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PubMed1992

Spatial-frequency-contingent color aftereffects: adaptation with one-dimensional stimuli.

The McCollough effect was shown to be spatial-frequency selective by Lovegrove and Over (1972) after adaptation with vertical colored square-wave gratings separated by 1 octave. Adaptation with slide-presented red and green vertical square-wave gratings separated by 1 octave failed to produce contingent color aftereffects (CAEs). However, when each of these gratings was adapted alone, strong CAEs were produced. Adaptation with vertical colored sine-wave gratings separated by 1 octave also failed to produce CAEs, but strong effects were produced by adaptation with each grating alone. By varying the spatial frequency of the test sine wave, CAEs were found to be tuned for spatial frequency at 2.85 octaves after adaptation of 4 cycles per degree (cpd) and at 2.30 octaves after adaptation of 8 cpd. Adaptation of both vertical and horizontal sine-wave gratings produced strong CAEs, with bandwidths ranging from 1.96 to 2.90 octaves and with lower adapting contrast producing weaker CAEs. These results indicate that the McCollough effect is more broadly tuned for spatial frequency than are simple adaptation effects.

Adaptation, Ocular↗
PubMed1990

[A study of factors influencing the state of adaptation of hemiplegic patients].

The purposes of this study are to delineate a profile of the state of a stroke patient's adaptation at 3 months after hospitalization and to explore the relationship between the level of adaptation and the variables which influence the adaptation of hemiplegic patients. To these ends, theoretical framework was derived basically from the stress adaptation model. The basic assumption underlying the level of adaptation is influenced by the presenting focal, contextual and residual stimuli. This group of stimuli is further operationalized and represented by a perception of stress, which is the perceived effect of the disability and by the mediating variables such as sociodemographic factors as an external conditioning variables and perceived social support and hardiness personality characteristics as an internal intervening variables. The dependent variables in this study is the level of physical, psychological and social adaptation and is hypothesized to be a function of the interaction between 3 sets of variables namely, the perceived disability effect, external conditioning variables and internal intervening variables. A total of fourty three subjects from 3 general hospitals in Seoul were observed and interviewed with the aid of 7 structured instruments. The data were collected twice on each subject: first, at the pre-discharge period and at 3 months post-discharge from hospital for the second time. The study was carried out for the period from February to August, 1988. The instruments used for the study include 4 existing scales and 3 scales developed by the researcher for this study. They are: 1) The ADL dependency scale and the scale of the clinical physical functions for the assessment of physical adaptation. 2) the SDS (self report of depression) to measure the level of psychological adaptation. 3) The scale for the amount of social activities for the measurement of the level of social adaptation. 4) The scale for the perceived effect of disability for the measurement of the focal stimuli. 5) The health related hardiness scale and the perceived interpersonal support self evaluation list (ISEL) for the measurement of the hardiness personality character and the perceived social support. The data obtained were analyzed using percentage, one way ANOVA, Pearson coefficients correlation and stepwise multiple regression. The findings provide valuable information about the present level of physical adaptation at 3 months after discharge. The patient revealed a decreased ADL dependency and lowered limitation of physical function as compared with pre-discharge state. Psychologically, the average degree of depression at follow up was within normal range of depression.(ABSTRACT TRUNCATED AT 400 WORDS)

Activities of Daily Living↗
PubMed1998

The antiarrhythmic effect of adaptation to intermittent hypoxia.

There was shown an antiarrhythmic effect of adaptation to intermittent hypobaric hypoxia in ischemia, reperfusion, experimental infarction and postinfarction cardiosclerosis (F.Z. Meerson, 1988). These results was obtained in whole animal experiments. In our study it was demonstrated that the antiarrhythmic effect of adaptation to hypoxia persisted in hearts after isolation, in absence of the effect of neural and humoral factors on the organ. Adaptation of animals to intermittent hypoxia was produced by "stepwise" elevations in an altitude chamber: first day--1000 m; second day--2000 m; third day--3000 m and rest of the days--to 4000 m above sea level. The course of doses adaptation to hypoxia lasted for 40 days; each daily exposure lasted 5 hours. The analysis of arrythmogenic and contractural effects of hypercalcium perfusion and "calcium paradox" phenomenon shows a significant decrease of these effects in hearts of adapted animal. The bioelectrical activity investigation of papillary muscles cardiomyocytes, obtained from hearts of adapted animals, was shown, in hypercalcium perfusion condition, a complex of antiarrhythmogenic changes which was expressed in limitation of rest and action potentials decreasing and in maintenance of the action potential duration. In papillary muscles, obtained from adapted animals, the contracture and the depression of contractility was also smaller. In experiments on resting papillary muscles we found that adaptation to intermittent hypoxia significantly decreased contractural and depolarizing effects of low-sodium perfusion. Thus adaptation to intermittent hypobaric hypoxia resulted, at cardiomyocytes level, in a complex of antiarrhythmic changes which may indicate a protective effect of this kind of adaptation in cardiac arrhythmias.

