Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ADAPTATION, PHYSIOLOGICAL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
PubMedDate not supplied

[Differential changes in serum levels of N-acetylneuramic acid and L-fucose as manifestations of physiological and physiopathological adaptation in man. Pregnancy as an experimental model. The tumoral, vascular and hepatic diseases as possible pathological models].

In this paper we report on the modifications that normal pregnancy introduces on the blood maternal serum concentrations of both N-acetyl maternal serum concentrations of both N-acetyl-neuraminic acid which is elevated above normal level and L-fucose which on the contrary is diminished. The experiences were performed with women in the last trimester of normal gestations. The probable physiochemical meaning and biological significance of those such changes are discussed in connection both to the maternal physiological adaptation during pregnancy and to the possible metabolical changes in intracellular regulation that might take place in such a situation. Similarly it is emphasized the probability that numerous pathological conditions including malignancy vascular diseases and hepatic disorders which course with overt changes in plasma glucoproteins might be amenable to present notorious modifications in N-acetylneuraminic acid and L-fucose plasmatic levels.

Adaptation, Physiological↗
PubMed2026

Polygenic Profiles Are Associated with Multidomain Biochemical Adaptations Across a Competitive Season in Professional Football Players: A Longitudinal Observational Study.

Background/Objectives: The physiological adaptations required to sustain elite football performance are influenced by both genetic background and dynamic biochemical responses, although their interaction across a full competitive season remains insufficiently characterized. This study aimed to examine the association between polygenic profiles and longitudinal biochemical adaptations in professional football players. Methods: Forty male professional football players competing in the Spanish league were monitored across two consecutive seasons. Blood samples were collected at six time points representing different phases of the competitive cycle. Biomarkers related to muscle metabolism, iron status, and hepatic function were analyzed. Polygenic profiles were calculated using Total Genotype Scores (TGS) for muscle performance, hepatic resilience, and metabolic efficiency. Associations were initially explored using Pearson correlations and subsequently evaluated using linear mixed-effects models accounting for repeated measurements within subjects. Results: Exploratory correlation analyses identified several associations between polygenic profiles and biochemical markers. Muscle performance TGS was inversely associated with serum iron (r = -0.36, p = 0.017) and positively associated with CK (r = 0.32, p = 0.041), Hb (r = 0.29, p = 0.046), and Hct (r = 0.33, p = 0.024). Hepatic resilience TGS showed inverse associations with ALT (r = -0.39, p = 0.012), urea (r = -0.51, p = 0.011), and BUN (r = -0.51, p = 0.011). Metabolic efficiency TGS was negatively associated with AST (r = -0.43, p = 0.044), ALT (r = -0.33, p = 0.025), and GGT across multiple time points (p = 0.001-0.013). However, although several nominal associations emerged in linear mixed-effects models accounting for repeated measurements, none remained statistically significant after false discovery rate correction. These findings should therefore be interpreted as exploratory and hypothesis-generating. Conclusions: Polygenic profiles may be associated with inter-individual variability in biochemical adaptations throughout a competitive season. These findings suggest the integration of genomic and biochemical data in precision athlete monitoring, while highlighting causal relationships and predictive applications require further investigation.

Humans↗
PubMed1993

Cardiac hypertrophy and failure--a disease of adaptation. Modifications in membrane proteins provide a molecular basis for arrhythmogenicity.

Cardiac hypertrophy is the physiological adaptation of the heart to chronic mechanical overload. Cardiac failure indicates the limits of the process. Cardiac hypertrophy is only one example of biological adaptation and results from the induction of several changes in gene expression, mostly of the fetal type, including those coding for the myosin heavy chain or the alpha-subunit of the Na+,K(+)-ATPase. From a thermodynamic point of view, the decrease in Vmax allows the heart to produce a normal tension at a lower cost. This process results from changes both in the sarcomere and in the expression of certain membrane proteins. The decrease in calcium transient is determined by several changes in membrane proteins that result in a rather fragile equilibrium in terms of calcium homeostasis. Any abnormal input in calcium will have exaggerated detrimental consequences on a hypertrophied myocyte and may cause automaticity and arrhythmias or an exaggerated response to anoxia in terms of compliance.

Adaptation, Physiological↗
PubMed2003

Atypical adaptive and cross-protective responses against peroxide killing in a bacterial plant pathogen, Agrobacterium tumefaciens.

