Effects of Low-Level Cadmium Intake on the Contractility and Morphology of the Rat Aorta

1984 ◽  
Vol 3 (1) ◽  
pp. 13-24 ◽  
Author(s):  
J. L. Hart ◽  
E. C. Joyce
Keyword(s):  
Drinking Water ◽  
Structural Changes ◽  
Rat Aorta ◽  
Tension Development ◽  
Maximum Tension ◽  
Low Level ◽  
Age Related ◽  
Significant Difference ◽  
Blood Pressures ◽  
Age Related Changes

Female Long Evans hooded rats with an initial mean (± SE) weight of 85.7 ± 1.2 g were exposed to 5 ppm cadmium (Cd) in drinking water for 6 months. Rats which received no Cd in the drinking water served as untreated controls. Weights, systolic blood pressures (tail cuff method), several aspects of aortic ultrastructure, and isolated aortic contractile responses to epinephrine, angiotensin, and potassium chloride at 0, 1, 2, 3, and 6 months were observed in both groups. At none of the testing times was there a significant difference between the weights or systolic blood pressures of the control and Cd-treated groups. Analysis of variance indicated that aortas from control and Cd-treated rats showed similar age-related changes in maximum tension development (contractility) and similar threshold doses. However, Cd-treated aortas developed significantly less maximum tension than control aortas when compared at the same time intervals in response to all of the vasoconstrictors tested. This decreased contractility was apparent at one month and persisted at about the same level (20%) at 2, 3, and 6 months. There were also expected age-related changes in aortic ultrastructure of both groups, and although the 6-month Cd-treated aortas showed more degenerating endothelial cells, differences that might explain the consistent decreases in contractility of the Cd-treated aortas were not observed. The results of this study indicate that chronic low-level Cd treatment causes decreases in aortic contractility, as have previously been reported for acute exposure to Cd, but that this change is not associated with the development of hypertension or with structural changes in the aorta.

Influence of Regular Exercise on Age-Related Changes in Arterial Elasticity: Mechanistic Insights From Wall Compositions in Rat Aorta

2003 ◽  
Vol 28 (2) ◽  
pp. 204-212 ◽  
Author(s):  
Toshiya Nosaka ◽  
Hirofumi Tanaka ◽  
Izumi Watanabe ◽  
Masaaki Sato ◽  
Mitsuo Matsuda
Keyword(s):  
Elastic Modulus ◽  
Arterial Stiffness ◽  
Arterial Wall ◽  
Rat Aorta ◽  
Regular Exercise ◽  
Age Related ◽  
Significant Difference ◽  
Activity Groups ◽  
Age Related Changes ◽  
Related Increase

Arterial stiffness increases with age in healthy sedentary adults. We previously reported that the age-related increases in arterial stiffness are absent or attenuated in regularly exercising adults. However, the mechanism underlying this training effect is unknown. One possibility is that regular exercise minimizes age-related changes in the arterial wall composition of elastin and collagen. To gain insight into this issue, we studied four groups of rats (N = 23): young (42-46 wks) and old (80-84 wks), sedentary and exercise-trained. The exercise group swam 1 hr•d−1, 6 d•wk−1 for 17-21 weeks. There was no significant difference in the incremental elastic modulus between young sedentary and exercise-trained rats. The elastic moduli of the old exercise-trained rats were 31% lower than in the old sedentary controls. As such, the magnitude of age-related increase in the elastic modulus was smaller in the exercise-trained (110%) vs. the sedentary group (151%) (p < 0.05). In both activity groups, elastin content was lower and collagen content was higher in old vs. young rats (p < 0.05). However, there were no significant differences between the two activity groups. These results are not consistent with the hypothesis that regular physical exercise minimizes age-related compositional changes in the arterial wall and attenuates the age-related increase in arterial stiffness. Key words: elastin, collagen, exercise training

scholarly journals Age-related positivity effect on behavioural responses of dogs to human vocalisations

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Iris Smit ◽  
Dora Szabo ◽  
Enikő Kubinyi
Keyword(s):  
Emotional Processing ◽  
Positive Emotions ◽  
Attention And Memory ◽  
Positivity Effect ◽  
Behavioural Responses ◽  
Fundamental Frequencies ◽  
Age Related ◽  
Significant Difference ◽  
The Brain ◽  
Age Related Changes

AbstractAge-related changes in the brain can alter how emotions are processed. In humans, valence specific changes in attention and memory were reported with increasing age, i.e. older people are less attentive toward and experience fewer negative emotions, while processing of positive emotions remains intact. Little is yet known about this “positivity effect” in non-human animals. We tested young (n = 21, 1–5 years) and old (n = 19, >10 years) family dogs with positive (laugh), negative (cry), and neutral (hiccup, cough) human vocalisations and investigated age-related differences in their behavioural reactions. Only dogs with intact hearing were analysed and the selected sound samples were balanced regarding mean and fundamental frequencies between valence categories. Compared to young dogs, old individuals reacted slower only to the negative sounds and there was no significant difference in the duration of the reactions between groups. The selective response of the aged dogs to the sound stimuli suggests that the results cannot be explained by general cognitive and/or perceptual decline. and supports the presence of an age-related positivity effect in dogs, too. Similarities in emotional processing between humans and dogs may imply analogous changes in subcortical emotional processing in the canine brain during ageing.

