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M Stupfel

Publications and source records attributed to M Stupfel.

At least 37 records · Page 2Linked to original sources
PubMed1983

Harmonic analysis of ultradian respiratory rhythms in four small laboratory vertebrates lit in LD12:12.

Fourier harmonic analysis has been applied to 20-min samples of VCO2, recorded every 12 sec over several (7-12) days, in one mouse, one rat, one guinea-pig, or one quail, maintained in controlled conditions of temperature, humidity and ventilation, and lit in LD12:12 (100 lux). The harmonic computations, during L and D of ultradian periods (1.2 hr less than tau less than 12 hr) evidence statistically significant differences in amplitude and phase between these four small laboratory species. These periodic respiratory differences correspond to discrepancies in their diurnal and nocturnal activities, and in their responses to light and dark.

Animals↗
PubMed1983

Inter and intraspecies genetic differences in survival to an acute carbon monoxide challenge in mice, rats, guinea-pigs, quails and chickens.

1. Groups of small laboratory vertebrates, of both sexes, have been submitted to an acute carbon monoxide challenge, close to a LD50. 2. An interspecific classification, from low to high CO sensitivity, gives: guinea-pigs-mice-chicks-rats-quails. 3. Interstrain statistical differences were observed in all species, with the exception of guinea-pigs. Furthermore, among two selected genotypes of Japanese quails, one was resistant to acute nitrogen hypoxia and to carbon monoxide intoxication and the other sensitive to both these types of hypoxia. 4. Interspecific comparisons show similarities of genetic differences to acute CO intoxication and acute nitrogen normobaric hypoxia.

Animals↗
PubMed1983

Environmental parameters in the experimental evaluation of a respiratory aggression.

Acute nitrogen normobaric hypoxic challenges, resulting in an approximately 50% overall survival, were performed in young adult male and female heterozygous OF1 mice under various environmental conditions. The time required to obtain 50% survival was 20 min for a constant pO2 of 42 Torr, and 151 min when pO2 was progressively lowered by nitrogen flushing from 159 to 16.5 Torr. In LD12:12 synchronized animals, survival was significantly (P less than 0.001) less when hypoxia was performed during the light (L) than during the dark (D) phase. Lowering the ambient temperature from 33.8 to 13.2 degrees C increased the length of the progressive hypoxia necessary to obtain a 50% survival of the mice by 1.7 times, and diminished the final pO2 from 35 to 12 Torr. Grouping and crowding both decreased hypoxic survival. A previous stress (starvation) diminished hypoxic resistance of mice, while a preceding hypoxia, carbon monoxide inhalation, or sodium cyanide injection had the opposite effect. In all instances, OF1 females were more resistant than males. Most of these variations can be related to differences in respiratory exchanges, locomotor activity and aggressiveness, which are dependent upon the various experimental environmental parameters.

Animals↗
PubMed1983

Evidence of genetic differences in acute hypoxia survival.

In a population of Japanese quail, a genetic selection was performed leading to two strains--one resistant and one susceptible to an acute hypoxic nitrogen challenge as well as to an acute carbon monoxide intoxication. Crossing these two strains gives an F1 hybrid whose survival to acute hypoxia appears to be very close to the susceptible strain. The difference in acute hypoxic survival already appears in embryos at the age of 12 d. Susceptibility to acute hypoxia seems to be a dominant character.

Animals↗
PubMed1982

Aging and intraspecific interactions in acute hypoxic survival of specific pathogen free OF1 mice of both sexes.

In light-synchronized pathogen-free OF1 mice, and LD50 acute hypoxic challenge was performed during the light period in which respiratory and motor activities are minimal. In males and females acute hypoxic resistance decreases with age. Grouping by ten significantly decreases hypoxic survival in young, adult, and senescent males, and in young females. In young mice, hypoxic survival is significantly less in males than in females, whether or not they have interindividual contacts. This sex-related difference disappears with aging in separated individuals, but remains in 230- and 420-day-old mice when there are interindividual contacts.

Aggression↗
PubMed1982

[Ultradian respiratory rhythms in groups of Sprague-Dawley rats of both sexes].

Spectral analysis of the carbon dioxide emitted in controlled environmental conditions (temperature: 20-21 degrees C; humidity: 50-60%; lighting: 150 lux in LD12-12; background noise: 70 dB), by groups of 14 month old Sprague Dawleys, shows ultradian respiratory rates with periods of a 107-72 minute range for males and 107-45 minute for females. Moreover, VCO2 related to body weight is higher in females than in males.

Animals↗
PubMed1982

Environmental pollution: the experimental and the human approach.

Thirty years have elapsed since laws preventing large scale pollution have begun to be made and enforced in industrial countries. Due partly to economic considerations, the actual methodology for the evaluation of health risks is now beginning to be considered. If the routine experimental and epidemiological investigations are complementary, their use, which needs respective delays of 4-5 and 20-30 years, is not adopted to determine the health effects of new chemicals or novel energies. To make up for these deficiencies, especially concerning the screening of carcinogenic and mutagenic potentials of chemicals, short in vitro tests have been developed, but they have not yet proved to be reliable. Among several investigational needs, the psychophysiological aspects of environmental pollution and the long-term effects of several kinds of nonionizing radiations, which more and more invade our environment, ought to be considered.

