Sperm motility index: a new parameter for human sperm evaluation

OBJECTIVE

The study was performed to evaluate the correlation between sperm motility index, a novel parameter of semen quality, and routine semen analysis parameters by microscopic evaluation.

DESIGN

Sperm motility index was measured by an electro-optical device, the Sperm Quality Analyzer (United Medical Systems Inc., Santa Ana, CA). Human semen samples covering the whole span of qualities were analyzed prospectively and simultaneously by both methods.

SETTING

Samples were collected from patients referred to university hospital infertility clinics.

PATIENTS, PARTICIPANTS

Nine hundred sixty-eight semen samples of 812 patients and healthy men were analyzed.

MAIN OUTCOME MEASURE(S)

Sperm motility index is a measurement of optical density fluctuations caused by motile cells; therefore, a positive correlation was anticipated between its values and semen motility parameters.

RESULTS

Sperm motility index values demonstrated statistically significant correlation with motile cell concentration, total cell concentration, and percent motile cells. They were also shown to reliably represent semen quality assessment obtained by two experienced andrologists.

CONCLUSIONS

The sperm motility index provides a reliable and objective reflection of semen motility parameters and quality.

Age dependence of steady state mitochondrial oxidative metabolism in the in vivo hypoxic dog brain

Mitochondrial bioenergetics were investigated in newborn, neonatal and adult dog brains during normoxia and hypoxia. The ratio of the rate of ATP synthesis to the maximum synthesis rate (V/Vmax), phosphorylation potential, [ADP] and PCr/Pi, were used to evaluate age related mitochondrial hypoxic tolerance. These indicators were calculated from the phosphorus compounds measured by in vivo 31P MRS quantitatively using ATP as an internal reference. Indicators and substrates of mitochondrial function, V/Vmax, ADP, and Pi reached a peak value during the neonatal (3-21 days) period of development, suggesting that the oxidative metabolism of the neonate is more vulnerable to stress when compared to newborns and adults. Distinction among newborns and neonates became apparent during hypoxia. Newborns (0-2 days old) showed substantial tolerance by maintaining V/Vmax until exposure to severe hypoxia. Older neonates (3-21 days old) showed increases in V/Vmax, [Pi] and [ADP] under less than severe conditions of hypoxia. Adults exhibited low V/Vmax values even during exposure to severe hypoxia, further indicating that mitochondrial oxidative processes are more stable in adults than in newborns and neonates. This study provides evidence that newborns and adults are more capable of maintaining mitochondrial function under conditions of minimal to moderate hypoxia than 3-21 day old neonates.

Oscillations of cortical oxidative metabolism and microcirculation in the ischaemic brain

A new in vivo model for studying brain metabolic and haemodynamic oscillatory phenomena during ischaemia is described. In this model acute or chronic occlusion of one or two carotid arteries in the rat is performed. Due to the partial ischaemia developed, oscillations in the level of intramitochondrial pyridine nucleotides (NADH) as well as flavoproteins (Fp) were recorded from the brain by monitoring the fluorescence of these respiratory chain components. The two fluorescent signals (NADH and Fp) were measured by using the time sharing or DC fluorometer/reflectometer. The changes in the reflected light at the excitation wavelengths (366 and 450 nm) were recorded simultaneously. Bilateral carotid artery occlusion induced immediate oscillations (6-9 waves per min) in the mitochondrial redox state as well as in tissue blood volume in both hemispheres. To verify the accuracy of the NADH monitoring system, including the correction technique for haemodynamic and other artifacts, we used the intracarotid artery saline bolus injection approach. The results could be summarized as follows: (1) unilateral carotid artery occlusion resulted in delayed development of oscillations, particularly in the ipsilateral hemisphere; (2) the oscillation phenomenon was reversible if recirculation restarted within 5 min. Occlusion for more than 30 min resulted in irreversible oscillations; (3) the oscillation appearances and intensities were affected by various physiological conditions. Vasoconstriction, induced by hyperoxia, stimulated the oscillations while vasodilation, induced by hypercapnia, depressed them. Anoxia, hypoxia and spreading depression (SD) abolished the oscillations. Glucose injection was not effective.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo mechanisms of myocardial functional stability during physiological interventions

