scholarly journals Effects of perinatal oxycodone exposure on the cardiovascular response to acute stress in male rats at weaning and in young adulthood

2013 ◽  
Vol 4 ◽  
Author(s):  
Thitinart Sithisarn ◽  
Henrietta S. Bada ◽  
Richard J. Charnigo ◽  
Sandra J. Legan ◽  
David C. Randall
Keyword(s):  
Young Adulthood ◽  
Acute Stress ◽  
Cardiovascular Response ◽  
Male Rats

The ultrastructure of acinar cells in the external orbital gland of young and old male rats

1978 ◽  
Vol 36 (2) ◽  
pp. 276-277
Author(s):  
R. Carriere
Keyword(s):  
Young Adulthood ◽  
Acinar Cells ◽  
Cell Number ◽  
Male Rats ◽  
Polyploid Cell ◽  
Secretory Cells ◽  
Age Changes ◽  
Albino Rat ◽  
Golgi Membranes ◽  
Diploid Cells

The external orbital gland of the albino rat exhibits both sexual dimorphism and histological age changes. In males, many cells attain a remarkable degree of polyploidy and an increase of polyploid cell number constitutes the major age change until young adulthood. The acini of young adults have a small lumen and are composed of tall serous cells. Subsequently, many acini acquire a larger lumen with an irregular outline while numerous vacuoles accumulate throughout the secretory cells. At the same time, vesicular acini with a large lumen surrounded by pale-staining low cuboidal diploid cells begin to appear and their number increases throughout old age. The fine structure of external orbital glands from both sexes has been explored and in considering acinar cells from males, emphasis was given to the form of the Golgi membranes and to nuclear infoldings of cytoplasmic constituents.

scholarly journals INDIVIDUAL DIFFERENCES IN EMOTION REGULATION AND CARDIOVASCULAR RESPONDING TO STRESS

2021 ◽  
Author(s):  
Siobhán M Griffin ◽  
Siobhán Howard
Keyword(s):  
Blood Pressure ◽  
Emotion Regulation ◽  
Individual Differences ◽  
Acute Stress ◽  
Negative Emotion ◽  
Cardiovascular Response ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Emotional Valence ◽  
Emotion Words

Instructed use of reappraisal to regulate stress in the laboratory is typically associated with a more adaptive cardiovascular response to stress, indexed by either: (i) lower cardiovascular reactivity (CVR; e.g., lower blood pressure); or (ii) a challenge-oriented response profile (i.e., greater cardiac output paired with lower total peripheral resistance). In contrast, instructed use of suppression is associated with exaggerated CVR (e.g., greater heart rate, blood pressure). Despite this, few studies have examined if the habitual use of these strategies are related to cardiovascular responding during stress. The current study examined the relationship between cardiovascular responses to acute stress and individual differences in emotion regulation style: trait reappraisal, suppression, and emotion regulation difficulties. Forty-eight participants (25 women, 23 men) completed a standardised laboratory stress paradigm incorporating a 20-minute acclimatization period, a 10-minute baseline, and two 5-minute speech tasks separated by a 10-minute inter-task rest period. The emotional valence of the speech task was examined as a potential moderating factor; participants spoke about a block of negative-emotion words and a block of neutral-emotion words. Cardiovascular parameters were measured using the Finometer Pro. Greater habitual use of suppression was associated with exaggerated blood pressure responding to both tasks. However, only in response to the negative-emotion task was greater use of reappraisal associated with a challenge-oriented cardiovascular response. The findings suggest that individual differences in emotion regulation translate to differing patterns of CVR to stress, but the emotional valence of the stressor may play a role.

Effects of intrahypothalamic crystalline steroids on acute ACTH secretion

1963 ◽  
Vol 205 (4) ◽  
pp. 671-673 ◽  
Author(s):  
Israel Chowers ◽  
Shaul Feldman ◽  
Julian M. Davidson
Keyword(s):  
Ascorbic Acid ◽  
Pituitary Gland ◽  
Median Eminence ◽  
Acute Stress ◽  
Testosterone Propionate ◽  
Experimental Period ◽  
Male Rats ◽  
Acth Secretion ◽  
Unilateral Adrenalectomy ◽  
Cortisol Implants