Environmental Pollutants↗
PubMed1980

Relation of sex and ageing to serotonin metabolism in rats.

The present study deals with serotonin (5-HT) metabolism at the central and peripheral levels in young, middle-aged and old male and female rats. From middle age, the level of endogenous 5-HT and the uptake of [14C] 5-HT were higher in the platelets of female rats than in those of male rats. By contrast, the retention of [14C] 5-HT by the platelets of male rats decreased after middle age. The 5-hydroxyindoleacetic acid (5-HIAA) level in plasma was lower in males than in females, and this level increased significantly with age in males. In brain, the tryptophan level decreased significantly with age in male rats, while the 5-HT level increased in males as well as females. The brain 5-HIAA level increased significantly with age in male rats. These results confirm that 5-HT metabolism is modified during the ageing process in rats, and that several factors may be involved in this modification.

Aging↗
PubMed1980

[Experimental study of the gassed lung].

The high degree of toxicity of gases released during fires leads to the use of an animal model min order to define a dose-effect relationship. The latter may be established taking into account the allometric laws of respiration in mammals. However, special anatomical features, sex, age and genetic factors must also be taken into consideration. Knowledge of the mechanism of acute intoxication enables an appropriate strategy of treatment ot ve selected. Nevertheless, the animal model is not fully adequate and it would appear to be necessary to also carry out epidemiological studies, which in particular will show the biological course of individuals who have survived severe intoxication. In this area, progress in respiratory and metabolic function studies will make it possible to considerably enlarge our possibilities of knowledge and, hence, of action.

Animals↗
PubMed1979

[Ultradian (between 5 and 70 minutes) respiratory (VO2, VCO2) rhythms of 4 small vertebrates used in biomedical research].

Four laboratory Vertebrate species with a predominant activity, either diurnal (Coturnix coturnix japonica), nocturnal (Rattus norvegicus, Mus musculus), or equivocal (Cavia porcellus), present, in usual housing conditions (temperature 20 degrees C, hygrometry 60-70%, acoustical background 70 dB, LD12:12 lighting L = 150 lx), food and water ad libitum, ultradian respiratory (VO2, VCO2) rhythms of short periods. The frequencies of these rhythms are independent of food intake and activity variations correlated to the lighting phase and regimen (LD, LL). The period (tau) of these ultradian respiratory rhythms is in isolated animals, between 5 and 70 min., according to the species studied. Grouping of several individuals of a same species, in a ventilated chamber, modifies the statistical distribution of the periods of the ultradian rhythms, but does not change the interspecies differences.

Animals↗
PubMed1979

Lifelong variations in heart rates in SPF Sprague Dawley rats of both sexes. Statistical correlations with body weights.

In unanesthetized Sprague Dawleys, SPF, of both sexes, housed in DL12:12 (100lux), at a temperature of 18--23 degrees C and a hygrometry of 60--75%, the measurements of heart frequencies during most part of their life point out a continuous decrease with age and an always higher (40--20 c.min-1) heart rate in females than in males. Significant correlations between heart rate and body weight can account for these heart rates variations. Between the ages of 72 and 589 days, which corresponds to the growth period, a linear relationship was established between Log heart rate (y; c. min-1) and Log body weight (x; gram); for males: Log y = 0.122 Log X +Log 938 and for females: Log y = -0.166 Log X + Log 1217. After the age of 600 days, which corresponds to senescence, decreases in heart rate as well as in body weight were observed in both sexes.

Age Factors↗
PubMed1979

Action of psychoactive drugs on sex-related differences of OF1 mice; intraspecific aggressiveness and acute hypoxia survival.

The purpose of this study was to examine (1) whether there were a relationship between the sex-related differences in 51-day-old OF1 mice, regarding male aggressiveness and their sensitivity to an acute hypoxic (nitrogen) 50% lethal challenge, and (2) whether these sex-related differences could be modified by psychoactive drugs acutely injected at nonincapacitating doses. The introduction of a previously isolated male in grouped (10) mice decreased survival to the hypoxic challenge more in females than in males. The previously isolated male, which acted as an 'aggressor' with grouped mice (fights and flights in male groups, and mounts in female groups), had a higher hypoxic mortality than the mice of the groups under aggression. Psychoactive drugs were intraperitoneally injected in grouped mice before the introduction of the male aggressor. Clorazepate (5 and 25 mg/kg) abolished the sex-related difference in hypoxic survival in groups in the presence of, but not in the absence of, the previously isolated male. Conversely, hydroxyzine (5 mg/kg) and dexamphetamine (1 mg/kg) suppressed the sex-related difference only in the absence of the aggressor. The effects of these drugs appeared to be associated more with flight than with fight reactions provoked by the introduction of the male aggressor. A deep hypothermia was noted in clorazepate-treated mice at the issue of the hypoxic challenge.

Aggression↗