Age-related Impairments on the Touchscreen Paired Associates Learning (PAL) Task in Male Rats

2021 ◽  
Author(s):  
Samantha M. Smith ◽  
Sabrina Zequeira ◽  
Meena Ravi ◽  
Sarah A. Johnson ◽  
Andriena M. Hampton ◽  
...  
Keyword(s):  
Male Rats ◽  
Paired Associates ◽  
Age Related

Effects of trenbolone acetate and testosterone on growth and on plasma concentrations of corticosterone and ACTH in rats

1990 ◽  
Vol 126 (3) ◽  
pp. 461-466 ◽  
Author(s):  
M. N. Sillence ◽  
R. G. Rodway
Keyword(s):  
Weight Gain ◽  
Growth Response ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Male Rats ◽  
Adrenal Weight ◽  
Trenbolone Acetate ◽  
Male And Female Rats ◽  
Age Related ◽  
Old Rats

ABSTRACT The effects of trenbolone acetate (TBA) on growth and on plasma concentrations of corticosterone were examined in male and female rats. At 5 weeks of age, rats were injected with TBA (0·8 mg/kg) dissolved in peanut oil, or with oil alone, daily for 10 days. In female rats, TBA caused an increase in weight gain (20–38%), a reduction in adrenal weight (19%) and a reduction in plasma concentrations of corticosterone (55%). In contrast, TBA-treated male rats showed no significant increase in weight gain, no significant change in adrenal weight and no reduction in plasma concentrations of corticosterone. The mechanism by which adrenal activity was suppressed in TBA-treated female rats was examined and the response compared with that to testosterone. Female rats (8 weeks old) were injected daily either with oil vehicle, TBA (0·8 mg/kg) or testosterone propionate (0·8 mg/kg). Testosterone increased weight gain (24%), but the growth response to TBA treatment was significantly greater (97%). A reduction in plasma concentrations of corticosterone (45%) was again observed in response to TBA. However, testosterone increased plasma concentrations of corticosterone (52%) above those of control values. Neither androgen affected plasma concentrations of ACTH. Finally, the effects of TBA were examined in 6-week-old female rats, to characterize further the apparent age-related increase in responsiveness. The growth response of 6-week-old rats (60–74%) was intermediate between that seen in 5- and 8-week-old animals. It is concluded that part of the anabolic activity of TBA may be related to a reduction in circulating concentrations of corticosterone. The effect of TBA on corticosterone concentrations differs from that of the natural androgen, testosterone, and does not appear to be mediated by a reduction in plasma concentrations of ACTH. Journal of Endocrinology (1990) 126, 461–466

scholarly journals The Relationship Between Hearing Loss and Cognitive Impairment in a Chinese Elderly Population: The Baseline Analysis

2021 ◽  
Vol 15 ◽  
Author(s):  
Xinxing Fu ◽  
Bo Liu ◽  
Shuo Wang ◽  
Robert H. Eikelboom ◽  
Dona M. P. Jayakody
Keyword(s):  
Older Adults ◽  
Hearing Loss ◽  
Cognitive Impairment ◽  
Health Care Professionals ◽  
Spatial Working Memory ◽  
Depression Anxiety Stress Scale ◽  
Paired Associates ◽  
Multiple Stepwise Regression Analysis ◽  
Age Related ◽  
Age Related Hearing Loss