The respective roles of the hypothalamus and pituitary gland, in the inhibition of adrenocorticotropin secretion by corticoids, were studied by implanting small quantities of crystalline cortisol acetate in the median eminence region and pituitary of male rats. Adrenal weights and adrenal ascorbic acid depletion (AAAD) in response to the acute stress of unilateral adrenalectomy were measured 5, 10, 13, or 21 days postoperatively. Ten days following implantation in the hypothalamus, rats showed adrenal atrophy and inhibition of AAAD. Normal AAAD and slight adrenal hypertrophy were found 10 days after similar implantation of testosterone propionate in the median eminence. Animals with cortisol implants in the pituitary had normal adrenal weights and AAAD responses at this time. In rats with cortisol implants in the hypothalamus, an inhibition of AAAD was present after 5–6 days, had increased maximally at 13 days, and returned to normal at 21 days. Adrenal atrophy, however, was first noted at 10 days and adrenal weight continued to decline throughout the experimental period.

Neonatal hyperthyroidism: effects on sympathetic responses to stress in adult rats

1983 ◽  
Vol 245 (1) ◽  
pp. R95-R99
Author(s):  
R. McCarty ◽  
R. F. Kirby ◽  
P. C. Brunjes
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Plasma Levels ◽  
Acute Stress ◽  
Male Rats ◽  
Adult Rats ◽  
Basal Plasma ◽  
Repeated Sampling ◽  
Neonatal Hyperthyroidism ◽  
Sympathetic Nervous

Treatment of developing rats with thyroid hormone results in accelerated maturation of sympathetic and adrenal medullary responses to reflex activation of central sympathetic outflow. In this study, we examined the effects of neonatal hyperthyroidism on the responsiveness of the sympathetic nervous system of adult rats to acute stress. Hyperthyroidism was produced in Long-Evans hooded rats by injections of thyroxine (neo-T4, 1 mg/kg body wt) on postnatal days 1-4. Littermate controls received injections of vehicle only. In adulthood, male rats of the two groups were prepared with chronic tail artery catheters to allow repeated sampling of blood and direct measurements of mean arterial pressure (MAP, mmHg) and heart rate (HR, beats/min). Two days after surgery, rats were stressed by exposure to 1 min of inescapable foot shock (2.0 mA, 0.6-s duration, every 6 s). The activity of the sympathetic nervous system was assessed by measuring plasma levels of norepinephrine (NE) and epinephrine (E). Basal plasma levels of NE and E and resting MAP did not differ between neo-T4 and control rats. However, basal HR was elevated in neo-T4 rats. Footshock-induced increments in plasma levels of both catecholamines were greater in neo-T4 compared with control rats even though behavioral responses to footshock were similar across groups. However, neo-T4 rats were more active when tested in an open field on each of 3 consecutive days. These findings indicate that neonatal treatment with T4 results in hyperresponsiveness of the sympathoadrenal medullary system to acute stress that persists into adulthood.

scholarly journals Facilitation of the HPA Axis to a Novel Acute Stress Following Chronic Stress Exposure Modulates Histone Acetylation and the ERK/MAPK Pathway in the Dentate Gyrus of Male Rats

Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 2942-2952 ◽  
Author(s):  
Chantelle L. Ferland ◽  
Erin P. Harris ◽  
Mai Lam ◽  
Laura A. Schrader
Keyword(s):  
Dentate Gyrus ◽  
Histone Acetylation ◽  
Chronic Stress ◽  
Hpa Axis ◽  
Acute Stress ◽  
Male Rats ◽  
Stress Exposure ◽  
Erk Activation ◽  
Acute And Chronic Stress ◽  
Acute Stressor

Evidence suggests that when presented with novel acute stress, animals previously exposed to chronic homotypic or heterotypic stressors exhibit normal or enhanced hypothalamic-pituitary-adrenal (HPA) response compared with animals exposed solely to that acute stressor. The molecular mechanisms involved in this effect remain unknown. The extracellular signal-regulated kinase (ERK) is one of the key pathways regulated in the hippocampus in both acute and chronic stress. The aim of this study was to examine the interaction of prior chronic stress, using the chronic variable stress model (CVS), with exposure to a novel acute stressor (2,5-dihydro-2,4,5-trimethyl thiazoline; TMT) on ERK activation, expression of the downstream protein BCL-2, and the glucocorticoid receptor co-chaperone BAG-1 in control and chronically stressed male rats. TMT exposure after chronic stress resulted in a significant interaction of chronic and acute stress in all 3 hippocampus subregions on ERK activation and BCL-2 expression. Significantly, acute stress increased ERK activation, BCL-2 and BAG-1 protein expression in the dentate gyrus (DG) of CVS-treated rats compared with control, CVS-treated alone, and TMT-only animals. Furthermore, CVS significantly increased ERK activation in medial prefrontal cortex, but acute stress had no significant effect. Inhibition of corticosterone synthesis with metyrapone had no significant effect on ERK activation in the hippocampus; therefore, glucocorticoids alone do not mediate the molecular effects. Finally, because post-translational modifications of histones are believed to play an important role in the stress response, we examined changes in histone acetylation. We found that, in general, chronic stress decreased K12H4 acetylation, whereas acute stress increased acetylation. These results indicate a molecular mechanism by which chronic stress-induced HPA axis plasticity can lead to neurochemical alterations in the hippocampus that influence reactivity to subsequent stress exposure. This may represent an important site of dysfunction that contributes to stress-induced pathology such as depression, anxiety disorders, and posttraumatic stress disorder.