Physiological adaptive and cross-protection responses to oxidants were investigated in Agrobacterium tumefaciens. Exposure of A. tumefaciens to sublethal concentrations of H2O2 induced adaptive protection to lethal concentrations of H2O2. Similar treatments with organic peroxide and menadione did not produce adaptive protection to subsequent exposure to lethal concentrations of these oxidants. Pretreatment of A. tumefaciens with an inducing concentration of menadione conferred cross-protection against H2O2, but not to tert-butyl hydroperoxide (tBOOH), killing. The menadione induced cross-protection to H2O2 was due to the compound's ability to highly induce the peroxide scavenging enzyme, catalase. The levels of catalase directly correlated with the bacterium's ability to survive H2O2 treatment. Some aspects of the oxidative stress response of A. tumefaciens differ from other bacteria, and these differences may be important in plant/microbe interactions.

Adaptation, Physiological↗
PubMed1992

[Chronic cardiac insufficiency, a disease of adaptation].

Cardiac hypertrophy due to a mechanical overload is not a disease per se but the physiological reaction of the heart to a disease which is usually arterial hypertension and/or coronary insufficiency. It results from the put into play of several changes in gene expression, frequently species-specific, which explain the thermodynamic improvement of the cardiac function and the physiological adaptation of the heart to the new environmental requirements. Some of these modifications can have detrimental consequences and explain the modifications of ventricular compliance and the high incidence of arrhythmias in ventricular hypertrophy. The most important changes in the genetic expression which have been reported so far after pressure overload are located on contractile proteins and on membrane proteins.

Adaptation, Physiological↗
PubMed1976

Aquatic life at high altitude: respiratory adaptations in the Lake Titicaca frog, Telmatobius culeus.

Telmatobius culeus has a combination of behavioral, morphological and physiological adaptations which allows an aquatic life in cool (10 degrees C) O2-saturated (at 100 mm Hg) waters at high altitude (3812 m). The skin surgace area is increased by pronounced folds and the cutaneous capillaries penetrate to the outer layers of the skin. The erythrocyte volume (394 mu3) is the smallest reported for amphibians. The P50 (15.6 at ph 7.65 and 10 degrees C) is the lowest, and the erythrocyte count (729 - 103/mm3) the highest for an anuran. The O2 capacity (11.7 vol%), hemoglobin (8.1 g/100 ml), hemoglobin concentration (0.281 pg/mu3) and hematocrit (27.9%) measured at 18 degrees C and 3800 m are all elevated in comparison with most amphibians. The O2 dissociation curve is sigmoid (n = 2), the Bohr factor is small (deltalog P50/deltapH = -0.30) and the buffering capacity (-8.9 m M HCO3 - 1-1) is typical for an aquatic amphibian. The metabolic rate (14.1 mul -g-1-h-u) is the lowest reported for a frog and among amphibians only the giant salamanders (Amphiuma, Necturus and Siren) have lower values. If prevent from surfacing in hypoxic waters, the frogs ventilate the skin by "bobbing" behavior; if allowed to surface, they will ventilate the small lungs and the metabolic rate increases to 23 mul-g-1-h-1.

Adaptation, Physiological↗
PubMed2006

Adaptation of healthy mastication to factors pertaining to the individual or to the food.

Mastication is a physiological process controlled by the central nervous system and modulated by inputs from the mouth. Both the intrinsic characteristics of the subject and the extrinsic characteristics of the chewed food are responsible for variations of the masticatory function. Age, gender and dental state constitute the most studied intrinsic factors whereas hardness, rheological characteristics such as plasticity or elasticity, and food size are the better known extrinsic factors. These factors cause physiological adaptations which can occur during individual cycles or the whole sequence of mastication. Electromyographic and jaw movements (kinematic) recordings are commonly used to study mastication, from which, several variables can be measured. Vertical and lateral amplitudes and, velocities of jaw movements, are only given by kinematic recordings. Bioelectrical activities per cycle or per sequence are closely linked to masticatory forces and are measured from electromyographic recordings. Number of cycles, sequence duration and masticatory frequency can be measured from both types of recordings. The objective of this review is to provide an overview of the variations of the measured masticatory variables that occur when mastication adapts to changes in characteristics of the individual or the food.

Adaptation, Physiological↗
PubMed2002

Prolonged unloading of rat soleus muscle causes distinct adaptations of the gene profile.

