scholarly journals Lack of dynein arms in immotile human spermatozoa.

1975 ◽  
Vol 66 (2) ◽  
pp. 225-232 ◽  
Author(s):  
B A Afzelius ◽  
R Eliasson ◽  
O Johnsen ◽  
C Lindholmer
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Genetic Disorder ◽  
Lactic Acid Production ◽  
Sperm Head ◽  
Conventional Model ◽  
Fibrous Sheath ◽  
Sperm Tail ◽  
Ultrastructural Appearance ◽  
Dynein Arms

Sermatozoa from two brothers who are not twins were found to be straight and immotile. Examinations of the sperm showed that oxygen consumption and lactic acid production were normal; viability tests showed that the percentage of dead sperm was not increased. The ultrastructural appearance of the sperm tail was normal except for a complete lack of dynein arms and some irregularities in the arrangement of the accessory fibers and the longitudinal columns of the fibrous sheath. The mitochondrial apparatus and the sperm head conform to the conventional model. According to the sliding-filament hypothesis first proposed by Afzelius (1959. J. Biophys. Biochem. Cytol. 5:269.), the arms are responsible for the bending movements of the tail. The simplest explanation for the simultaneous lack of arms and sperm motility appears to be that the two brothers have a genetic disorder involving production, assembly, or attachment of the dynein arms.

scholarly journals Respiration and Glycolysis of Normal Human Lymphocytes

Blood ◽  
1966 ◽  
Vol 28 (2) ◽  
pp. 163-174 ◽  
Author(s):  
CARL J. HEDESKOV ◽  
VIGGO ESMANN
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Acid Production ◽  
Glucose Utilization ◽  
Aerobic Glycolysis ◽  
Human Lymphocytes ◽  
Lactic Acid Production ◽  
Crowding Effect ◽  
Normal Human

Abstract The metabolism of intact, normal, human lymphocytes in vitro was studied from a total of 80 subjects. Corrected for the metabolism of contaminating red blood cells, the glucose uptake, lactic acid production, and oxygen consumption were 62, 95, and 117 µmoles per 1010 lymphocytes per hour, respectively, provided the cells were incubated at concentrations greater than 40 x 106 lymphocytes per ml. At lower lymphocyte concentrations the oxygen consumption per lymphocyte rose steeply with decreasing cell concentration (crowding effect). A similar but weaker crowding effect was noted for the lactic acid production, but not for the utilization of glucose. The oxygen uptake was lower with 20 per cent than with 100 per cent oxygen as gas phase. Small Pasteur and Crabtree effects were demonstrated. The oxygen consumption and lactic acid production proceeded linear with time, while the glucose utilization was higher during the first 30 minutes of incubation than later on. It is concluded that lymphocytes have a low aerobic glycolysis accounting for 75 per cent of the glucose utilization. The respiration is severely inhibited at high cell concentrations and it is suggested that this is caused by an insufficient availability of oxygen to the cells.

scholarly journals Characterization of different oligomeric forms of CRISP2 in the perinuclear theca versus the fibrous tail structures of boar spermatozoa

2021 ◽  
Author(s):  
M Zhang ◽  
E G Bromfield ◽  
T Veenendaal ◽  
J Klumperman ◽  
J B Helms ◽  
...  
Keyword(s):  
Protein Complexes ◽  
Protein Structures ◽  
Biochemical Properties ◽  
Sperm Head ◽  
Fibrous Sheath ◽  
Sperm Tail ◽  
Reducing Conditions ◽  
Outer Dense Fibers ◽  
Perinuclear Theca

Abstract Mammalian sperm carry a variety of highly condensed insoluble protein structures such as the perinuclear theca, the fibrous sheath and the outer dense fibers, which are essential to sperm function. We studied the role of cysteine rich secretory protein 2 (CRISP2); a known inducer of non-pathological protein amyloids, in pig sperm with a variety of techniques. CRISP2, which is synthesized during spermatogenesis, was localized by confocal immunofluorescent imaging in the tail and in the post-acrosomal region of the sperm head. High resolution localization by immunogold labeling electron microscopy (EM) of ultrathin cryosections revealed that CRISP2 was present in the perinuclear theca and neck region of the sperm head, as well as in the outer dense fibers and the fibrous sheath of the sperm tail. Interestingly, we found that under native, non-reducing conditions CRISP2 formed oligomers both in the tail and the head but with different molecular weights and different biochemical properties. The tail oligomers were insensitive to reducing conditions but nearly complete dissociated into monomers under 8 M urea treatment, while the head 250 kDa CRISP2 positive oligomer completely dissociated into CRISP2 monomers under reducing conditions. The head specific dissociation of CRISP2 oligomer is likely a result of the reduction of various sulfhydryl groups in the cysteine rich domain of this protein. The sperm head CRISP2 shared typical solubilization characteristics with other perinuclear theca proteins as was shown with sequential detergent and salt treatments. Thus, CRISP2 is likely to participate in the formation of functional protein complexes in both the sperm tail and sperm head, but with differing oligomeric organization and biochemical properties. Future studies will be devoted to the understand the role of CRISP2 in sperm protein complexes formation and how this contributes to the fertilization processes.

