The effects of cooling the egg on the respiratory movements of the hatching fowl,Gallus g. domesticus,with a note on vocalization

• 1.1. The ambient temperature of pipped eggs of the domestic fowl was reduced from 39 to 20°C for a period of 2 hr.
• 2.2. In the majority of embryos the amplitude of respiration more than doubled during the first hour, and in each embryo the frequency fell to a minimum value by the end of cooling.
• 3.3. When the eggs were rewarmed the respiratory frequency usually returned to normal within a period of 1 hr. Vocal activity was often stimulated and was accompanied by a marked increase in the amplitude of respiration.
• 4.4. These results are discussed in relation to the development of thermoregulation, and are compared with results obtained elsewhere in a similar study on the quail.

     

Effects of photoperiod on sodium flux in Corbicula fluminea (Mollusca:Bivalvia)

• 1.1. A significant diurnal rhythm of net sodium flux was demonstrated in the freshwater clam Corbicula fluminea entrained to either a 12L:12D or 24L photoperiod.
• 2.2. Highest net flux occurred during the dark hours on 12L: 12D. The overall mean net flux over 24 hr was not significantly different from a steady state condition.
• 3.3. Net flux values of clams on a 24L photoperiod were negative and significantly lower than the net flux on a 12L:12D photoperiod.
• 4.4. The 12L: 12D net sodium flux rhythm pattern is similar to rhythmic patterns of other physiological processes in another freshwater clam.

     

Correlation of water translocation,cuticle dehydration and post-ecdysial sclerotization by the american cockroach

• 1.1. Haemolymph volume decreases during the initial 16 hr post-ecdysial period, increases after water ingestion and subsequently drops until the inter-ecdysial level is reached.
• 2.2. Total body water follows a similar pattern, but the changes are not as pronounced.
• 3.3. Tissue water is inversely proportional to the total body water.
• 4.4. Soluble cuticle protein declines throughout the initial 16 hr period while both β-glucosidase and alkaline phosphatase activity is lost within 6 hr after ecdysis.
• 5.5. Dehydration of the cuticle also occurs during the immediate 6 hr post-ecdysial period.
• 6.6. These data suggest that the formation of the protein-insoluble matrix is linked with water loss.
• 7.7. Water removal may decrease the distance between molecules allowing specific reactions to take place.

     

Laboratory studies on the oxygen consumption of the marine teleost,Lichia amia (Linnaeus, 1758)

• 1.1. The oxygen consumption of the marine teleost, Lichia amia was investigated under controlled laboratory conditions.
• 2.2. The routine oxygen consumption showed a strong circadian rhythm with the fish being mainly active during the light period.
• 3.3. The specific mass exponent (dimension: μg O₂/g/hr) is temperature independent and ranges from 0.27–0.29.
• 4.4. Starving the fish results in a mean decrease in active, routine and standard oxygen consumption of 21%, 24% and 20%, respectively.
• 5.5. Feecling led to an increase in the oxygen consumption of the teleosts, with the mean metabolic rate over the 24 hr that followed, being 58% and 50% higher for fish that had been starved for 162hr and 40 hr, respectively.
• 6.6. Apparent SDA showed some variation and ranged from 6.0 to 35.5%.
• 7.7. The results obtained are generally in agreement with those recorded for other teleosts.

     

Heterogeneity of amino acid transport activity in the avian small intestine

• 1.1. The absorption of leucine into the small intestine of the domestic fowl was studied by a tissue-accumulation procedure.
• 2.2. Leucine transport rates were found to cluster about discrete values when many individual chickens from a variety of strains were surveyed.
• 3.3. The basis for such differences in transport activity is discussed.

     

Light-induced transient increase of the activity of topoisomerase I in plasmodia of Physarum polycephalum

• 1.1. Activity of topoisomerase I and incorporation of [³H]uridine and [¹⁴C]thymidine were monitored during light-induced sporulation of the slime mold Physarum polycephalun.
• 2.2. A 4-fold transient increase of topoisomerase I activity but not of [³H]uridine or [¹⁴C]thymidine incorporation was observed after 42 hr of illumination with 6 hr impulses.
• 3.3. The activity of topoisomerase I did not increase in the absence of light impulses. However, ca 5-fold increase of the activity was observed in dark when 100 μ M dibutyryl-cAMP was administered 12 hr before harvesting of plasmodia.
• 4.4. Fluorodeoxyuridine and cycloheximide administered 36 hr after starting of the illumination cancelled the increase of the activity of topoisomerase I.
• 5.5. After 7 days of the illumination, when fruiting bodies appeared, the activity of topoisomerase I dropped to about 15% of the initial value.