AEROBIC TRAINING ALTERS THE CARDIOVASCULAR RESPONSE TO ACUTE STRESS IN AFRICAN AMERICAN WOMEN 996

1997 ◽  
Vol 29 (Supplement) ◽  
pp. 174
Author(s):  
V. Bond ◽  
M. Roltsch ◽  
M. Caprarola ◽  
T. Mendez ◽  
P. Vaccaro ◽  
...  
Keyword(s):  
African American ◽  
African American Women ◽  
Aerobic Training ◽  
Acute Stress ◽  
Cardiovascular Response ◽  
American Women

Effects of Neuropeptides on Adenohypophyseal Hormone Response to Acute Stress in Male Rats*

Endocrinology ◽  
1979 ◽  
Vol 105 (1) ◽  
pp. 220-224 ◽  
Author(s):  
YVETTE TACHÉ ◽  
MARVIN BROWN ◽  
ROBERT COLLU
Keyword(s):  
Acute Stress ◽  
Male Rats ◽  
Hormone Response

Acute stress increases venomotor tone in conscious rats

1996 ◽  
Vol 271 (4) ◽  
pp. H1375-H1383 ◽  
Author(s):  
D. S. Martin ◽  
C. Appelt ◽  
M. C. Rodrigo ◽  
M. C. Egland
Keyword(s):  
Psychological Stress ◽  
Acute Stress ◽  
Cardiovascular Response ◽  
Pressor Response ◽  
Venous Pressure ◽  
Receptor Subtype ◽  
Indwelling Catheters ◽  
Conscious Rats ◽  
Air Jet ◽  
Acute Psychological Stress

This study tested the hypothesis that acute psychological stress causes venoconstriction. Male Sprague-Dawley rats were instrumented with indwelling catheters in a femoral artery and vein and a balloon-tipped catheter in the right atrium. Mean arterial pressure (MAP), venous pressure, heart rate (HR), and mean circulatory filling pressure (MCFP) were monitored in conscious rats. Air-jet stress was performed before and after treatment with saline, chlorisondamine, phentolamine, or prazosin. Air-jet stress caused MAP, HR, and MCFP to increase by 10 +/- 1 mmHg, 31 +/- 4 beats/min, and 0.95 +/- 0.09 mmHg, respectively. Treatment with either chlorisondamine or phentolamine was equally effective in abolishing the stress-induced increases in MAP, HR, and MCFP. Prazosin treatment abolished the pressor response to air-jet stress but did not significantly affect the HR and MCFP responses. In contrast, pretreatment with the alpha 2-receptor antagonist rauwolscine hydrochloride abolished both the MAP and MCFP responses to air-jet stress but did not affect the HR response. These findings indicate that venoconstriction is an important component of the cardiovascular response to acute psychological stress. Stress-induced venoconstriction appears to be mediated primarily via the alpha 2-receptor subtype.

Acute stress attenuates but does not abolish circadian rhythmicity of serum thyrotrophin and growth hormone in the rat

1996 ◽  
Vol 135 (6) ◽  
pp. 703-708 ◽  
Author(s):  
Octavi Martí ◽  
Amadeu Gavaldà ◽  
Trinidad John ◽  
Antonio Armario
Keyword(s):  
Growth Hormone ◽  
Food Intake ◽  
Acute Stress ◽  
Dark Period ◽  
Circadian Rhythmicity ◽  
Male Rats ◽  
Separate Experiment ◽  
Daily Rhythms ◽  
Tsh Secretion ◽  
Tsh Levels