Metabolic regulatory mechanisms are designed to maintain stable myocardial function during extremes in physiological insult; they can now be studied in vivo and may provide insight into mechanisms of altered myocardial functional decompensation during disease processes. To determine mechanisms of myocardial stability during hypoxia and acute pressure loading, creatine kinase (CK) kinetics (forward rate constant, Kf, and flux of phosphocreatine, PCr, to adenosine triphosphate, ATP), and nicotinamide adenine dinucleotide (NADH) redox state were determined with 31P nuclear magnetic resonance (NMR) and NADH fluorometry, respectively, and correlated with heart work (heart rate x systolic blood pressure, HR x SBP), cardiac output (CO) and O2 consumption (MVO2) in 15 anesthetized open chest dogs. Hypoxia (PaO2 of 30-35 mm Hg) was produced in 6 dogs with an inspired O2/N2 of 200/3,000. Cardiac loading was produced in 9 dogs by administration of norepinephrine (NE, 1 micrograms/kg/min). Each dog acted as its own control. Baseline NADH fluorometry, 31P-NMR saturation transfer and cardiac function measurements were performed simultaneously in each dog, after which the experimental interventions were made. Similar increases in HR x SBP, CO, and MVO2 which occurred during both interventions were associated with different bioenergetic responses. During NE infusion, the Kf of CK increased from control; during hypoxia, the Kf decreased from control (p less than 0.05). Flux of PCr----ATP was significantly lower during hypoxia than during NE infusion (p less than 0.05). PCr was decreased significantly during NE infusion (p less than 0.05). In addition, NADH redox state increased (from baseline of 100%) during hypoxia (140 +/- 10%) and decreased during NE infusion (78 +/- 6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Brain mitochondrial redox state, tissue haemodynamic and extracellular ion responses to four-vessel occlusion and spreading depression in the rat

Fibre-optic surface fluorometer reflectrometry was used to monitor the NADH (nicotine adenine dinucleotide) redox state from rat brain during three- or four-vessel occlusion. To compare the completeness of the electrocauterization of the vertebral arteries and the effectiveness of the anterior cerebral arteries, two light guides were implanted above the cerebral hemispheres. The NADH level was measured and correlated with the changes in the intensity of the reflected light at the excitation wavelength (366 nm) and to the ECoG (electrocorticogram). In the present study, we used ten rats in which unilateral and bilateral carotid occlusion were performed. In a second group of rats we tested the effects of four-vessel occlusion on the metabolic and extracellular K+ and Ca2+ activities as compared with those recorded under spreading depression conditions. These experiments were done by using the multiprobe assembly (MPA) approach. The results could be summarized as follows: (1) in the four-vessel occlusion model, the level of cerebral ischaemia could be estimated quantitatively, in real-time, by monitoring the NADH redox state; (2) unilateral carotid occlusion (after vertebral coagulation) led to a variable level of ipsilateral ischaemia, depending upon the blood flow compensation between the two hemispheres; (3) fibre-optic fluorometry enabled the correlation of NADH redox state with other physiological parameters as well as during after-brain ischaemia; (4) using the MPA in rats exposed to four-vessel occlusion as well as spreading depression, we identified the differences between the two pathological states, although there were some similarities in the ion homeostasis responses.

Level of ischemia and brain functions in the Mongolian gerbil in vivo

The Mongolian gerbil (Meriones unguiculatus) provides a very useful animal model to study the effects of ischemia on brain functions. In this model it is possible to induce two levels of ischemia in the same animal. Thus, monitoring the brain in vivo in real-time will provide meaningful information regarding the development of ischemic injury as well as the follow-up during the recirculation period. The aims of the study were as follows: (1) To elucidate the mechanism behind the development of ischemic depolarization under unilateral and bilateral carotid artery occlusion. (2) To exclude the possibility that removal of the dura mater will affect the results. (3) To correlate the kinetics of the recovery processes to the level of ischemia. We tested the correlation between energy depletion level (evaluated by intramitochondrial NADH redox state) and the development of ischemic depolarization (ID) and vasospasm (evaluated by extracellular K+, DC potential and 366 nm reflectance changes, respectively) under partial and complete ischemia (induced by unilateral or bilateral carotid artery occlusion) using the multiparametric monitoring system (MPA). In 12 out of 32 gerbils monitored by the MPA, the dura mater remained intact, while in the other 20, it was removed very gently before connecting the MPA to the brain. Two types of responses to unilateral carotid artery occlusion were recorded and the gerbils were divided into groups according to the development of the ID. In a third group of 5 gerbils we tested the effect of 1-5 min of bilateral occlusion on the various parameters monitored.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral energy metabolism and oxygen state during hypoxia in neonate and adult dogs