     

The effect of time on physiological changes in eel Anguilla anguilla,induced by lindane

• 1.1. Eel were exposed to a sublethal concentration of lindane (0.335 ppm) for 6, 12, 24, 48, 72 and 96 hr.
• 2.2. Concentrations of glycogen, glucose, lactate, pyruvate and lipids were determined in gill tissue after lindane exposure.
• 3.3. Gill glycogen descreased and glucose levels increased at 6 hr of treatment, lactate and pyruvate concentration increased between 6 and 48 hr. Total lipid values decreased between 6 and 24 hr; thereafter, the levels increased up to 72 hr of exposure.
• 4.4. Clear changes were found in all parameters tested in gill tissues. The observed effects of lindane on metabolism in fish are discussed in relation to acute stress syndrome.

     

Circadian rhythms of determined blood chemistry values in buzzards and eagle owls

• 1.1. Fifteen values were determined in blood samples from six buzzards (Buteo buteo) and six eagle owls (Bubo bubo) over the 24 hr of the day.
• 2.2. Glucose, urea, uric acid, triglyceride and calcium values showed diurnal rhythms in both species. Their respective patterns of diurnal variation were compared.
• 3.3. Phosphorus, cholesterol and cholinesterase levels underwent circadian rhythms only in the buzzards. Albumin/globulin and amylase exhibited diurnal variations exclusively in the eagle owls.
• 4.4. Glutamatic oxaloacetic transaminase, albumin, globulin, total protein and creatinine concentrations did not show diurnal rhythms in either of the species.
• 5.5. Blood values of the different parameters were studied on the basis of the ranges described in birds.

     

Heart rate and blood pressure in bullfrogs during prolonged maintenance in water at low temperature

• 1.1. Bullfrogs were maintained in air-saturated water at 4°C under an 8:16hr, light:dark, photoperiod for 50 days from December to February.
• 2.2. Heart rates and mean arterial pressures from these submerged frogs remained stable throughout the entire period in the cold. The slow heart rates that were observed appeared to result from a combination of low temperature and submergence. No indication of torpor was observed in any of the animals.
• 3.3. These findings demonstrate that the cardiovascular system of bullfrogs apparently retains normal regulatory function when these animals are maintained under temperature and photoperiod conditions analogous to those found during overwintering.

     

Respiratory and blood gas responses in exercising birds

• 1.1. The effects of exercise in birds on changes in body temperature, ventilation, blood gases and air-sac gases are reviewed.
• 2.2. Except in the case of isothermic exercise below the anaerobic threshold, birds hyperventilate during exercise. Exercise hyperventilation is greater at higher exercise intensities and at higher environmental temperatures.
• 3.3. The domestic fowl appears to be a suitable model for the study of physiological responses to exercise in running birds. A prior period of training is necessary to accustom the birds to laboratory procedures.
• 4.4. The possible neural and/or humoral mechanisms controlling exercise hyperpnea are listed. Intrapulmonary hypocapnia seems to exclude the possibility that lung chemoreceptors are responsible for the hyperpnea during exercise, but these receptors probably play a predominant role in the determination of ventilatory pattern.

     

The influence of anaerobiosis on the levels of adenosine nucleotides and some glycolytic metabolites in tubifex sp. (annelida,oligochaeta)

• 1.1. In Tubifex sp. the amounts of ATP, ADP and AMP, and of glucose, glucose-1-P, glucose-1-P, glucose-6-P, fructose-6-P and fructose-1, 6-P were measured after experimental anaerobiosis.
• 2.2. The energy charge decreased from 0.84 to 0.07/0.69 within 6–9 hr of anaerobiosis.
• 3.3. During long term anaerobiosis there was no change from 0.70/0.69.
• 4.4. The concentrations of glucose, glucose-6-P and fructose-1,6-P increased somewhat during an initial phase of anaerobiosis.
• 5.5. The data are discussed with respect to the regulation of energy metabolism, especially during the transition of aerobic to anaerobic metabolism.
• 6.6. It is concluded that this transition is accomplished within 6–12 hours.

