Comparative biochemistry and physiology最新文献

1. A number of key glycolytic and gluconeogenic enzymes were identified in the foot, mantle and gill tissue of the quahog, Mercenaria mercenaria.

2. Catalytic rates averaged about 4 per cent of the rates found in rat liver, but revealed a general similarity in proportional enzyme activity between molluscan and mammalian tissue.

3. Quahogs maintained under conditions of partial starvation showed changes in glycogen, glucose-6-phosphate dehydrogenase and fructose diphosphatase levels similar to those observed in mammalian tissue.

1. The oxidation of reduced pyridine nucleotides by microsomal preparations from the abdomen of the adult housefly, Musca domestica, has been examined and characterized.

2. NADPH oxidation is stimulated by exogenous cytochrome-c and inhibited by CO and sulfhydryl inhibitors.

3. The effect of metal ions, synergists and known substrates for microsomal mixed function oxidases is also examined.

4. Added xenobiotics substrates are not required for NADPH oxidation by these preparations.

1. Caseins from rat and mouse milk were purified following rennin-Ca²⁼ precipitation.

2. Acrylamide gel electrophoresis revealed four components in rat and five componenst in mouse casein. At least one component migrated similarly in both caseins.

3. Immunodiffusion and immunoelectrophoretic analysis indicated that anti-bodies to mouse casein exhibit incomplete cross-reactivity to similar casein components in mouse and rat milk. Antibodies to rat casein recognized four components in rat milk, an donly one component in mouse milk. The mouse milk component was identical to one of rat components.

4. Radioimmunoprecipitation analysis suggested that antibodies against rat and mouse casein recognize heterologous caseins, but precipitation in less efficient.

1. Parallel estimates of thirteen serum parameters were made in four female and eight male paddlefish taken at spawning.

2. Sexual “dimorphism” was found in serum non-protein nitrogen, cholestrol, and cortisol.

3. Although paddlefish appeared to regulate the major electrolyte, Na, K and Cl, similar to other freshwater teleost, both sexes had lower serum Ca, NPN, protein and glucose concetrations.

4. Low serum Ca levels in paddlefish suggest physiological hypocalcemia and, in this respect, paddlefish show phylogeneitc affinity to the other chondrostei, the sturgeons.

Blood proteins of the Plagiodontia hylaeum, Capromy's pilorides and Geocapromys ingrahami, all beloning to a rare primitive family of rodents, Capromyidae, were examined by strach gel electrophoresis.

2. Patterns characteristics of the species were found.

3. Comparisons were made the blood proteins of the most closely related living family Myocastoridae, Myocastor coypus (nutria)

4. Data on unique haptoglobin variants in the Capromys pilorides are presented. Three phenotypes are demonstrated.

1. Fifteen species of Sebastodes were separated into three groups on the basis of mobility of tetrazolium oxidase in starch gels.

2. An apparent relation was observed between tetrazolium oxidase mobility and spawning season.

1. The activities of malic dehydrogenase, malic oxidase, succinic dehydrogenase, succinic oxidase and cytochrome oxidase were measured in homogenates of whole adult male and female Drosophila melanogaster grown at 15 and at 25°C. The activities assayed at 15 and 25°C are reported and only with succinic dehydrogenase was evidence of temperature adaptation noted.

2. The activities of malic oxidase, malic dehydrogenase, succinic dehydrogenase and cytochrome oxidase were assayed in D. pseudoobscura grown at 15 and at 25°C. There was no evidence of temperature adaptation in the activities measured at 15 and at 25°C.

3. Malic dehydrogenase and cytochrome oxidase were assayed in D. willistoni grown at 15 and at 25°C. The flies grown at the lower temperature have higher enzyme activity than those grown at 25°C. This is interpreted as a capacity adaptation.

4. It is suggested that temperature adaptation would not be expected with some of these enzymes because their Q₁₀ values are low. In general, the results reported here do not add support to the theory that eurythermal species such as D. melanogaster have a greater capacity for temperature adaptation than do stenothermal species such as D. pseudoobscura and D. willistoni.

1. Dietary fatty acid fraction of larval faeces of Trogoderma granarium, containing palmitic, stearic, oleic and linoleic acids, induces and maintains the diapause in the larvae of the same species; linoleic acid is highly efficient either by feeding or by injection.

2. A comparative examination of the fatty acid composition of diapause and nondiapause larvae of T. granarium showed that the diapause insects have an increased concentration of the bound myristoleic, palmitoleic and linoleic acids accompanied by a decrease in palmitic acid content.

3. Mass spectra, infra-red and R_f values for fatty acid esters of larval faeces are given.