposed to normal environmental fluctuations.
• 2.2.|Regressions of vaginal temperature on ambient temperature were made for each collection time in the 24 h cycle. Slopes of regressions provided an index of animal sensitivity to environmental temperature.
• 3.3.|Fluctuations in sensitivity occurred throughout the day with positive slopes excepts at 0630 h.

     

Acetylcholinesterase in Apis mellifera head during post-embryonic development. Existence of a glycoinositol-anchored membrane form at eary pupal stages

• 1.1. Properties of acetylcholinesterase (AChE, EC 3.1.1.7) from Apis mellifera head were studied during pupal development and at the adult stage.
• 2.2. During post-embryonic development, tissue and specific activities were closely related and increased to reach a maximum value at emergence and at last pupal stage, respectively.
• 3.3. In adults, AChE activity was weaker in foragers than in emerging bees.
• 4.4. The membrane form occurred in adult bees as well as in pupae whereas the soluble enzyme only appeared from Pd pupal stage.
• 5.5. The proportion of soluble and membrane forms fluctuated during late development but, in all cases, the percentage of the soluble form remained less than 10% of total AChE activity.
• 6.6. At all post-embryonic stages, the membrane form was sensitive to the action of phosphatidylinositol-specific phospholipase C (PI-PLC) and was converted into a hydrophilic enzyme.
• 7.7. In adult bees, the sensitivity to PI-PLC depended on the season. In summer, about 60% of the membrane activity could be solubilized by PI-PLC vs only 5% in winter.
• 8.8. The sensitivity of AChE to pirimicarb varied with the developmental stage.
• 9.9. In foraging bees, AChE was more susceptible to pirimicarb than in emerging bees. This difference of sensitivity to carbamate was abolished after removal of the membrane anchor either by mild trypsin digestion of PI-PLC treatment.

     

Evaporative water loss and uptake in juvenile and adult Salamandra salamandra (L.) (Amphibia: Urodela)

• 1.1. Both juveniles and adults of this rare salamander were studied.
• 2.2. The rate of evaporative water loss increased with temperature and at lower humidities.
• 3.3. At all four temperatures and three humidities studied, adults lost water at a lower rate than juveniles.
• 4.4. Aggregating juveniles reduced water loss especially at lower moisture.
• 5.5. The rate of water uptake was greater in juveniles than in adults.
• 6.6. Juveniles were capable of absorbing moisture from moist soil even at 40% saturated soil.

     

Expression of a P0-like glycoprotein in central nervous system myelin of amphibians (Ambystoma mexicanus,xenopus laevis and Rana catesbeiana)

• 1.1. The myelin protein profiles in the CNS and PNS of three species of amphibians were analyzed by biochemical and immunohistochemical methods.
• 2.2. The CNS myelin of the African clawed frog (Xenopus) and the Mexican salamander (axolotl) contained, in addition to proteolipid protein, a unique protein zero (P0)-like protein, whereas the adult bullfrog did not.
• 3.3. A strong expression of the P0-like protein in the bullfrog CNS myelin was found transiently at ontogenetically early phases including at the time of metamorphosis.
• 4.4. The CNS P0-like protein and the PNS P0 protein showed a difference in reactivity with lectins and anti-L2/HNK-1 antibodies, suggesting that the two proteins differ in some aspects of their carbohydrate structures.

     

Organ specific changes in energy metabolism due to anaerobiosis in the sea mussel Mytilus edulis (L.)

• 1.1. Anaerobic energy metabolism was investigated in different organs of Mytilus edulis and the whole animal.
• 2.2. Succinate accumulates to high levels in most organs but remains low in the hemolymph.
• 3.3. After 16 hours propionate accumulation is observed in all organs. Experimental evidence is not sufficient yet to point out organs that produce more propionate than others.
• 4.4. Acetate is a minor end product.
• 5.5. Acetate and propionate are found in the hemolymph in amounts equal to those in the organs.
• 6.6. Animals incubated in oxygen-free seawater accumulate more end products than animals exposed to air, in the form of volatile fatty acids that are excreted into the incubation water.
• 7.7. Alanine and glutamine increase in the posterior adductor muscle. Aspartate decreases in the total animal, posterior adductor muscle and gills, while in the hemolymph decrease in alanine, asparagine, serine, threonine and proline are observed.