Objectives: The objective of the study was to investigate the association between untreated age-related hearing loss and cognitive impairment in Mandarin-speaking older adults living in China.Methods: Older adults (293; 111 males, M = 70.33 ± 4.90 years; 182 females, M = 69.02 ± 4.08 years) were recruited. All participants completed a pure tone audiometric hearing assessment, Hearing Impairment-Montreal Cognitive Assessment Test (HI-MoCA), and a computerized neuropsychology test battery (CANTAB). The Mandarin version of the De Jong Gierveld Loneliness Scale was used to measure the loneliness, and the Mandarin version of the 21-item Depression Anxiety Stress Scale (DASS-21) was used to measure the current severity of a range of symptoms common to depression, stress, and anxiety of the participants.Results: A multiple stepwise regression analysis showed that the average of four mid-frequency thresholds in the better ear was related to CANTAB Paired Associates Learning (β = 0.20, p = 0.002), and the global cognitive function score (HI-MoCA) (β = −0.25, p < 0.001). The average of three high frequencies in the better ear was significantly associated with CANTAB Delayed Matching to Sample (β = −0.16, p = 0.008), and Spatial Working Memory (β = 0.17, p = 0.003).Conclusion: The results revealed a significant relationship between age-related hearing loss and cognitive impairment in Mandarin-speaking older adults. These research outcomes have clinical implications specifically for hearing health care professionals in China and other populations that speak a tonal language, especially when providing hearing rehabilitation.

Abstract 170: Arginase Contributes to Delayed Constriction of Large Cerebral Arteries in a Model of Subarachnoid Hemorrhage

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Weiyun Sun ◽  
Kathleen K Kibler ◽  
Herman Kwansa ◽  
Ewa Kulikowicz ◽  
Weizhu Tang ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Ex Vivo ◽  
Cerebral Arteries ◽  
Arginase Activity ◽  
Male Rats ◽  
Control Value ◽  
Age Related ◽  
Arterial Constriction ◽  
Oxide Synthase ◽  
Nitric Oxide Synthase Activity

Introduction: Increased arginase activity can limit nitric oxide synthase activity and contribute to age-related increase in aortic stiffness. Hypothesis: Subarachnoid hemorrhage (SAH) produces a delayed increase in arginase activity that contributes to delayed decreases in diameter of major cerebral arteries. Methods: Male rats underwent injection of blood into the cisterna magna on day 0 and again on day 2. Shams had double injection of artificial CSF. Measurements of arginase activity on vessels in the Circle of Willis and pia matter were made with an assay based on the conversion of radiolabeled arginine to urea. Measurements of diameter of basilar, posterior (PCA), middle (MCA), and anterior (ACA) cerebral arteries were made ex vivo after perfusion with paraformaldehyde and black latex casting. Results: Arginase activity (nmol of urea/min/mg of protein) increased from the control value of 13±3 (±SE; n=17) to 24±6 (n=6) at 3 days, 36±14 (n=4) at 5 days, and 48±16 (n=9) at 7 days after SAH and then recovered at 10 days (14±5; n=4) and 14 days (18±6; n=5) after SAH. Infusion of the arginase inhibitor 2(S)-amino-6-boronohexanoic acid (ABH) for 7 days after SAH with an ip osmotic pump blocked the increase in arginase activity (10±2; n=4). Assessment of arterial diameter at 3, 5, 7, 10, and 14 days after SAH revealed the smallest diameters occurring at 7 days (except for MCA which occurred at 5 days). Continuous ip infusion of 10 mg/kg/day ABH significantly attenuated the decrease in diameter (μm) 7 days after SAH in PCA (sham = 249±9, n=8; SAH = 209±12, n=10; SAH+ABH = 255±9, n=6) and ACA (sham = 178±11; SAH = 141±11; SAH+ABH = 198±10). Effects on basilar artery were of marginal significance (P=0.065). Conclusion: SAH produces an increase in vascular arginase activity that is temporally related to delayed decreases in diameter of cerebral arteries. Inhibition of arginase activity prevents the decrease in diameter at 7 days after SAH, thereby indicating a contribution of arginase to delayed arterial constriction/remodeling in post-fixed arteries.