The relationship between a noninvasive determination of relative oxygen saturation of Hb circulating in brain tissue (StO2) and energy metabolism was investigated with respect to age [dogs in three age groups (0 to 6-d-old, 7- to 21-d-old, and adults)] and to severity of brain hypoxia using double beam spectroscopy of Hb deoxygenation and nuclear magnetic resonance spectroscopy of energy metabolism. The in vivo oxy-Hb dissociation was determined from the relationship between StO2 curve in the adult dog brain and sagittal sinus oxygen partial pressure during graded hypoxemia and found to be sigmoidal with an oxygen dissociation constant of 26.6 mm Hg. This agreed with an in vitro determination for oxygen dissociation constant of 28.2 mm Hg in adult dog red cells. The arterial oxygen pressure at which brain StO2 was reduced by 50% was shifted toward the right with increasing age (22.2, 33.8, and 40.8 mm Hg, respectively). This correlated with an in vitro oxygen dissociation constant of red cell Hb of 17.0, 22.3, and 28.2 mm Hg in the three age groups, respectively. The phosphocreatine-inorganic phosphate ratio (PCr/Pi) was used to relate changes in cellular energy metabolism during hypoxia with changes in StO2. There was no change in PCr/Pi when StO2 had decreased to 50% of the control value. However, when the brain StO2 had decreased to between 7 and 15%, a reduction of PCr/Pi to 50% of the normoxic value occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Time resolved 3-dimensional recording of redox ratio during spreading depression in gerbil brain

Optical fluorescence and reflectance measurements have been used to map the distribution of metabolic states in three dimensions in the gerbil brain with a spatial resolution of 200 microns an a time resolution of 4-6 s. In Mongolian gerbils anesthetized with pentobarbital, the redox states of the nicotinamide adenine dinucleotide (NADH) and flavoprotein components of the electron transport chain exhibit two distinct phases during the wave of spreading depression: (1) a transient period of oxidation and (2) a prolonged period of reduction, during which the cytochromes are reduced, and the hemoglobin is predominantly in the deoxy form. These data are interpreted as indicating that the energy demand placed on the gerbil brain during such spreading depression wave is sufficient to drive the brain temporarily hypoxic.

Molecular mechanisms of gossypol action on sperm motility

1. Gossypol acetic acid inhibits collective motility of ejaculated ram spermatozoa. 2. Oxygen consumption was stimulated at low gossypol concentrations and inhibited as the concentrations are increased. 3. Gossypol inhibits respiration of permeabilized spermatozoa supported by durohydroquinome, which indicates a direct inhibition of mitochondrial electron transport chain. 4. The rapid reduction of mitochondrial dependent motility, high uncoupling effect and almost complete inhibition of mitochondrial calcium accumulation, indicate that gossypol inhibits motility in a mechanism by which mitochondrial uncoupling is involved.

Brain oxidative metabolism of the newborn dog: correlation between 31P NMR spectroscopy and pyridine nucleotide redox state

The effects of both anoxia and short- and long-term hypoxia on brain oxidative metabolism were studied in newborn dogs. Oxidative metabolism was evaluated by two independent measures: in vivo continuous monitoring of mitochondrial NADH redox state and energy stores as calculated from the phosphocreatine (PCr)/Pi levels measured by 31P nuclear magnetic resonance (NMR) spectroscopy. The hemodynamic response to low oxygen supply was further evaluated by measuring the changes in the reflected light intensity at 366 nm (the excitation wavelength for NADH). The animal underwent surgery and was prepared for monitoring of the two signals (NADH and PCr/Pi). It was then placed inside a Phosphoenergetics 260-80 NMR spectrometer magnet with a 31-cm bore. Each animal (1-21 days old) was exposed to short-term anoxia or hypoxia as well as to long-term hypoxia (1-2 h). The results can be summarized as follow: (a) In the normoxic brain, the ratio between PCr and Pi was greater than 1 (1.2-1.4), while under hypoxia or asphyxia a significant decrease that was correlated to the FiO2 levels was recorded. (b) A clear correlation was found between the decrease in PCr/Pi values and the increased NADH redox state developed under decreased O2 supply to the brain. (c) Exposing the animal to moderately long-term hypoxia led to a stabilized low-energy state of the brain with a good recovery after rebreathing normal air. (d) Under long-term and severe hypoxia, the microcirculatory autoregulatory mechanism was damaged and massive vasoconstriction was optically recorded simultaneously with a significant decrease in PCr/Pi values.(ABSTRACT TRUNCATED AT 250 WORDS)