     

Light-induced effects of several enzymes of carbohydrate metabolism in Phycomyces blakesleeanus

• 1.1. The photoregulation shown by glyceraldehyde 3-phosphate dehydrogenase and glucose 6-phosphate dehydrogenase appears to be independent of the mad gene product(s) and also independent of carotene biosynthesis regulation.
• 2.2. The photoregulation of malate dehydrogenase appeared to be dependent on the mutation of the mad and car S genes.
• 3.3. Pyruvate kinase and lactate dehydrogenase may be classified as light-independent.
• 4.4. The action of ATP and fructose 1,6-bisphosphate on the enzymes studied was generally independent of light/dark grown conditions.
• 5.5. However, the effect of fructose 1,6-bisphosphate on Phycomyces pyruvate kinase appears to be light-dependent.

     

Main kinetic characteristics of acetylcholinesterase from brain of Hypostomus punctatus,a Brazilian bentonic fish (cascudo)

• 1.1. A potentiometric method for the assay of cholinesterase has been proposed and compared with a colorimetric assay.
• 2.2. Main kinetic parameters of cholinesterase from Hypostomus punctatus brain were determined indicating that true acetylcholinesterase is by far the predominant enzyme in the brain of this fish.
• 3.3. We have compared our data with published results described from other fish species.
• 4.4. The enzyme inhibition achieved after 3 hr incubation of brain homogenates with ethyl-parathion have indicated that this enzyme shows a characteristic organophosphorous sensitive behavior.

     

Studies on tryptophan pyrrolase of Schistocerca gregaria försk. (Orthoptera)

• 1.The trytophan pyrrolase activity of central fat bodies of S. gregoria hoppera was studied.
• 2.The enzyme system appears to be similar to that of mammalian liver.
• 3.The enzyme was localized only in central fat bodies.
• 4.Extracts of other body parts can mimic an enzyme activity because of a degradation of ommochromes in the enzyme test.

     

Variations in the levels of progesterone in Mytilus edulis during the annual reproductive cycle

• 1.1. Progesterone levels in Mytilus edulis males and females during the annual reproductive cycle were analysed in the whole animal and in the gonads using gas-liquid chromatography and radioimmunoassays.
• 2.2. The high hormone levels in the whole animal were observed in July and October, coincident with the main spawning seasons.
• 3.3. The levels of progesterone in gonad extracts also show a maximum in summer (July).
• 4.4. The patterns of the progesterone levels in males and females throughout the annual reproductive cycle are similar.
• 5.5. These data are discussed in relation to the role of progesterone in the regulation of sex-specific processes, particularly gametogenesis.

     

A model for the dynamic properties of integrating fibers: Target localization in a three-dimensional space—II. Computer simulation

• 1.1. The stimulation sequence provoked by a luminous point moving in front of a column of ommatidia was simulated for the eye of Squilla mantis.
• 2.2. The output from the ommatidia is transferred to one tangential, integrating fiber as graded potentials. These potentials follow a gaussian-shaped angular sensitivity function for each ommatidium.
• 3.3. The tangential fiber sums the inputs as they arrive and generates a spike if the sum is above threshold at one instant of time and at one point of the fiber.
• 4.4. The histograms of instantaneous frequencies of spike discharge resemble the input-pattern histograms.
• 5.5. The discharge pattern changes with distance and speed of the moving spot as well for the simulations as in electrophysiological recordings, and is adapted to the size of the animal.
• 6.6. The shape of the histograms (i.e. the pattern of spike discharge) is assumed to transmit the information on the position, speed and size of a moving target.

     

Evidence for target site insensitivity to cyanide in Spodoptera eridania larvae

• 1.1. Isolated mitochondria from the whole southern armyworm larvae, Spodoptera eridania, show all of the characteristics of mammalian liver mitochondria, except for target site sensitivity to cyanide.
• 2.2. The armyworm larval mitochondria are 17 times less sensitive to cyanide when compared to rat liver mitochondria and cannot be completely inhibited with extremely large doses.
• 3.3. These data suggest the presence in the southern armyworm of either a cyanide-insensitive cytochrome oxidase, or the elaboration of cyanide-insensitive oxidative pathway reminiscent of an alternative oxidative pathway that is known to coexist in plants alongside the cyanide-sensitive pathway.

     

Liver glycogen mobilization by Trypanosoma brucei sonicates

• 1.1. The African trypanosome, T. brucei, appears to possess a hormone-like substance capable of stimulating the production of glucose from glycogen.
• 2.2. The effect of this substance is primarily on the liver as demonstrated in vitro.
• 3.3. The effect is consistent and independent of host conditions provoking an immune response.
• 4.4. The data are discussed with respect to the endocrinological aspects of the host and its corresponding involvement.

     

Is the lipolytic response in porcine adipose tissue slices equivalent to the lipolytic response in isolated adipocytes?