Adaptation, Physiological↗
PubMed1998

[Adaptive response of CHL to hydrogen peroxide induced oxidative stress and the mechanism].

OBJECTIVE: To study peroxidative adaptive response of eukaryocyte and its mechanisms. METHODS: Chinese hamster fibroblast cells (CHL) pretreated with low concentration of hydrogenperoxide (H2O2) were retreated by the following high concentration of H2O2. Cellular viability (MTT method) and DNA strand break (FADU method), as adaptive-acting indicators were selected. Meanwhile, CAT activity and PARP were separately determined on the adaptive response to DNA strand break. RESULTS: There were peroxidative adaptive responses to non-lethal damage of high concentration H2O2 in both cellular viability and DNA strand break levels; but adaptive models (conditions) between the two levels were different. The CAT activity induced by the low level of H2O2 was enhanced and related to peroxidative adaptation to DNA break. Furthermore, PARP blocker, 3-AB, markedly inhibited the adaptive response to DNA-strand break. CONCLUSION: Two models adaptation may be via different inducible adaptive pathways. CAT and PARP participated in the induction of peroxidative adaptation to DNA strand break.

Adaptation, Physiological↗
PubMed2001

Contrast adaptation in human retina and cortex.

PURPOSE: Although cortical contrast adaptation has been extensively studied with both psychophysical and electrophysiological techniques, little is known about retinal contrast adaptation in humans. METHODS: Retinal and cortical long-term contrast adaptation was assessed with simultaneous measurement of pattern electroretinogram (PERG) and cortical visual evoked potentials (VEPs). This study involved three approaches: sampling of the contrast transfer function from 2.7% to 98% with adaptation to high (98%) and low (7.3%) contrasts, linearity of adaptation effects, and transfer of contrast adaptation between parallel and orthogonal grating orientations. RESULTS: Contrast adaptation affected retinal and cortical recordings quite differently. The VEP showed a sigmoid contrast transfer function, which was shifted toward higher contrasts (by a factor of 1.9), whereas amplitudes at higher test contrasts were enhanced to 127%. The PERG decreased in amplitude to approximately 90%, and the latency was significantly reduced by 4 to 6 msec (P < 0.05). All measured effects were linear with adaptation contrast. Orientation played no role in the PERG results, whereas the VEP was enhanced to 125% when tested parallel and to 150% when tested orthogonal to adaptation. CONCLUSIONS: VEP results confirm and extend previous findings and fit well with single-cell recordings. The PERG findings suggest that retinal contrast adaptation occurs and mainly operates in the temporal domain, comparable to rapid gain-control findings in cats and primates.

Adaptation, Ocular↗
PubMed2003

Short-term adaptation of the VOR: non-retinal-slip error signals and saccade substitution.

We studied short-term (30 min) adaptation of the vestibulo-ocular reflex (VOR) in five normal humans using a "position error" stimulus without retinal image motion. Both before and after adaptation a velocity gain (peak slow-phase eye velocity/peak head velocity) and a position gain (total eye movement during chair rotation/amplitude of chair motion) were measured in darkness using search coils. The vestibular stimulus was a brief ( approximately 700 ms), 15 degrees chair rotation in darkness (peak velocity 43 degrees /s). To elicit adaptation, a straight-ahead fixation target disappeared during chair movement and when the chair stopped the target reappeared at a new location in front of the subject for gain-decrease (x0) adaptation, or 10 degrees opposite to chair motion for gain-increase (x1.67) adaptation. This position-error stimulus was effective at inducing VOR adaptation, though for gain-increase adaptation the primary strategy was to substitute augmenting saccades during rotation while for gain-decrease adaptation both corrective saccades and a decrease in slow-phase velocity occurred. Finally, the presence of the position-error signal alone, at the end of head rotation, without any attempt to fix upon it, was not sufficient to induce adaptation. Adaptation did occur, however, if the subject did make a saccade to the target after head rotation, or even if the subject paid attention to the new location of the target without actually looking at it.