Fiber optic surface fluorometry/reflectometry and 31-p-NMR for monitoring the intracellular energy state in vivo

Various members of the respiratory chain exhibit different optical properties in the reduced and oxidized forms, thus enabling the non-invasive monitoring of various organs in vitro as well as in vivo. Since the pioneering work of Chance, Cohen, Jobsis and Schoener in 1962, many groups of investigators adopted their approach in monitoring NADH oxidation reduction states in vivo for the brain as well as for other body organs. In 1972, we introduced flexible, optical fibers into the surface fluorometry replacing the usual "rigid" optical system used by other groups. During the last decade, this technique has been developed, improved and applied to many experimental setups in brain research and very recently was combined with 31P NMR spectroscopy for the puppy and the adult dog brain in vivo. In our system, the effects of movement artifacts and changes in blood oxygenation are negligible while the effects of tissue absorption or blood volume changes are considerable and could be minimized by subtraction of the reflectance signal from that of the fluorescence (1:1 ratio) providing the corrected fluorescence signal.

Effects of dibromochloropropane and ethylene dibromide on biochemical events and ultramorphology of ejaculated ram spermatozoa in vitro

The effects of dibromochloropropane (DBCP) and ethylene dibromide (EDB) on the function and ultrastructure of freshly ejaculated washed ram spermatozoa were assessed. These two compounds inhibited the collective motility of the sperm in a dose-dependent fashion when the sperm cells generated their energy either by mitochondrial respiration (2-deoxyglucose-treated sperm cells) or by the intact energy production system. DBCP and EDB inhibited the oxygen uptake by the sperm in a dose-dependent manner. No change in lactic acid accumulation and glucose utilization by the sperm cells was noted following DBCP and EDB addition. No change in the collective motility of the sperm was noted when DBCP or EDB were added to spermatozoa treated with the electron transfer inhibitor, antimycin A. Electron microscopy studies of sperm cells treated with DBCP revealed lesions in the plasma membrane adjacent to the acrosome and in the acrosomal membrane forming vesiculations. The inner membrane and the matrix space of the mitochondria were condensed following DBCP treatment, leaving a large mitochondrial peripheral space, compared with the control. EDB, at the concentration studied, caused no change in the ultramorphological structure of the sperm. DBCP was more potent, at least 4-fold, compared with EDB. An in vitro direct effect of DBCP and EDB on ram spermatozoa was established. It is suggested that quantitative measurements of sperm collective motility derived by different metabolic pathways can be used as an in vitro toxicological model for evaluation of toxicological and environmental factors affecting biological systems.

Three-dimensional metabolic mapping of the freeze-trapped brain: effects of ischemia in the Mongolian gerbil

The effects of unilateral carotid artery (left or right) occlusion on the three-dimensional metabolic mapping were studied in the Mongolian gerbil (Meriones unguiculatus). The brain was freeze-trapped by the liquid nitrogen funnel technique and was analyzed for the two-dimensional distribution of the reduced pyridine nucleotides and oxidized flavoprotein using a time-sharing micro-light guide surface fluorometer/reflectometer. The results could be summarized as follows. Bilateral carotid artery occlusion induced uniform effects in terms of redox state in the cerebral cortex and the olfactory bulbs. After unilateral carotid occlusion, the redox state of the ischemic ipsilateral hemisphere was higher and was not affected by blood volume changes as evaluated from the reflectance signal scanned in several brains. The narrow band of tissue near the midline of the ischemic hemisphere connected to the contralateral hemisphere blood supply appeared in a large number of gerbils. The anomaly in the redox state of the intracellular space also appeared in subcortical structures, as seen in all the two-dimensional mappings measured. It seems that blood circulation to the two olfactory bulbs is connected to the same blood vessel. It is suggested that unilateral carotid artery-occluded gerbils may show large variability inside the same hemisphere and therefore results must be evaluated very carefully.