     

The energy costs of temperature regulation in birds: The influence of quick sinusoidal temperature fluctuations on the gaseous metabolism of the japanese quail (Coturnix coturnix japonica)

• 1.1. Quick sinusoidal temperature fluctuations (constant average 10°C) cause an increase in metabolism in comparison to an invariable constant ambient temperature of the same dimension.
• 2.2. At the observed mean value of 10°C metabolism is increased by 0.8% per 1 K/hr based on the values of resting metabolic rate (correlation: M = 53.5 + 0.445 T_a, M in J/K g hr, T_a = ambient temperature change in K/hr) and 0.6% based on the values of activity metabolism (M = 70.4 + 0.425 T_a).
• 3.3. The absolute augmentation of metabolism per 1 K/hr is, by comparison, the same for day and night. Its amount is 0.42 and 0.43 J/K g hr respectively.
• 4.4. In the response of metabolism to temperature fluctuations no differences could be found with respect to the amplitude and frequency modifications of temperature.
• 5.5. The increase of energy consumption is probably caused to a greater extent by “overshoot” of the feedback control system in the course of adjusting metabolism to new levels according to the ambient temperature conditions.
• 6.6. Short term ambient temperature changes (i.e. measuring different temperature levels in one night to test basic metabolism vs ambient temperature) cannot produce reasonable values for basic metabolic rate, since these artificially high values reflect the testing procedure.

     

Analysis of the circadian rhythm in energy metabolism of rat liver

• 1.1. To study the temporal organization of energy metabolism in rat liver the steady state concentrations of key intermediates of carbohydrate and phosphorus metabolism were determined during 24 hr.
• 2.2. The circadian rhythm in energy metabolism of rat liver has been analysed by four different approaches. It was shown that neither apparent PEP synthesis nor crossover theorem were acceptable for the elucidation of the temporal organization of multi-enzyme systems.
• 3.3. Correlations analysis explained the temporal organization of energy metabolism most satisfactorily.
• 4.4. Based on the results of this analysis it was suggested that circadian regulation of energy metabolism in liver was realized at the level of the citric acid cycle.

     

Changes in high-energy phosphate metabolism in the water scorpion,Ranatra chinensis,under cold water-warm water stress

• 1.1. To evaluate changes in high-energy phosphate metabolism in the water scorpion (Ranatra chinensis) under restraint and cold water-warm water stresses, in vivo [³¹P]NMR spectra were obtained.
• 2.2. Under restraint stress, arginine phosphate (Arg-P) decreased by 10% after 1 hr and remained at that level thereafter, while β-ATP showed negligible changes over 6 hr.
• 3.3. As the water temperature gradually increased or decreased, the relative concentration of Arg-P decreased due to enzyme regulation.
• 4.4. Repeated cold water-warm water stress, which consisted of repeated 15 min exposures to cold water (5°C) followed by 15 min exposures to warm water (30°C) caused distinct decreases in Arg-P and β-ATP concentration. These decreases were dependent on the frequency of exposure.
• 5.5. Phosphomonoesters (PME) increased not only with restraint stress but also with cold water-warm water stress.
• 6.6. The effect of cold water-warm water stress on high-energy phosphate metabolism was greater than that of restraint stress.

     

Effects of the nonsteroidal anti-inflammatory drug piroxicam on energy metabolism in the perfused rat liver

• 1.1. The actions of piroxicam, a nonsteroidal and noncarboxylic anti-inflammatory drug, on the metabolism of the isolated perfused rat liver were investigated. The main purpose was to verify if piroxicam is also active on glycogenolysis and energy metabolism, as demonstrated for several carboxylic nonsteroidal anti-inflammatories.
• 2.2. Piroxicam increased oxygen consumption in livers from both fed and fasted rats.
• 3.3. Piroxicam increased glucose release and glycolysis from endogenous glycogen (glycogenolysis).
• 4.4. Gluconeogenesis from lactate plus pyruvate was inhibited.
• 5.5. The action of piroxicam on oxygen consumption was blocked by antimycin A, but not by atractyloside.
• 6.6. The action of piroxicam in the perfused rat liver metabolism seems to be a consequence of its action on mitochondria.
• 7.7. It can be concluded that inhibition of energy metabolism and stimulation of glycogenolysis are not specific properties of carboxylic nonsteroidal anti-inflammatory drugs.