Adaptation, Physiological↗
PubMed2006

Plasticity of physiology in Lobelia: testing for adaptation and constraint.

Phenotypic plasticity is thought to be a major mechanism allowing sessile organisms such as plants to adapt to environmental heterogeneity. However, the adaptive value of many common plastic responses has not been tested by linking these responses to fitness. Even when plasticity is adaptive, costs of plasticity, such as the energy necessary to maintain regulatory pathways for plastic responses, may constrain its evolution. We used a greenhouse experiment to test whether plastic physiological responses to soil water availability (wet vs. dry conditions) were adaptive and/or costly in the congeneric wildflowers Lobelia cardinalis and L. siphilitica. Eight physiological traits related to carbon and water uptake were measured. Specific leaf area (SLA), photosynthetic rate (A), stomatal conductance (gs), and photosynthetic capacity (Amax) responded plastically to soil water availability in L. cardinalis. Plasticity in Amax was maladaptive, plasticity in A and g(s) was adaptive, and plasticity in SLA was adaptively neutral. The nature of adaptive plasticity in L. cardinalis, however, differed from previous studies. Lobelia cardinalis plants with more conservative water use, characterized by lower g(s), did not have higher fitness under drought conditions. Instead, well-watered L. cardinalis that had higher g(s) had higher fitness. Only Amax responded plastically to drought in L. siphilitica, and this response was adaptively neutral. We detected no costs of plasticity for any physiological trait in either L. cardinalis or L. siphilitica, suggesting that the evolution of plasticity in these traits would not be constrained by costs. Physiological responses to drought in plants are presumed to be adaptive, but our data suggest that much of this plasticity can be adaptively neutral or maladaptive.

Acclimatization↗
PubMed1989

[The partial recA-lexA dependence of the adaptive response of Escherichia coli to exposure to methylmethane sulfonate].

A study was made of the adaptive response to methylmethane sulfonate (MMS) in E. coli. (18 strains of B, WP2, and H/r30 groups, including three strains of bacteria with pKM101 plasmid). The adaptation of wild type cells and uvrA- and uvrB- mutants to non-lethal concentrations of MMS (10-30 mkg/ml during 90-120 min) leads to a significant increase in their resistance to lethal MMS concentrations (10-30 mM for 10-120 min): the dose modifying factor (DMF) being 1.5-1.8. In single recA or lexA mutants (or double recA uvr- and lexA uvr- mutants) the efficiency of adaptive response to MMS was significantly lower: the DMF being 1.1-1.2. In Bs-1 gamma R strain with intragenic suppressor of lexA gene the adaptive response efficiency was the same as in B/r (recA+lexA+) strain. There is no adaptive response to MMS in polA- strains. The adaptive response to MMS in E. coli is different from that to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and N-methylnitrosourea (MNM), because in these two cases it is absolutely lexA-recA dependent. It is supposed that a partial recA-lexA dependence of the adaptive response to MMS in E. coli may be due to a specific MMS-induced lethal damage that induces an adaptive repair non-related to the system of recA-lexA-independent adaptive responses to MNNG and MNM. The presence of a plasmid of drug resistance pKM101 exerts no influence on the value, efficiency and recA-lexA-dependence of the adaptive response of E. coli to MMS.

Adaptation, Physiological↗
PubMed1989

Adaptation to telescopic spectacles: vestibulo-ocular reflex plasticity.

