Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Physiological responses to acute stress were assessed in alloxan diabetic, streptozotocin diabetic and control laboratory rats. Rats were prepared with indwelling tail artery catheters to allow for direct measurement of mean arterial pressure (MAP, mmHg) and heart rate (HR, beats per minute) and remote sampling of blood. Within 24 hours after surgery, basal values of MAP and HR were determined. Two days after surgery, rats were subjected to 5 minutes of intermittent footshock. Blood samples were collected before footshock stress and immediately and 15 minutes after termination of footshock. Plasma levels of norepinephrine (NE) and epinephrine (EPI) increased significantly above basal values in all animals exposed to acute footshock stress. However, in approximately one-half of alloxan and streptozotocin diabetic rats, plasma levels of EPI under basal conditions and following footshock stress were elevated significantly compared to controls and the remaining diabetic animals. We have denoted these subgroups of diabetic animals as reactive responders (plasma EPI greater than controls) and nonreactive responders (plasma EPI similar to controls), respectively. Plasma levels of NE under basal conditions and following footshock stress were similar in reactive responders and nonreactive responders compared to matched controls. Baseline blood glucose levels were elevated in alloxan and streptozotocin diabetic rats compared to controls. Blood glucose levels increased reliably in all animals following footshock stress. Basal MAPs were reduced significantly in both subgroups of alloxan and streptozotocin diabetic rats compared to matched controls. In contrast, resting HRs were similar between diabetic rats and their corresponding controls.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Physiological responses to acute stress in alloxan and streptozotocin diabetic rats. 252 54

Sympathetic-adrenal medullary responses to acute footshock stress were assessed in inbred Dahl salt-sensitive (S/JR) and salt-resistant (R/JR) rats by measuring plasma levels of norepinephrine (NE) and epinephrine (EPI). Ten-week-old S/JR and R/JR rats were surgically prepared with indwelling tail artery catheters which permitted direct measurements of mean arterial pressure (MAP, mmHg) and heart rate (HR, beats/min) and remote sampling of blood. Two days after surgery, S/JR and R/JR rats were subjected to an acute stress paradigm. Blood samples were collected before and 3 minutes after transfer of rats to a shock chamber, after 1 minute of intermittent footshock, and again 5 minutes later. S/JR rats had significantly higher resting MAP's compared to R/JR rats. In contrast, baseline heart rates were similar for rats of the two strains. Basal plasma levels of NE and EPI were also similar in S/JR and R/JR rats. Upon transfer from the home cage to a shock chamber, S/JR rats exhibited significant increases in plasma levels of both catecholamines, while R/JR rats maintained circulating levels of NE and EPI that were near baseline values. However, S/JR and R/JR rats had similar increments in plasma NE and EPI following acute footshock stress. Five minutes after footshock, levels of NE and EPI returned toward baseline values for R/JR's, but remained significantly elevated above baseline in hypertensive S/JR rats. These data suggest that S/JR rats are more responsive than R/JR controls to the mild stress of transfer, but exhibit comparable responses to the more intense stress of inescapable footshock.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Sympathetic-adrenal medullary responses to acute stress in Dahl hypertensive (S/JR) rats. 272 39

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.
 ...
PMID:Neonatal hyperthyroidism: effects on sympathetic responses to stress in adult rats. 686 80

There is evidence that alterations in heart rate and blood pressure variability (BPV) are associated with cardiovascular disease. We used a mice model to investigate the effects of acute and chronic stress on blood pressure variability (BPV) and heat rate variability (HRV). Shaker stress was given acutely (5 min, 150 cycles/min) and chronically (3 days, 2 min stress, 150 cycles/min, 45 sessions/day) in male C57BLJ mice. Systolic arterial pressure (SAP) and pulse interval (PI) time series were submitted to autoregressive spectral analysis with variability measured in the low-frequency (LF, 0.1-1.0 Hz) and high-frequency (HF, 1-5 Hz) ranges. In the acute experiment, MAP was increased significantly in the first 10 min poststress period (99+/-2 vs. 113+/-2 mm Hg) and returned to control levels 30 min poststress. HR was significantly higher in the initial poststress period (537+/-12 vs. 615+/-20 bpm). These alterations were associated with a marked increase in BPV (21+/-4 vs. 55+/-11 mm Hg2) and in power of LF oscillations (18+/-3 vs. 42+/-7 mm Hg2). On the other hand, chronic stress exposure produced a reduction in BPV (16+/-4 vs. 6+/-1 mm Hg2) and LF oscillations (11+/-3 vs. 3+/-1 mm Hg2). HRV was not altered after either acute or chronic stress. Spontaneous baroreflex sensitivity (SBS), determined by cross-spectral analysis between PI and BP, was reduced significantly in acute stress (-50%), but unchanged in chronic stress. Our results show that acute stress produced changes in BPV that may be associated with increased sympathetic activity and a reduction in blood pressure buffering. Under chronic conditions, there is no alteration in baroreflex sensitivity while BPV is reduced. This is likely related to the combination of sympathetic activation in the face of vasculature alterations.
 ...
PMID:Acute and chronic stress influence blood pressure variability in mice. 1550