Metabolic, ionic, and electrical responses of gerbil brain to ischemia

The effects of short- or long-term complete cerebral ischemia were studied in the gerbil brain using a multi-parameter monitoring system. Metabolic (NADH redox state) and hemodynamic responses were monitored by surface fluorometry-reflectometry. Ionic activities (K+ and pH) were measured by surface macroelectrodes. Electrical activity was evaluated by monitoring the general electrocorticogram (ECoG) as well as local DC steady potential (two sites). Two groups of gerbils were studied to compare the effects of 4-5 min occlusions with those of 30 min complete ischemia. During bilateral carotid artery occlusion the cortex is exposed to complete ischemia resulting in the complete depletion of O2 with attendant maximal reduction of NADH. Extracellular K+ began to increase as soon as energy reserves were decreased with a time course suggesting two different kinetic areas. Surface pH decreased very shortly after the occlusion. During the recovery phase, NADH was reoxidized soon after recirculation, whereas the pH and K+ recovery showed a short delay. ECoG did not recover even when all other parameters reached base-line levels. The recovery of all the measured parameters was correlated to the duration of the ischemic insult; i.e., the recovery from 30 min of ischemia took significantly longer than after 5 min of ischemia. We conclude that pH recovery depends on recirculation and adequate O2 supply to the tissue, whereas K+ recovery required not only an adequate O2 supply but also the integrity of the adenosine triphosphatase system.

The effect of testosterone on ram spermatozoa collective motility treated by antimycin A

The effect of testosterone on collective motility of antimycin A-treated, Ficoll-400-washed ejaculated ram spermatozoa was studied. The lowest concentration of antimycin A which blocked collective motility in hexose deprived cells (0.4 X 10(9) cells/ml) was 2 X 10(-7) M. Fructose, glucose and mannose, but not galactose, sorbitol or inositol, served as energy sources for collective motility. Cortisol, 5-beta-DHT, androsterone and 5-alpha-pregnan 3-beta-ol-20-one did not affect collective motility. Testosterone inhibited collective motility in a dose-dependent fashion. However, it did not affect lactic acid accumulation. The effect of testosterone was noted both on cells suspended in buffer containing fructose and on exogenously starved cells treated with fructose after collective motility arrest. It was concluded that testosterone might exert its inhibitory effect on motility by uncoupling fructolytic energy production to the tail motility system.

Brain NADH redox state monitored in vivo by fiber optic surface fluorometry

A new approach for the evaluation of brain energy metabolism in awake animals became possible as UV transmitting optical fibers became available. A variety of surface fiber optic fluorometers / reflectometers which were developed during the past decade enabled the monitoring of intramitochondrial NADH redox state in unanesthetized animals. The bundle of flexible fibers was connected to the brain via a cemented light guide holder implanted epidurally. The two signals obtained, 366 nm reflectance and 450 nm fluorescence, are subjected to various artifacts not connected to the intramitochondrial NADH redox state. In our system, the effects of movement artifacts and changes in blood oxygenation are negligible while the effects of tissue absorption or blood volume changes are considerable and could be minimized by subtraction of the two signals (1:1 ratio) providing the corrected fluorescence signal. The brain was exposed to various physiological and pathological conditions which resulted in the increase or decrease in the level of NADH. Under anoxia, hypoxia and ischemia, oxygen availability decreased and the metabolic state of the brain became more reduced (state 4-5 transition). When the brain was activated by seizures, spreading depression of hyperbaric oxygenation NADH became more oxidized (state 4-3 transition).

Brain metabolic responses to ischemia in the mongolian gerbil: in vivo and freeze trapped redox scanning

The interrelation between the metabolic responses to ischemia and seizure propensity was studied in two groups of seizure prone (SP) and non-seizure prone (NSP) gerbils. The metabolic state was evaluated in vivo using the light guide surface fluorometry as well as in the frozen brain scanned at liquid N2 temperature for Fp/PN ratio after monitoring the brain in vivo. The results could be summarized as follows. (1) Unilateral carotid artery occlusion led to partial ischemia in the ipsilateral hemisphere while the contralateral hemisphere remained normoxic. (2) Animal variability in the degree of the ischemia insult due to unilateral occlusion was not side dependent or in correlation with seizure propensity. (3) Significant correlation was found between the NADH increase during ischemia and the redox state measurements done in the same brain after funnel freezing with liquid nitrogen. (4) In a large number of the gerbils (not depending on the origin or strain) a peculiar inter-hemispheric blood supply connection was found. A narrow band (1 mm in width) of tissue near the midline obtained its blood via the same vessels supplying the contralateral hemisphere. (5) We did not find any correlation between blood vessel anatomy to the brain and seizure propensity.