The vestibulo-ocular reflex (VOR) is a mechanism for the production of rapid compensatory eye movements during head movements. To investigate the adaptation of this reflex to spectacle magnifiers, the effect on the VOR of a brief period of wearing telescopic spectacles during head rotation was studied in normal subjects. VOR gain, as measured in darkness, was defined to be the ratio of compensatory slow phase eye velocity to head velocity. Initial VOR gain as measured for vertical axis sinusoidal head rotation at 0.1 Hz, amplitude 60 degrees/sec, was about 0.7. After 15 min adaptation by sinusoidal rotation during the viewing of a remote video display through X2, X4, or X6 binocular telescopic spectacles, 47-70% of subjects exhibited significant VOR gain increases of 7-46%. These increases were measured with occlusion of the unmagnified visual field peripheral to the telescopes during adaptation. There was considerable interindividual variability in adaptation to telescopic spectacles. Telescopic spectacle power had little or no effect on the amount of VOR change after adaptation, although all telescope powers produced a greater VOR gain change than did adaptation without telescopes. Testing of VOR gain at multiple frequencies indicated that adaptation to telescopic spectacles by rotation at a single sinusoidal frequency induces VOR gain changes across a broad spectrum of frequencies of head rotation. When the unmagnified peripheral visual field was unobstructed during adaptation, VOR gain increases were significantly less than when the unmagnified peripheral visual field was occluded, and were similar to those observed during adaptation without the wearing of telescopic spectacles at all. VOR gain adaptation was associated with amerlioration of symptoms of oscillopsia and motion discomfort initially experienced by about 20% of subjects wearing telescopic spectacles.

Adaptation, Physiological↗
PubMed1984

[Myocardial contraction in the reverse development of adaptation to short-term exposure to stress].

Contractile function of an isolated right atrium was studied in short-term stressor effects-adapted male Wistar rats at different times after adaptation was completed. Adaptation to short-term stressor effects was shown to produce a restricted decrease of myocardial contractility shortly after adaptation was completed. At the 3d day another decrease of contractile function was noted. However, contractile function returned to the control level by the 5th day. At the same time adaptation completely prevented the impairment of myocardial contractility, induced by prolonged stress. The protective effect was seen immediately after adaptation, by days 3 and 5 after it, being reduced by day 10. It is assumed that at the 5th day after adaptation, the animals experience the post-adaptation state marked by disappearance of the negative adaptation effect and by remarkable protective effect of adaptation. As a result, all the characteristics of myocardial contractility evaluated after prolonged stress experienced by the animals at the 5th day following short-term stressor effects do not differ from control parameters.

Adaptation, Physiological↗
PubMedDate not supplied

The role of ITP-DAG regulatory cascade in the mechanism of cardioprotective effect of adaptation to stress.

OBJECTIVE: To study the role of inositol-triphosphate-diacylglycerol (ITP-DAG) regulatory cascade in the development of adaptive stabilization of structures. DESIGN: Double-blind, randomized trial. ANIMALS: Wistar male rats, 250 to 300 g. INTERVENTIONS: Adaptation to restrained stress. Investigation of adapted animals consisted of three main steps: first, alpha 1-adrenoreactivity of isolated heart from animals adapted to short term stress exposure were studied. Second, the state of a1-adrenoceptors and phospholipase C activity were estimated by biochemical methods. Third, the contractile function of heart and its in vivo resistance to acute anoxia were studied as well as the resistance of isolated heart to ischemia reperfusion injury. All these studies were performed 15 and 30 days following the onset of adaptation to immobilization stress. MAIN RESULTS: It is known that in adaptation to repeated stress exposure, a phenomenon of adaptive stabilization of structures (PhASS) develops. This phenomenon manifests itself, in particular, in isolated hearts from adapted animals as well as nuclei and cytoplasmic organelles of cardiomyocytes that acquire quite a high resistance to a broad spectrum of damaging factors. The present study shows that the development of PhASS and its cardioprotective effects with respect to anoxia, ischemia and reperfusion are associated with an increase in positive inotropic effect of selective alpha-agonist phenylephrine and an activation of myocardial phospholipase C. In long term adaptation both these alterations disappear and the PhASS-induced cardioprotective effect disappears simultaneously. A hypothesis on the important role of ITP-DAG regulatory cascade in PhASS development is put forward. CONCLUSION: ITP-DAG regulatory cascade plays an important role in the mechanism of cardioprotective effect of adaptation to repeated stress exposure, in particular in increased resistance of the heart to ischemia and subsequent reperfusion.

Adaptation, Physiological↗
PubMed1981

Dietary regulation of pancreatic protein synthesis. II. Kinetics of adaptation of protein synthesis and its effect on enzyme content.