Using commercially available microarray technology, we investigated a series of transcriptional adaptations caused by atrophy of rat m. soleus due to 35 days of hindlimb suspension. We detected 395 out of 1,200 tested transcripts, which reflected 1%-5% of totally expressed genes. From various cellular functional pathways, we detected multiple genes that spanned a 200-fold range of gene expression levels. Statistical analysis combining L1 regression with the sign test based on the conservative Bonferroni correction identified 105 genes that underwent transcriptional adaptations with atrophy. Generally, expressional changes were discrete (<50%) and pointed in the same direction for genes belonging to the same cellular functional units. In particular, a distinct expressional adaptation of genes involved in fiber transformation; that is, metabolism, protein turnover, and cell regulation were noted and matched to corresponding transcriptional changes in nutrient trafficking. Expressional changes of extracellular proteases, and of genes involved in nerve-muscle interaction and excitation-contraction coupling identify previously not recognized adaptations that occur in atrophic m. soleus. Considerations related to technical and statistical aspects of the array approach for profiling the skeletal muscle genome and the impact of observed novel adaptations of the m. soleus transcriptome are put into perspective of the physiological adaptations occurring with muscular atrophy.

Adaptation, Physiological↗
PubMed2006

Study of physiological responses to acute carbon monoxide exposure with a human patient simulator.

Human patient simulators are widely used to train health professionals and students in a clinical setting, but they also can be used to enhance physiology education in a laboratory setting. Our course incorporates the human patient simulator for experiential learning in which undergraduate university juniors and seniors are instructed to design, conduct, and present (orally and in written form) their project testing physiological adaptation to an extreme environment. This article is a student report on the physiological response to acute carbon monoxide exposure in a simulated healthy adult male and a coal miner and represents how 1) human patient simulators can be used in a nonclinical way for experiential hypothesis testing; 2) students can transition from traditional textbook learning to practical application of their knowledge; and 3) student-initiated group investigation drives critical thought. While the course instructors remain available for consultation throughout the project, the relatively unstructured framework of the assignment drives the students to create an experiment independently, troubleshoot problems, and interpret the results. The only stipulation of the project is that the students must generate an experiment that is physiologically realistic and that requires them to search out and incorporate appropriate data from primary scientific literature. In this context, the human patient simulator is a viable educational tool for teaching integrative physiology in a laboratory environment by bridging textual information with experiential investigation.

Adaptation, Physiological↗
PubMed2006

Influence of fluctuating salinity on insecticide tolerance of two euryhaline arthropods.

Among many other abiotic variations in an estuarine ecosystem, osmotic stress is an inescapable part of life. Organisms living in such environments must cope with changing osmotic conditions by either behavioral or physiological adaptations. Pollutants may increase the physiological stresses that an osmoregulating animal may encounter. We have developed a flow-through system that exposes test species to insecticides and continuously changing salinity conditions. This system has provided an insight into how susceptibility of a species to an insecticide can be affected by changing concentrations of salinity. Toxicity tests using this system were conducted with two arthropod species that are found in saline habitats: mosquito Aedes taeniorhynchus (Wiedemann) and brine shrimp (Artemia sp.). Four insecticides-aldicarb, dimethoate, imidacloprid, and tebufenozide-were studied. Both species were exposed for 48 h to a concentration of various insecticides that would cause 50% of the population to die in hyperosmotic artificial sea water (ASW). The mortality rate for both species was more acute in increasing salinity (10-200% ASW) than in decreasing salinity (200-10% ASW) conditions. A. taeniorhynchus was more susceptible than Artemia when exposed to its hyperosmotic LC50 concentration of toxicant while experiencing a change in salinity, e.g., adjusting to a changing salinity decreased the LT50. Our results indicated a change in salinity; more importantly, the direction of change altered the susceptibility of these organisms.

Aedes↗
PubMed1992

Cardiovascular physiology. Effects of microgravity.

Experiments during spaceflight and its groundbase analog, bedrest, provide consistent data which demonstrate that numerous changes in cardiovascular function occur as part of the physiological adaptation process to the microgravity environment. These include elevated heart rate and venous compliance, lowered blood volume, central venous pressure and stroke volume, and attenuated autonomic reflex functions. Although most of these adaptations are not functionally apparent during microgravity exposure, they manifest themselves during the return to the gravitational challenge of earth's terrestrial environment as orthostatic hypotension and instability, a condition which could compromise safety, health and productivity. Development and application of effective and efficient countermeasures such as saline "loading," intermittent venous pooling, pharmacological treatments, and exercise have become primary emphases of the space life sciences research effort with only limited success. Successful development of countermeasures will require knowledge of the physiological mechanisms underlying cardiovascular adaptation to microgravity which can be obtained only through controlled, parallel groundbased research to complement carefully designed flight experiments. Continued research will provide benefits for both space and clinical applications as well as enhance the basic understanding of cardiovascular homeostasis in humans.

Adaptation, Physiological↗
PubMed2006

Cold stress tolerance of Listeria monocytogenes: A review of molecular adaptive mechanisms and food safety implications.

