The Respiratory Exchange of the Desert Locust (Schistocerca Gregaria) before, During and After Flight

1951 ◽  
Vol 28 (3) ◽  
pp. 344-357 ◽  
Author(s):  
AUGUST KROGH ◽  
TORKEL WEIS-FOGH
Keyword(s):  
Oxygen Consumption ◽  
Schistocerca Gregaria ◽  
Ketone Bodies ◽  
Relative Rate ◽  
Unexpected Result ◽  
Desert Locust ◽  
Average Value ◽  
Short Period ◽  
Before And After ◽  
Small Container

The respiratory exchange of mature males of the Desert Locust Schistocerca gregaria (Forskål) has been studied during tethered flight in a small container and compared with the exchange before and after flights of varying duration. All determinations were based on gas analyses, and so the CO2 output and the O2 uptake were determined simultaneously. The accuracy of the analytical procedure has been discussed and the determinations of the R.Q. before and during flight found to be valid. The figures of the oxygen consumption are reduced to N.T.P. 1. During rest at 27-30°C the oxygen consumption amounted to 0.63 l. O2/kg./hr., which means that an average male of 1.8 g. consumed 18 cu.mm. O2 per min. During flight, however, the consumption increased fifteen to fifty times, the corresponding figures being 10-30 l. O2/kg./hr. or 300-900 cu.mm. O2 per min. in an average male. 2. After even a short period (10 min.) of flight in a roundabout or in front of a wind tunnel a distinct ‘oxygen debt’ was demonstrated. After prolonged flight (90-195 min.) the ‘debt’ was nearly doubled. It corresponded to 0.3-0.7 l. O2/kg. or to the oxygen consumption during only 0.5-1.5 min. of flight, so that anaerobic processes could not amount to much. It was characteristic that the recovery lasted at least 1 hr. 3. The R.Q. in resting animals averaged 0.82, and during the first 30 min. of flight the same value was obtained, but during the following 60 min. a statistically significant decrease of the R.Q. could be demonstrated, the average value in this period being 0.75. This unexpected result strongly indicates that, unlike other insects investigated so far, locusts utilize mainly fat as a source of energy during sustained flight. 4. It is suggested that a surplus of ketone bodies caused by the intensive breakdown of fats might explain the prolonged recovery of 1-2 hr. duration in Schistocerca, the recovery after flight in Drosophila which fly on carbohydrate lasting only 2 min. or less in spite of the same relative rate of combustion.

scholarly journals Rates of utilization and fates of glucose, glutamine, pyruvate, fatty acids and ketone bodies by mouse macrophages

1987 ◽  
Vol 242 (3) ◽  
pp. 631-636 ◽  
Author(s):  
P Newsholme ◽  
S Gordon ◽  
E A Newsholme
Keyword(s):  
Fatty Acids ◽  
Oxygen Consumption ◽  
Ketone Bodies ◽  
Energy Requirement ◽  
Peritoneal Macrophages ◽  
Secretory Proteins ◽  
Short Period ◽  
Resting Lymphocytes ◽  
Almost All

The concentrations of ATP and the ATP/AMP concentration ratios were maintained in thioglycollate-elicited mouse peritoneal macrophages incubated in vitro for 90 min in the presence or absence of added substrate: rates of glycolysis, lactate formation and glutamine utilization were approximately linear with time for at least 60 min of incubation. The rate of oxygen consumption by macrophages was only increased above the basal rate (i.e. that in the absence of added substrate) by addition of succinate or pyruvate, or by addition of the uncoupling agent carboxyl cyanide m-chlorophenylhydrazone (‘CCCP’); it was decreased by 75% by the addition of KCN. These findings suggest that metabolism of endogenous substrate can provide most, if not all, of the energy requirement of these cells, at least for a short period. The rates of glucose and glutamine utilization by incubated macrophages were approx. 300 and 100 nmol/min per mg of protein respectively. A large proportion of the glutamine that is utilized is converted into glutamate and aspartate, and very little (perhaps less than 10%) is oxidized. Similarly almost all of the glucose that is utilized is converted into lactate and very little is oxidized. This characteristic is similar to that of resting lymphocytes and rapidly dividing cells; in non-proliferating macrophages it may be a mechanism to provide precision in control of the rate of biosynthetic processes that utilize intermediates of these pathways, e.g. purines and pyrimidines for mRNA for the synthesis of secretory proteins and glycerol 3-phosphate for phospholipid synthesis for membrane recycling. No utilization of acetoacetate or 3-hydroxybutyrate by macrophages was detected. In contrast, both butyrate and oleate were oxidized. The rate of [14C]oleate conversion into 14CO2 (1.3 nmol/h per mg of protein) could account for most of the oxygen consumption by incubated macrophages, suggesting that long-chain fatty acids might provide an important fuel in situ. This may be one explanation for the secretion of lipoprotein lipase by these cells, to provide fatty acids for oxidation from the degradation of local triacylglycerol.