scholarly journals Age-Related Changes in G Proteins in Rat Aorta

1996 ◽  
Vol 51A (2) ◽  
pp. B111-B116 ◽  
Author(s):  
S. L. Mader ◽  
C. L. Downing ◽  
J. Amos-Landgraf ◽  
P. Swebjka
Keyword(s):  
G Proteins ◽  
Rat Aorta ◽  
Age Related ◽  
Age Related Changes

scholarly journals The Oculomotor Systems Ability to Adapt to Structural Changes Caused by the Process of Senescence: A Review

2012 ◽  
Vol 5 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Jan Richard Bruenech ◽  
Inga-Britt Kjellevold Haugen ◽  
Ulla Bak ◽  
Marianne Maagaard ◽  
Frans VanderWerf
Keyword(s):  
Cortical Neurons ◽  
Structural Changes ◽  
Oculomotor System ◽  
Extraocular Muscles ◽  
Ocular Motility ◽  
Adaptive Mechanism ◽  
Perceptual Stability ◽  
Age Related ◽  
Retinal Information ◽  
Age Related Changes

Age-related binocular vision anomalies are frequently encountered during clinical examination of mature patients. Observations of both concomitant and incomitant restrictions in eye motility indicate that all oculomotor system levels are implicated, from cortical neurons down to extraocular muscles. The system can make adaptations in response to changes induced by growth and ageing, which it does by monitoring and adjusting its own performance. This adaptive mechanism, which is important for maintaining motility, spatial orientation, and perceptual stability, seems to rely on extra-retinal information about eye position in relation to the head and trunk. Receptors in the extraocular muscles and the vestibular system, assumed to contribute to this type of information, also undergo age-related changes. This may compromise their ability to assist in the adaptive process and in potential calibrations of other neural systems. Furthermore, recent observations of a dual, common, final pathway and double insertions of distal extraocular muscles suggest that muscle and tendon receptors may facilitate other, still unresolved, functions in the visual system. Consequently, age-related changes in certain mechanoreceptors may have more severe implications for ocular motility and visual functions than previously assumed. This review aims to detail some of the most frequent neurogenic and myogenic age-related changes that take place in the human oculomotor system and relevant pre-motor structures. It will also address clinical implications of these changes and the potential adaptive mechanism they initiate.

scholarly journals Age-related changes in circadian responses to dark pulses

2000 ◽  
Vol 279 (2) ◽  
pp. R586-R590 ◽  
Author(s):  
Marilyn J. Duncan ◽  
Anthony W. Deveraux
Keyword(s):  
Wheel Running ◽  
Activity Rhythm ◽  
Circadian Pacemaker ◽  
Running Activity ◽  
Age Related ◽  
Wheel Running Activity ◽  
Significant Difference ◽  
Time Signals ◽  
Dark Pulse ◽  
Age Related Changes

Aging involves many alterations in circadian rhythms, including a loss of sensitivity to both photic and nonphotic time signals. This study investigated the sensitivity of young and old hamsters to the phase advancing effect of a 6-h dark pulse on the locomotor activity rhythm. Each hamster was tested four times during a period of ∼9 mo; periods of exposure to a 14-h photoperiod were alternated with the periods of exposure to constant light (20–80 lx), during which the dark pulses were administered. There was no significant difference in the phase shifts exhibited by the young (4–10 mo) and old hamsters (19–25 mo) or in the amount of wheel running activity displayed during each dark pulse. However, young hamsters had a significantly greater propensity to exhibit split rhythms immediately after the dark pulses. These results suggest that, although aging does not reduce the sensitivity of the circadian pacemaker to this nonphotic signal, it alters one property of the pacemaker, i.e., the flexibility of the coupling of its component oscillators.

India Ink Pinprick Assessment of Age-Related Changes in the Cricoarytenoid Joint (CAJ) Articular Surfaces

1986 ◽  
Vol 29 (4) ◽  
pp. 536-543 ◽  
Author(s):  
Alice R. Kahn ◽  
Joel C. Kahane
Keyword(s):  
Structural Changes ◽  
Vocal Folds ◽  
Ground Substance ◽  
Articular Surfaces ◽  
India Ink ◽  
Age Related ◽  
Cricoarytenoid Joint ◽  
Functional Consequences ◽  
Vocal Quality ◽  
Age Related Changes

Age-related changes in the articular surfaces of the cricoarytenoid joints (CAJ) of 12 human Caucasian male larynges (6 age 19 to 30 years; 6 age 50 to 80 years) were investigated. Differences in color, roughness, ossification, and surface fiber organization were studied. These were correlated with changes in collagen fiber arrangement on the articular surfaces determined by an India ink pinprick technique. Consistent patterns of orientation of collagen fibers in CAJ surfaces were identified in young and old groups. Older articular surfaces exhibited extensive fibrillation and ossification, suggesting that articular cartilage undergoes alteration in ground substance and/or fiber structure as a function of age. CAJ cartilage changes in older males may limit range of motion of arytenoid cartilages and reduce degree and extent of vocal fold closure. These structural changes may produce negative functional consequences during voice production such as diminished vocal quality and reduced vocal intensity due to air leakage through incompletely or loosely approximated vocal folds.

Age-related changes in functional connectivity between young adulthood and late adulthood

2015 ◽  
Vol 7 (10) ◽  
pp. 4111-4122 ◽  
Author(s):  
Xin Xu ◽  
Qifan Kuang ◽  
Yongqing Zhang ◽  
Huijun Wang ◽  
Zhining Wen ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Young Adulthood ◽  
Brain Network ◽  
Late Adulthood ◽  
Functional Brain ◽  
Age Related ◽  
Functional Brain Network ◽  
Significant Difference ◽  
Network Metrics ◽  
Age Related Changes

The functional brain network in late adulthood has been found to show a significant difference from that in young adulthood using a variety of network metrics.

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