     

Glycolytic enzymes of fowl and turkey spermatozoa

• 1.1. It was confirmed that, under anaerobic conditions, fowl spermatozoa formed lactate from glucose thirteen times faster than turkey spermatozoa.
• 2.2. The profiles of glycolytic enzyme activities were similar for spermatozoa from both species; however fowl spermatozoal activities were generally 2- to 4-fold higher.
• 3.3. Exceptions were glycerophosphate mutase and lactate dehydrogenase activities which were respectively 9.5 and 41 times greater in fowl spermatozoa.
• 4.4. In both species, spermatozoal glyceraldehyde-3-phosphate dehydrogenase had the lowest activity of the glycolytic enzymes.

     

A two-peak circadian system in body temperature and activity in the domestic cat,Felis catus L.

• 1.1.|The body temperature and activity of cats exhibit two-peak patterns during the 24 hr period.
• 2.2.|The two peaks are retained when the temperature and activity are permitted to freerun.
• 3.3.|A third prominent peak appears in the actograms in cats in the main colony, induced by the presence of humans.

     

Erg circadian rhythm in the course of ontogeny in crayfish

• 1.1. The objective of the present work was to study the ontogeny of the ERG circadian rhythm in crayfish.
• 2.2. Long-term recordings of ERG and shielding retinal pigments position measured from the instar, the second instar, the third instar and the adult crayfish were obtained.
• 3.3. In the youngest animals (1–8 days old) an ultradian rhythm (15min-4hr periods) in the ERG amplitude was detected.
• 4.4. Older animals showed a progressive increment in the period length before they exhibited a circadian pattern. This last appeared, the first time, in 30-day-old animals and showed noticeable differences in the adult crayfish. At the same time, the crayfish began to show photomotor reflex. Later on (140-day-old crayfish) the circadian rhythm attained its final parameters.
• 5.5. The SD was used as a measure of lability in periods. The 4 hr ultradian rhythm and the 22.4 hr circadian rhythm showed the lowest SD indicating that they are the most precise period values.
• 6.6. Our results support the idea that the ERG circadian rhythm results from the coupling among high frequency (ultradian) oscillators, particularly those of 4 hr periods and that the coupling depends on the action of neurosecretions released from the sinus gland.

     

Serotonin or electrical optic nerve stimulation increases the photosensitivity of the Aplysia eye

• 1.1. Exposure of isolated Aplysia eyes to serotonin (10⁻⁷ M) produces large and long-lasting (hours) increases in the ERG recorded from the surface of the eye.
• 2.2. Dopamine, octopamine, or acetylcholine do not mimic the effect of 5-HT on the ERG.
• 3.3. Brief electrical optic nerve stimulation (2 Hz, 2 min) also increases the ERG and this effect also lasts a long period of time (0.5–2 hr).
• 4.4. Our results suggest that serotonin increases the response of photoreceptor cells to light and that efferent optic nerve activity may modulate photosensitivity through release of serotonin in the eye.

     

Gas tensions within the egg of the quail (Coturnix c. Japonica) during the closing stages of embryonic development

• 1.1. The respiratory status of the embryonic quail during the two days prior to hatching was assessed by measuring the gas tensions within the air space of the egg and of blood collected from the chorioallantois.
• 2.2. When the lungs became inflated there was a significant decrease in the pO₂ of the gas in the air space.
• 3.3. After pipping, there was a rise in the pO₂ and fall in the pCO₂ within the air space, together with corresponding changes in the blood.
• 4.4. The outer shell membrane remained intact until the onset of hatching.
• 5.5. These results were compared with those obtained by other workers using the domestic fowl.