Martí O, Gavaldà A, Jolín T, Armario A. Acute stress attenuates but does not abolish circadian rhythmicity of serum thyrotrophin and growth hormone in the rat. Eur J Endocrinol 1996;135:703–8. ISSN 0804–4643 The effects of acute immobilization (IMO) on daily rhythms of corticosterone, thyroid-stimulating hormone (TSH) and growth hormone (GH) were studied in adult male rats. Two hours of IMO increased serum corticosterone, this increase still being observed 3 h after finishing stress exposure. In the dark period corticosterone levels did not differ in control and IMO rats, but higher levels were observed again in the morning of the day after. Immobilization lowered serum GH and TSH levels throughout the 24-h period that followed exposure to the stressor. Such an effect was more marked in GH than in TSH. In addition, GH, but not TSH, levels were found to be reduced significantly by IMO at 08.30 h of the next day. None the less, daily rhythms of GH and TSH were still persistent and roughly similar to those of control rats. The daily rhythm of food intake was measured in a separate experiment and it was observed, as expected, that IMO reduced food intake only in the dark period of the lighting cycle. It appears therefore unlikely that IMO-induced anorexia was the major factor responsible for the inhibition of GH and TSH caused by IMO at 11.00 and 19.00 h, considering that the amount of food intake was very low and similar in control and IMO rats during this period. However, anorexia might have contributed to inhibition of GH and TSH secretion afterwards. Thus, in a third experiment we studied the contribution of IMO-induced anorexia to the changes in hormone levels observed 24 h after stress by introducing a group of pair-fed rats. It was found that IMO, but not pair-feeding, reduced TSH levels, whereas a similar reduction of GH was found in the two conditions. It might be concluded that acute stress transiently altered corticosterone secretion, the only long-lasting effect being a slight increase in its morning levels on the following stress. Immobilization also causes an inhibition of GH and TSH secretion in the rat that persists for several hours after finalization of exposure to the stressor, but daily rhythms were still apparent. It appears that the contribution of stress-induced anorexia is different in GH than in TSH. In conclusion, an acute severe stressor such as IMO, although modifying circulating levels of some hormones, particularly in the hours following exposure to the stressor, did not appear to interfere greatly with the expression of circadian rhythms of anterior pituitary hormones. Octavi Martí, Unitat de Fisiologia Animal, Facultat de Ciències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain

scholarly journals Impact of chronic catheterization and automated blood sampling (Accusampler) on serum corticosterone and fecal immunoreactive corticosterone metabolites and immunoglobulin A in male rats

2004 ◽  
Vol 180 (1) ◽  
pp. 145-153 ◽  
Author(s):  
F Royo ◽  
N Bjork ◽  
HE Carlsson ◽  
S Mayo ◽  
J Hau
Keyword(s):  
Diurnal Variation ◽  
Acute Stress ◽  
Immunoglobulin A ◽  
Blood Sampling ◽  
Male Rats ◽  
Sampling Device ◽  
Serum Corticosterone ◽  
Low Levels ◽  
Corticosterone Metabolites ◽  
Total Excretion

Jugular catheters were inserted in nine male rats under general isofluorane anesthesia and the catheters were connected to a commercially available computerized blood sampling device (Accusampler). Blood samples (150 microl) were collected every 4 h during the first 24 h after surgery and every 12 h during the following 72 h until 94 h after surgery, when the animals were killed. All fecal pellets were collected at blood sampling. Serum corticosterone and fecal concentrations of immunoreactive corticosterone metabolites and immunoglobulin A (IgA) were quantified by ELISAs. In blood, high corticosterone concentrations (>200 ng/ml) were recorded in the first samples obtained after surgery, but the concentrations decreased steadily during the day and became cyclical, showing a diurnal variation with high levels during evenings and low levels in the mornings. The automatic blood sampling itself did not result in recordable increases in serum corticosterone concentrations. The time delay between the presence of elevated corticosterone levels in blood and in feces was approximately 12 h. Fecal immunoreactive corticosterone metabolite levels remained elevated during the 94 h study period after surgery. The fecal concentrations of IgA showed substantial between-animal variation and decreased non-significantly after the surgery. Like serum corticosterone, fecal IgA showed a diurnal variation in amounts excreted, in this case with high values in the morning and low values in the evening. The concentrations of fecal corticosterone and IgA were negatively correlated in samples obtained before surgery but no correlation existed after surgery. This indicates that fecal immunoreactive corticosterone metabolites, but not IgA, constitute a good marker of acute stress. For immunoreactive corticosterone metabolites as well as for IgA, the concentration in feces correlated well with total excretion, making single fecal samplings usable as a measure of total secretion.

Sign in / Sign up

Export Citation Format

Share Document