Age-related susceptibility to muscle damage following mechanotherapy in rats recovering from disuse atrophy

2021 ◽  
Author(s):  
Zachary R Hettinger ◽  
Kyoko Hamagata ◽  
Amy L Confides ◽  
Marcus M Lawrence ◽  
Benjamin F Miller ◽  
...  
Keyword(s):  
Older Adults ◽  
Muscle Mass ◽  
Older Adult ◽  
Recovery Period ◽  
Male Rats ◽  
Hindlimb Suspension ◽  
Disuse Atrophy ◽  
Adult Rats ◽  
Transverse Stiffness ◽  
Age Related

Abstract The inability to fully recover lost muscle mass following periods of disuse atrophy predisposes older adults to lost independence and poor quality of life. We have previously shown that mechanotherapy at a moderate load (4.5 N) enhances muscle mass recovery following atrophy in adult, but not older adult rats. We propose that elevated transverse stiffness in aged muscle inhibits the growth response to mechanotherapy and hypothesize that a higher load (7.6 N) will overcome this resistance to mechanical stimuli. F344/BN adult and older adult male rats underwent 14-days of hindlimb suspension, followed by 7-days of recovery with (RE+M) or without (RE) mechanotherapy at 7.6 N on gastrocnemius muscle. The 7.6 N load was determined by measuring transverse passive stiffness and linearly scaling up from 4.5 N. No differences in protein turnover or mean fiber cross sectional area were observed between RE and RE+M for older adult rats or adult rats at 7.6 N. However, there was a higher number of small muscle fibers present in older adult, but not adult rats, which was explained by a 16-fold increase in the frequency of small fibers expressing embryonic myosin heavy chain. Elevated central nucleation, satellite cell abundance, and dystrophin -/laminin + fibers were present in older adult rats only following 7.6 N, while 4.5 N did not induce damage at either age. We conclude that age is an important variable when considering load used during mechanotherapy and age-related transverse stiffness may predispose older adults to damage during the recovery period following disuse atrophy.

Melatonin Prevents the Development of Age-Related Pathology in Male Rats during Accelerated Aging Caused by Impaired Photoperiodism

2021 ◽  
Vol 11 (1) ◽  
pp. 77-82
Author(s):  
I. A. Vinogradova ◽  
Yu. P. Matveeva ◽  
O. V. Zhukova ◽  
V. D. Yunash ◽  
V. N. Anisimov
Keyword(s):  
Accelerated Aging ◽  
Male Rats ◽  
Age Related

Age-induced hypercholesterolemia in the rat relates to reduced elimination but not increased intestinal absorption of cholesterol

2007 ◽  
Vol 293 (3) ◽  
pp. E737-E742 ◽  
Author(s):  
Cecilia Gälman ◽  
Manuela Matasconi ◽  
Lena Persson ◽  
Paolo Parini ◽  
Bo Angelin ◽  
...  
Keyword(s):  
Intestinal Absorption ◽  
Plasma Cholesterol ◽  
Scavenger Receptor ◽  
Cholesterol Absorption ◽  
Male Rats ◽  
Gh Treatment ◽  
Ldl Receptors ◽  
Age Related ◽  
Class B

Plasma cholesterol increases in normal aging in both rodents and humans. This is associated with reduced elimination of cholesterol as bile acids (BAs) and decreased receptor-mediated clearance of plasma LDL, changes that can be reversed by treatment with growth hormone (GH). The level of intestinal absorption of cholesterol may also contribute to the development of hypercholesterolemia. In this study, we investigated whether cholesterol absorption increases with age and whether any such age-related change could be influenced by treatment with GH or ezetimibe (EZE). Male rats aged 6 and 18 mo were studied with and without GH or EZE treatment. BA synthesis was reduced and plasma cholesterol was increased in the old animals, whereas cholesterol absorption was unaltered. Cholesterol absorption was not altered by GH treatment but was reduced by EZE in both groups of animals. Hepatic LDL receptors (LDLRs), scavenger receptor class B type 1, and proprotein convertase subtilisin/kexin type 9 serine protease (PCSK9) transcripts were unchanged in old animals. GH treatment induced LDLRs, PCSK9 transcripts, and BA synthesis. We conclude that the age-induced hypercholesterolemia in the rat and its reversal by GH treatment relates to altered degradation of cholesterol in the liver and is not due to changes in cholesterol absorption.

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