• 1.1. In most cases, when isolated adipocytes and adipose tissue slices from the same animal were stimulated with various lipolytic agents (adrenergie agonists, theophylline, adenosine deaminase), the qualitative response was similar.
• 2.2. There were, however, numerous exceptions; e.g. quinterenol did not affect isolated adipocytes whereas it was a partial agonist for adipose slices from the same animal.
• 3.3. The adipocytes present in slices were larger than those isolated from slices by collagenase digestion.
• 4.4. Isolated adipocytes were not more sensitive than tissue slices to stimulation by lipolytic agents.

     

The carotenoids of eggs of wild and farmed cod (Gadus morhua)

• 1.1. Eggs of wild cod, and of farmed cod fed (a) a diet supplemented with astaxanthin and (b) a diet supplemented with both astaxanthin and canthaxanthin, were analysed with respect to carotenoids.
• 2.2. The total carotenoid contents in eggs were 0.7 ppm for wild cod and 0.5 ppm for farmed cod.
• 3.3. Cod, having white flesh, deposit ketocarotenoids in the eggs, preferably astaxanthin.
• 4.4. Canthaxanthin can replace astaxanthin in the eggs, but astaxanthin appears to be deposited preferentially when both carotenoids are present in the diet.
• 5.5. The isomer distribution of (3S, 3′S):(3R, 3′S, meso):(3R, 3′R) astaxanthin in the eggs reflected the isomer composition of the diet.
• 6.6. Echinenone, 4′-hydroxyechinenone, adonixanthin and zeaxanthin encountered in cod eggs may represent reductive metabolites of canthaxanthin and astaxanthin.

     

Bioelectric activity from isolated brain of Lacerta atlantica

• 1.1. A method of maintaining the isolated lizard brain in a Ringer solution is described.
• 2.2. Microelectrodes and EEG recordings from different areas of telecenphalon and optical tectum were made.
• 3.3. The prolonged cells survival under the experimental conditions described has been demonstrated for several hours.
• 4.4. The isolated brain of Lacerta makes it easy to reach anatomical pathways which otherwise, in the whole animal, would be more difficult to reach.

     

Characterization of two distinct latent proteinases associated with myofibrils of crucian carp (Carassius auratus cuvieri)

:

• 1.1. Enzymatic properties of two distinct proteinases tightly associated with crucian carp myofibrils were characterized.
• 2.2. These proteinases were latent but activated at 50 and 60°C, respectively.
• 3.3. The optimum pH of 50°C-proteinase was neutral-alkaline, while that of 60°C-proteinase was weak acid-neutral pH.
• 4.4. Both proteinases required more than 1% NaCl for the activity, but 50°C-proteinase was partially inhibited at higher concentrations of NaCl.
• 5.5. Both proteinases were regarded as trypsin-like proteinases belonging to a serine proteinase family, but only 60°C-proteinase was sensitive to urea, n-butanol and iso-propanol.

     

The distribution of monosaccharides and hexosamines in the oviduct of Salamandra salamandra (L.) (Amphibia,Urodela)

• 1.1. Biochemical analysis of the different segments of the oviduct in the ovoviviparous salamander, Salamandra salamandra, reveals the monosaccharides glucose, galactose, fucose, mannose, ribose and the hexosamines glucosamine and mannosamine.
• 2.2. In segment 1 (pars recta) ribose and mannose are absent, and in segments 2 (p. convoluta I) and 5 (p. convoluta IV, uterus) mannose is not detectable; fucose is absent in the uterus. Segments 3 (p. convoluta II) and 4 (p. convoluta II) contain all sugars identified.
• 3.3. The main hexoses present in the glandular segments are galactose, fucose and glucose.

     

2-Deoxyglucose transport by the frog sartorius: Effects of electrical stimulation and N-carbobenzoxy-glycyl-l-phenylalaninamide

• 1.1. Studies characterizing glucose transport in the frog sartorius were performed.
• 2.2. For nonstimulated and stimulated muscles, intracellular 2-deoxyglucose exceeded 2-deoxyglucose-6-phosphate at 15 min, showed little further increase, and was maintained below the extracellular concentration for 2 hr.
• 3.3. Accumulated 2-deoxyglucose-6-phosphate did not inhibit glucose transport.
• 4.4. Unlike in adipocytes, basal and stimulated 2-deoxyglucose transport showed no difference in sensitivity to N-carbobenzoxy-glycyl-l-phenylalaninamide.
• 5.5. Phenylarsine oxide blocked contraction-enhanced 2-deoxyglucose uptake.
• 6.6. These results suggest that the glucose transporter of the sartorius exhibits auto-regulation, and that basal transport is not regulated by the same process as in adipocytes.