The foodborne pathogen Listeria monocytogenes has many physiological adaptations that enable survival under a wide range of environmental conditions. The microbes overcome various types of stress, including the cold stress associated with low temperatures in food-production and storage environments. Cold stress adaptation mechanisms are therefore an important attribute of L. monocytogenes, enabling these food pathogens to survive and proliferate to reach minimal infectious levels on refrigerated foods. This phenomenon is a function of many molecular adaptation mechanisms. Therefore, an improved understanding of how cold stress is sensed and adaptation measures implemented by L. monocytogenes may facilitate the development of better ways of controlling these pathogens in food and related environments. Research over the past few years has highlighted some of the molecular aspects of cellular mechanisms behind cold stress adaptation in L. monocytogenes. This review provides an overview of the molecular and physiological constraints of cold stress and discusses the various cellular cold stress response mechanisms in L. monocytogenes, as well as their implications for food safety.

Adaptation, Physiological↗
PubMed2004

Prenatal programming of adult thyroid function by alcohol and thyroid hormones.

Increasing evidence associates environmental challenges early in life with permanent alterations of physiological functions in adulthood. These changes in fetal environment can trigger physiological adaptations by the fetus, called fetal programming, which may be beneficial before birth but permanently influence the physiology of the organism. In this study, we investigated the potential connection between alcohol-induced decreased maternal thyroid function and the hypothalamic-pituitary-thyroid (HPT) function of adult rat offspring. Plasma 3,5,3'-triiodothyronine (T(3)), thyroxine (T(4)), and thyroid-stimulating hormone (TSH) levels were decreased in alcohol-consuming (E) dams on gestational day 21 compared with ad libitum- (C) and pair-fed (PF) controls. No significant differences were found in HPT function in young offspring (3 wk of age) between diet groups. However, adult fetal alcohol-exposed (FAE) offspring had significantly decreased levels of T(3) along with elevated TSH compared with control offspring. T(4) administration to the mother did not normalize the hypothyroid state of the adult FAE offspring. Interestingly, administration of T(4) to control pregnant dams decreased plasma T(3) of the adult female offspring only, whereas T(4) together with maternal alcohol consumption or pair-feeding led to decreased TSH and T(4) in the adult female offspring. Our results suggest that ethanol consumption and T(4) administration alter maternal HPT function, leading to prenatally programmed permanent alterations in the thyroid function of the adult offspring.

Adaptation, Physiological↗
PubMed2001

Selective adaptation to noxious foods by a herbivorous insect.

When animals repeatedly sample a noxious food over a period of 1-4 days, they can markedly reduce their aversive behavioral response to the diet's unpleasant taste (e.g. 'bitterness') or toxic effects. This long-term adaptation process is selective, however, permitting insects to adapt physiologically to some but not all noxious foods. We hypothesized (i) that the selective nature of this adaptation process stems from the fact that some unpalatable foods are toxic while others are harmless and (ii) that insects have more difficulty adapting to foods that are both unpalatable and toxic. Our model system consisted of Manduca sexta caterpillars and two compounds that taste bitter to humans and elicit an aversive behavioral response in this insect (salicin and aristolochic acid). We found that 2 days of exposure to a salicin diet completely adapted the aversive response of the caterpillars to salicin, but that exposure to an aristolochic acid diet failed to adapt the aversive response to aristolochic acid. We determined that M. sexta could not adapt to the aristolochic acid diet because it lacked mechanisms for reducing the compound's toxicity. In contrast, the salicin diet did not produce any apparent toxic effects, and the caterpillars adapted to its aversive taste within 12 h of exposure. We also found that the salicin adaptation phenomenon (i) was mediated by the central gustatory system, (ii) generalized to salicin concentrations that were twice those in the adapting diet and (iii) offset spontaneously when the caterpillar was transferred to a salicin-free diet. We propose that toxicity is a more significant barrier to dietary adaptation than 'bitterness' in this insect.

Adaptation, Physiological↗
PubMed2005

The psychobiology of emotion: the role of the oxytocinergic system.

A necessary condition for the individual's survival is the capacity for mental, behavioral, and physiological adaptation to external and internal conditions. Consequently, the integrated organism strives to maintain a dynamic, functional balance and integrity under varying conditions. Effective individual adaptation processes are basically dependent on the functioning of the integrated psychophysiological system. In humans, the brain plays a fundamental role in these processes. It serves the adaptation of individuals to current and anticipated conditions by selecting, interpreting, and transforming information into mental, behavioral, and physiological responses. In doing so, the incoming information is linked to existing structures of emotions, values, and goals. Consequently, the interpretation of external information may vary and become subjective depending on an individual's present and past experiences (see e.g., Magnusson, 2003). Hitherto, empirical research has been mainly concerned with the aspect of the psychophysiological system, which is activated in situations that are perceived by the individual as threatening, harmful, or demanding and in which the fight-flight and stress responses described by Cannon (1929) and Selye (1976) play an important role. The aim of this article is to draw attention to a component of the psychophysiological system, the calm and connection system, underlying well-being and socialization. By including this new system, the model of the integrated individual becomes more complete and it enriches the understanding of emotional aspects of brain functioning.