The kinetics of the adaptative changes in the relative rates of synthesis and pancreatic concentrations of amylase, chymotrypsinogen and trypsinogen were studied over 10 days of adaptation to a carbohydrate-rich (G), or a protein-rich (P) diet. During adaptation to the P diet, 60% of the adaptative decrease of the amylase to chymotrypsinogen ratio of incorporation was complete within 24 h of feeding and plateau values were obtained after five days. Adaptation to the G diet was only 20% complete after 24 h and plateau values were obtained later than with the P diet. The evolution of the ratio of concentrations of amylase and chymotrypsinogen followed those of incorporation in the adaptation to both diets. These results support the determinant role of adaptative changes in the rates of synthesis of individual enzymes on the dietary adaptation of enzyme proportions in the pancreas. The differences in the kinetics of adaptation to the two diets suggest that different mechanisms are involved in the adaptative regulation of protein synthesis to a carbohydrate-rich diet or a protein-rich diet.

Amylases↗
PubMed1989

Photocycles of bacteriorhodopsin in light- and dark-adapted purple membrane studied by time-resolved absorption spectroscopy.

Nanosecond time-resolved absorption spectra have been measured throughout the photocycle of bacteriorhodopsin in both light-adapted and dark-adapted purple membrane (PM). The data from dark-adapted samples are interpretable as the superposition of two photocycles arising independently from the all-trans and 13-cis retinal isomers that coexist in the dark-adapted state. The presence of a photocycle in dark-adapted PM which is indistinguishable from that observed for light-adapted PM under the same experimental conditions is demonstrated by the observation of the same five relaxation rates associated with essentially identical changes in the photoproduct spectra. This cycle is attributed to the all-trans component. The cycle of the 13-cis component is revealed by scaling the data measured for the light-adapted sample and subtracting it from the data on the dark-adapted mixture. At times less than 1 ms, the resulting difference spectra are nearly time-independent. The peak of the difference spectrum is near 600 nm, although there appears to be a slight (approximately 2 nm) blue-shift in the first few microseconds. Subsequently the amplitude of this spectrum decays and the peak of the difference spectrum shifts in two relaxations. Most of the amplitude of the photoproduct difference spectrum (approximately 80%) decays in a single relaxation having a time constant of approximately 35 ms. The difference spectrum remaining after this relaxation peaks at approximately 590 nm and is indistinguishable from the classical light-dark difference spectrum, which we find, in experiments performed on a much longer time scale, to peak at 588 nm. The decay of this remaining photo-product is not resolvable in the nanosecond kinetic experiments, but dark adaptation of a completely light-adapted sample is found to occur exponentially with a relaxation time of approximately 2,000 s under the conditions of our experiments.

Bacteriorhodopsins↗
PubMed2002

Adaptive sampling in research on risk-related behaviors.

This article introduces adaptive sampling designs to substance use researchers. Adaptive sampling is particularly useful when the population of interest is rare, unevenly distributed, hidden, or hard to reach. Examples of such populations are injection drug users, individuals at high risk for HIV/AIDS, and young adolescents who are nicotine dependent. In conventional sampling, the sampling design is based entirely on a priori information, and is fixed before the study begins. By contrast, in adaptive sampling, the sampling design adapts based on observations made during the survey; for example, drug users may be asked to refer other drug users to the researcher. In the present article several adaptive sampling designs are discussed. Link-tracing designs such as snowball sampling, random walk methods, and network sampling are described, along with adaptive allocation and adaptive cluster sampling. It is stressed that special estimation procedures taking the sampling design into account are needed when adaptive sampling has been used. These procedures yield estimates that are considerably better than conventional estimates. For rare and clustered populations adaptive designs can give substantial gains in efficiency over conventional designs, and for hidden populations link-tracing and other adaptive procedures may provide the only practical way to obtain a sample large enough for the study objectives.

Adolescent↗
PubMed1992

Responses of airway rapidly adapting receptors to bradykinin before and after administration of enalapril in rabbits.