THE EFFECT OF CARBON MONOXIDE ON OXYGEN CONSUMPTION, GLUCOSE UTILIZATION, AND GROWTH IN MAMMALIAN CELLS IN VITRO

1959 ◽  
Vol 37 (5) ◽  
pp. 623-638 ◽  
Author(s):  
Samuel Dales ◽  
Kenneth C. Fisher
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Lactic Acid ◽  
Acid Production ◽  
Mammalian Cells ◽  
Lactic Acid Production ◽  
Absorption Bands ◽  
Gas Uptake ◽  
L Cells

The effect of carbon monoxide on respiration, growth, and carbohydrate metabolism of Earle's L strain cells was investigated. The rate of gas uptake by suspensions of cells in a Warburg respirometer was the same from mixtures containing various proportions of CO/O2/N2 or containing only O2/N2. Apparently carbon monoxide was not inhibiting oxygen consumption. In respirometers filled with carbon monoxide and oxygen in the ratio of 9:1, illumination caused the net gas uptake to rise 23% above that of the controls. This suggests that the rate of oxygen consumption in the dark was reduced as a consequence of an inhibition of a respiratory enzyme by carbon monoxide. In keeping with this suggestion, a spectroscopic examination revealed the presence in L cells of absorption bands corresponding to those of the cytochrome enzymes. Using differential manometers it was established for the first time that carbon monoxide is taken up by L cells in the dark. It is concluded that a fraction of the gas uptake which is represented by the consumption of oxygen associated with normal metabolism must be reduced in the presence of carbon monoxide. It is also concluded that L cells oxidize carbon monoxide to carbon dioxide. The rate of multiplication of cells was reduced by carbon monoxide while the rate of glucose breakdown and lactic acid production were markedly accelerated, suggesting that there was an inhibition of cytochrome oxidase. Low partial pressures of oxygen also reduced the rate of multiplication of L cells while increasing the rate of glucose disappearance and the rate of lactic acid production. The observations reported here thus emphasize the role of aerobic oxidations in the maintenance of the maximum rate of growth.

Kinetics and mechanism of oxygen debt contraction in man

1963 ◽  
Vol 18 (2) ◽  
pp. 371-377 ◽  
Author(s):  
R. Margaria ◽  
P. Cerretelli ◽  
P. E. diPrampero ◽  
C. Massari ◽  
G. Torelli
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Linear Function ◽  
Pyruvic Acid ◽  
Lactic Acid Production ◽  
Maximum Level ◽  
Oxygen Debt ◽  
Rate Of Increase ◽  
Intensity Of Exercise ◽  
Very High

Oxygen consumption, along with lactic and pyruvic acid in blood, have been measured throughout the performance of heavy muscular exercise of different intensities, all leading to exhaustion in 1–10 min. Oxygen consumption increases exponentially with time; the maximum level attained seems to be independent of the intensity of exercise except in exercises of very high intensity and short duration, when it seems to be slightly increased. The rate of increase of oxygen consumption increases with the intensity of exercise. Pyruvic acid in blood increases exponentially also, and a steady state is reached at a level which tends to be higher, the heavier the exercise. Lactic acid increases as a linear function of time, the line eventually flattening down only toward the end of the exercise when the maximal values of lactic acid are reached. The lactic acid increase, grams per minute, is a linear function of the intensity of exercise; no lactic acid is produced if the exercise is below 220 cal/kg min, or a higher value for athletes. The caloric equivalent of lactic acid production from glycogen can be calculated at about 222 cal/g. This value in man is discussed in relation to previous values given. The kinetic of the lactic acid increase during exercise is in agreement with the hypothesis of an additional (alactacid) mechanism of oxygen debt contraction. Submitted on July 31, 1962

scholarly journals STUDIES ON THE INTERACTION BETWEEN PHAGOCYTES AND TUBERCLE BACILLI

1956 ◽  
Vol 104 (1) ◽  
pp. 121-136 ◽  
Author(s):  
Hartmann Stähelin ◽  
Emanuel Suter ◽  
Manfred L. Karnovsky
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Lactate Production ◽  
Dry Weight ◽  
Cell Types ◽  
Polymorphonuclear Leucocytes ◽  
Cell Counts ◽  
Mononuclear Leucocytes