Adaptation, Physiological↗
PubMed2026

Adaptations to breath-hold diving: from traditional divers to elite athletes.

Breath-hold diving exposes humans to repeated episodes of profound hypoxia and hypercapnia, eliciting physiological adaptations that enable prolonged underwater performance. This article summarises current knowledge on chronic adaptations in elite breath-hold athletes and traditional diving populations, including the Bajau sea nomads of Southeast Asia and the Korean Haenyeo divers. Evidence indicates that repeated apnoea induces adaptations across multiple physiological systems. Haematological changes include increased spleen size and enhanced splenic contraction, augmenting circulating haemoglobin and oxygen stores during apnoea. In elite divers, structured training can increase resting spleen volume, whereas the Bajau exhibit genetically associated splenic enlargement linked to variants near the PDE10A gene. Cardiopulmonary adaptations include modified pulmonary vascular responses to hypoxia, improved oxygen conservation, and metabolic shifts favoring efficient mitochondrial energy production. Molecular adaptations involve enhanced antioxidant defenses and activation of hypoxia-responsive pathways that may mitigate oxidative stress associated with repeated hypoxia-reoxygenation cycles. Emerging evidence also suggests neural plasticity and possible structural brain adaptations, although the long-term neurological consequences of chronic intermittent hypoxia exposure remain uncertain. Studies of traditional diving populations indicate that both phenotypic plasticity and genetic selection contribute to diving capacity, highlighting interactions between training and evolution. Despite these benefits, breath-hold diving also carries risks, including hypoxic blackout, decompression sickness, and potential neurological injury. Understanding the mechanisms underlying human tolerance to extreme hypoxia may have implications beyond diving physiology, including applications in cardiovascular medicine, hypoxic diseases, and rehabilitation. Further longitudinal, genomic, and mechanistic studies are needed to clarify the limits, benefits, and clinical relevance of these adaptations.

Humans↗
PubMed1985

Naltrexone antagonizes the biobehavioral adaptation to cold water stress in rats.

The reported studies on the development of tolerance to the analgesic effects of stress have been mostly concerned with the involvement of opioid or non-opioid substances in stress-induced analgesia (SIA). To further investigate the processes involved in SIA tolerance, rats were exposed to forced intermittent cold water swim (ICWS, 18 exposures, 3/min, 10 sec each) on 16 consecutive days. On days 15 and 16, they were injected prior to swim with saline and naltrexone (10 mg/kg), respectively. During swim, three types of readily identifiable behaviors were observed. They may be characterized by immobility and horizontal floating (Type I), intensive activity and escape attempts (Type II), and passivity and "behavioral despair" (Type III). In the acute condition, only Type II and Type III appear in sequence. In the chronic condition, the sequence of behaviors is: Type I, Type II, and Type III. Thirty minutes after swim, analgesia, core temperature, and degree of inactivity were measured. With chronic exposure, tolerance developed to the analgesia, core hypothermia and hypoactivity induced by the ICWS. Type I behavior appeared on day 3 or 4 and persisted throughout the chronic treatment. Type II behavior did not adapt. Naltrexone (10 mg/kg) antagonized the adaptive aspect of all those variables where adaptation or tolerance were found (analgesia, hypoactivity, core hypothermia, and Type I behavior) but had no effect on Type II behavior where no adaptation was observed. It is suggested that the endorphins have a functional role in the behavioral and and physiological adaptation to aversive stressful environmental situations.

Adaptation, Physiological↗
PubMed1997

[Pregnancy and sports--physiologic considerations and practical examples].

Mothers-to-be expect practical and competent consulting from their obstetricians rather than orders or interdictions regarding their way of living. Particularly answering questions concerning physical activity and sports during pregnancy require profound knowledge on the physiological adaptations of the cardiopulmonary system and the anatomical structures and-on the other hand-on performance and sports' physiology. Resuming these alterations through pregnancy there result practical examples and proposals of physical activities in gestation as therapeutic and preventive measures. Moreover risks and contraindications are worked out.

Adaptation, Physiological↗