1. The present study was performed in anaesthetized, artificially ventilated, open-chested rabbits to examine whether (a) the rapidly adapting receptors of the airways were stimulated by exogenously administered bradykinin, and (b) if this sensitivity could be enhanced by the angiotensin-converting-enzyme inhibitor, enalapril. 2. Rapidly adapting receptor activity (n = 8) was recorded from the cervical vagus. Bradykinin was injected intravenously (0.25-1.0 microgram/kg) and a dose-response curve relating receptor activity to bradykinin was elicited. In the control state, the threshold dose of bradykinin required for stimulation of rapidly adapting receptors was 0.53 +/- 0.11 microgram/kg. Five minutes after the administration of enalapril maleate (2 mg intravenously), the dose-response curve was shifted to the left significantly (P < 0.01). 3. In seven other rapidly adapting receptors, enalapril (2 mg) increased the resting activity significantly (P < 0.05) over a period of 60 min. This increase was significantly different from the spontaneous variation in neural activity of rapidly adapting receptors (n = 7) recorded over a period of 60 min. 4. Bradykinin either alone (0.25-1.0 microgram/kg) or in the presence of enalapril did not stimulate the slowly adapting receptors (n = 5) of the airways. 5. These results show that (a) exogenous bradykinin stimulates the rapidly adapting receptors, (b) the sensitivity of rapidly adapting receptors to bradykinin is enhanced by enalapril and (c) enalapril increases the resting activity of rapidly adapting receptors. It is suggested that the cough reported after the administration of enalapril may be due to stimulation of rapidly adapting receptors of the airways.

Action Potentials↗
PubMed1978

Effects of two types of motor practice on stuttering adaptation.

The present study identifies and compares the effects of two types of motor practice on stuttering adaptation. The study was designed to determine if whispered reading practice affects stuttering adaptation, and if practice in reading aloud is superior to whispered reading in promoting adaptation. In a control condition, eight stutterers read one of two matched passages aloud five times in succession. In an experimental condition, the remaining passage was read aloud on the first and fifth trials, and was read in a whisper on Trials 2, 3, and 4. The results indicated that (1) the stutterers' adaptation in the control condition was similar to the typical course of adaptation, (2) the three intervening whispered readings in the experimental condition neither inhibited nor facilitated adaptation, and (3) practice in reading aloud was superior to whispered practice in promoting stuttering adaptation. It was concluded that whispered reading practice does not facilitate stuttering adaptation when the measurement of that process requires reading aloud. Traditionally, adaptation has been measured only during reading done aloud. Consequently, practice in reading aloud has the greatest positive influence on the adaptation process.

Adolescent↗
PubMed1993

Attentional effects of adaptation of rotary motion in the plane.

The effect of attention on the adaptation effects produced by stimuli rotating in the picture plane was examined in five experiments. In experiment 1, subjects performed a task either on a rotating adapting stimulus or on an irrelevant distractor stimulus. Adaptation of a subsequent ambiguous test stimulus was greater when the adapting stimulus was attended than when the irrelevant stimulus was attended. In experiments 2, 3, and 5, two adapting stimuli were presented, rotating in opposite directions, and subjects attended to one or the other. The direction of rotation of the ambiguous test stimulus depended on which adapting stimulus was attended. In experiment 4, the influence of eye movements in producing adaptation in ambiguous motion displays was determined by contrasting the effects of adaptation produced by dual adaptation stimuli rotating in the same or opposite direction. Adaptation effects were not predicted by eye movement hypotheses.

Attention↗
PubMed1982

Renal transport of taurine adapts to perturbed taurine homeostasis.

Renal adaptation apparently contributes to the homeostasis of taurine, a beta-amino compound that behaves as a conserved metabolite in the mammal. We studied two strains of inbred mice: C3H/HeJ (low-taurine excreter) and C57BL/6J (high-taurine excreter due to impaired basolateral membrane permeability to taurine). Low-protein and low-sulfur amino acid diets fed for two weeks significantly decreased plasma taurine in both strains, decreased fractional taurine excretion in vivo (particularly in the C57BL strain), and increased net uptake of taurine by renal cortex slices and isolated brush-border membrane vesicles (BBMV) in vitro in both strains. Renal adaptation was less obvious in vivo in the low-taurine excreter C3H strain, but in vitro adaptation, as observed in slices and BBMV (P less than 0.01), was greater than that observed in the C57BL strain. Renal cellular taurine content fell (P less than 0.01) only in the adapted C3H strain. The in vitro adaptive response was not confined to taurine; BBMV uptake of D-glucose and L-alanine was also enhanced in the adapted state. Specificity of the stimulus for adaptation was tested with a low-phenylalanine diet; a modest adaptation was observed in vivo and in vitro but only in the C3H strain. BBMV adaptation did not correlate with blood methionine but correlated inversely with plasma taurine (r = 0.71, P less than 0.05), implying that change in extracellular taurine may be a signal for renal adaptation in taurine homeostasis in the mammal.

Amino Acids↗