Group effects on feeding in adult males of the desert locust, Schistocerca gregaria (Forsk.), in relation to sexual maturation.

1961 ◽  
Vol 51 (4) ◽  
pp. 731-753 ◽  
Author(s):  
Maud J. Norris
Keyword(s):  
Sexual Maturation ◽  
Schistocerca Gregaria ◽  
Adult Life ◽  
Early Period ◽  
Desert Locust ◽  
Adult Males ◽  
Young Males ◽  
Full Effect ◽  
Short Period ◽  
Early Maturing

It has previously been shown that the sexual maturation of males of Scliistocerca grcgaria (Forsk.) is accelerated by crowding with other individuals of similar or greater age, and that the maturation of males kept in single pairs with older mature males is accelerated as compared with that of isolated males or males kept in single pairs with other young males or females of their own age. The effects of these groupings on the levels of feeding and excretion are investigated in the present work.Crowded males ate and excreted more than isolated ones during the first ten days of adult life. Five males in a 9-litre cage are sufficient to induce almost the full effect of crowding, and marked effects are shown when only two males are present in such a cage.After the second or third week, the level of feeding declines. This occurs earlier in early-maturing individuals, so that for a short period the crowded males eat little more or even less than the isolated ones. When the isolated males in their turn become mature their feeding again falls slightly below that of the crowded ones. When all males are isolated, there is a significant tendency for those males which eat least from the beginning of adult life and which increase their weight least to become mature earliest.The proportion of the food utilised was not affected by density. It was higher during the early period of maximum consumption than it was after the level of feeding declined.

scholarly journals The secretion of the eggshell of Schistocerca gregaria: ultrastructure of the follicle cells during the termination of vitellogenesis and eggshell secretion

1980 ◽  
Vol 46 (1) ◽  
pp. 455-477
Author(s):  
S.J. Kimber
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Schistocerca Gregaria ◽  
Follicle Cells ◽  
Vitelline Membrane ◽  
Desert Locust ◽  
Golgi Bodies ◽  
Short Period ◽  
Distinct Morphology ◽  
Dense Product

The secretion of the eggshell by the follicle cells in the desert locust, Schistocerca gregaria, was studied using the electron microscope. The 3 layers of the eggshell, the vitelline membrane, the endochorion, and the exochorion, are produced in sequence over a short period of about 30–36 h. The follicle cells contain little rough endoplasmic reticulum (RER) and small inconspicuous Golgi bodies during vitellogenesis. As eggshell secretion approaches there is an increase in the amount of RER and Golgi cisternae contain electron-dense product. At each stage of the 3-phase secretion cycle the follicle cells contain Golgi bodies and secretion vesicles with distinct morphology. The follicle cells increase in breadth and decrease in height between the beginning and end of eggshell secretion. The endochorion ridges arise at the junction between follicle cells and appear to be moulded by the microvilli formed at this position. In the ovary prior to ovulation, the eggshell consists of a thin (0.5 micrometer) electron-dense vitelline and an outer fibrillar exochorion layer, 20–30 micrometer thick. Further changes take place in the vitelline membrane and the endochorion after oviposition, and a layer of curly fibres, the extrachorion, is secreted in the oviduct.

Oxygen Consumption in Platelets of Newborn Infants before and after Stimulation by Thrombin.

1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta
Keyword(s):  
Oxygen Consumption ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Newborn Infant ◽  
Umbilical Cord Blood ◽  
Newborn Infants ◽  
O2 Consumption ◽  
Adult Control ◽  
Healthy Newborn ◽  
Before And After

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.

GESTOGENS IN CORPUS LUTEUM OF CATTLE

1960 ◽  
Vol XXXIII (III) ◽  
pp. 417-427 ◽  
Author(s):  
John Kristoffersen
Keyword(s):  
Corpus Luteum ◽  
Average Value ◽  
Spectrophotometric Methods ◽  
The Third ◽  
Quantitative Measurements ◽  
Before And After ◽  
Luteal Tissue ◽  
In Pregnancy

ABSTRACT By means of chromatographic and spectrophotometric methods progesterone and a substance closely similar to 20β-hydroxy-pregn-4-ene-3-one has been detected in luteal tissue from non-pregnant and pregnant cows. In 21 animals quantitative measurements based on a method giving an average net recovery of 56 per cent showed that in pregnancy the average progesterone content in the corpus luteum reached a maximum in the third to fifth month, with low values before and after this period. For 6 nonpregnant cows, the average value was 20.2 μg/g tissue, which is considerably higher than previous values reported in the literature. The relation between these findings and the bovine dependence on a functional corpus luteum in pregnancy is discussed, and it is pointed out that more information about the metabolism of progesterone in cattle is highly desirable.

Sign in / Sign up

Export Citation Format

Share Document