As a basis for studies on the interaction of phagocytes and tubercle bacilli experiments were carried out to obtain information on some biochemical characteristics of exudate leucocytes from guinea pigs. It was found that total cellular phosphorus was the most suitable measure of protoplasm. Cell counts were less reliable because of unavoidable clumping in the suspension, and dry weight measurements were less specific when contamination with erythrocytes occurred. The utility of phosphorus measurements in this connection depends upon the fact that an erythrocyte contains only 4 per cent of the phosphorus present in a leucocyte. From measurements on mixed suspensions consisting of varying known proportions of polymorphonuclear and mononuclear leucocytes as determined by differential counting, it was possible to compute true values for these two cell types with respect to oxygen consumption and lactic acid production. Thus it was found that monocytes consumed considerably more oxygen and produced more lactate than polymorphonuclear leucocytes. From the data obtained it is suggested that differences in metabolic activity found when comparing cell suspensions obtained by the use of different irritants are due to different proportions of the two cell types. In particular, the effects of oxygen tension and pH on the activities of the cells were studied. It was found that decreasing the proportion of oxygen in the atmosphere from that of air to 1 per cent reduced oxygen consumption by about 80 per cent, whereas lactic acid production was increased by about 45 per cent. It was also found that decreasing the pH of the medium below pH 7.5 caused a considerable reduction in the respiration, lactate production, and viability of polymorphonuclear leucocytes. The monocytes proved less sensitive to similar changes in pH, especially with regard to lactic acid production and viability. Observations were made of oxygen consumption and lactate production during phagocytosis. During the hour following the addition of heat-killed tubercle bacilli to the phagocytes, the oxygen consumption of suspensions rich in polymorphonuclear leucocytes rose by 60 per cent, and that of suspensions rich in monocytes rose by nearly 100 per cent. Lactic acid production was unchanged during phagocytosis.

THE METABOLISM OF GLUCOSE BY RAT UTERUS TISSUE IN EARLY PREGNANCY

1971 ◽  
Vol 66 (1) ◽  
pp. 16-24 ◽  
Author(s):  
M. A. H. Surani ◽  
P. J. Heald
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Oxygen Uptake ◽  
Acid Production ◽  
Energy Requirement ◽  
Lactic Acid Production ◽  
Uterine Tissue ◽  
Rat Uterus ◽  
Marked Decline

ABSTRACT The oxygen uptake, lactic acid production and differential production of CO2 from [1-14C] glucose and [6-14C] glucose were examined in rat uterine tissue in vitro during the first nine days of pregnancy. After implantation had occurred the uterine areas containing the implanted blastocysts were studied separately from the remaining areas. It was found that the oxygen consumption of the tissues remained reasonably constant until day 7 of pregnancy and thereafter declined markedly in tissues from implanted areas and non implanted areas when expressed in terms of dry wt. When calculated on a DNA basis, the oxygen consumption of the implanted tissue still showed a marked decline by day 9 of pregnancy, whereas that of the non implanted tissue increased. Lactic acid production increased strongly in the implanted tissue but showed little change in the non implanted areas. The C1/C6 ratio increased significantly on day 3 of pregnancy and was consistantly and significantly higher in the implanted tissue in the non implanted tissue. The results are discussed in terms of the energy requirement for implantation.

THE EFFECT OF CARBON MONOXIDE ON OXYGEN CONSUMPTION, GLUCOSE UTILIZATION, AND GROWTH IN MAMMALIAN CELLS IN VITRO

1959 ◽  
Vol 37 (1) ◽  
pp. 623-638 ◽  
Author(s):  
Samuel Dales ◽  
Kenneth C. Fisher
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Lactic Acid ◽  
Acid Production ◽  
Mammalian Cells ◽  
Lactic Acid Production ◽  
Absorption Bands ◽  
Gas Uptake ◽  
L Cells

The effect of carbon monoxide on respiration, growth, and carbohydrate metabolism of Earle's L strain cells was investigated. The rate of gas uptake by suspensions of cells in a Warburg respirometer was the same from mixtures containing various proportions of CO/O2/N2 or containing only O2/N2. Apparently carbon monoxide was not inhibiting oxygen consumption. In respirometers filled with carbon monoxide and oxygen in the ratio of 9:1, illumination caused the net gas uptake to rise 23% above that of the controls. This suggests that the rate of oxygen consumption in the dark was reduced as a consequence of an inhibition of a respiratory enzyme by carbon monoxide. In keeping with this suggestion, a spectroscopic examination revealed the presence in L cells of absorption bands corresponding to those of the cytochrome enzymes. Using differential manometers it was established for the first time that carbon monoxide is taken up by L cells in the dark. It is concluded that a fraction of the gas uptake which is represented by the consumption of oxygen associated with normal metabolism must be reduced in the presence of carbon monoxide. It is also concluded that L cells oxidize carbon monoxide to carbon dioxide. The rate of multiplication of cells was reduced by carbon monoxide while the rate of glucose breakdown and lactic acid production were markedly accelerated, suggesting that there was an inhibition of cytochrome oxidase. Low partial pressures of oxygen also reduced the rate of multiplication of L cells while increasing the rate of glucose disappearance and the rate of lactic acid production. The observations reported here thus emphasize the role of aerobic oxidations in the maintenance of the maximum rate of growth.

Sign in / Sign up

Export Citation Format

Share Document