Locus Coeruleus Noradrenergic Modulation of Diurnal Corticosterone, Stress Reactivity and Cardiovascular Homeostasis in Male Rats

2021 ◽  
Author(s):  
K.V. Thrivikraman ◽  
Becky Kinkead ◽  
Michael J. Owens ◽  
Mark H. Rapaport ◽  
Paul M. Plotsky

Introduction: Activation of the locus coeruleus-noradrenergic (LC-NA) system during awakening is associated with an increase in plasma corticosterone and cardiovascular tone. These studies evaluate the role of the LC in this corticosterone and cardiovascular response. Methods: Male rats, on day 0, were treated IP with either DSP4 (50 mg/ kg body weight) (DSP), a LC-NA specific neurotoxin, or normal saline (SAL). On day 10, animals were surgically prepared with jugular vein [Hypothalamic–pituitary–adrenal (HPA) axis] or carotid artery (hemodynamics) catheters and experiments performed on day 14. HPA axis activity, diurnally (circadian) and after stress [transient hemorrhage (14 mL/kg body weight) or airpuff-startle], and basal and post-hemorrhage hemodynamics were evaluated. On day 16, brain regions from a subset of rats were dissected for norepinephrine and corticotropin-releasing factor (CRF) assay. Results: In DSP rats compared to SAL rats: 1) regional brain norepinephrine was decreased but there was no change in median eminence or olfactory bulb CRF content; 2) during HPA axis acrophase, the plasma corticosterone response was blunted; 3) after hemorrhage and airpuff-startle, the plasma adrenocorticotropic hormone response was attenuated, whereas the corticosterone response was dependent on stressor category; 4) under basal conditions, hemodynamic measures exhibited altered blood flow dynamics and systemic vasodilation; and 5) after hemorrhage, hemodynamics exhibited asynchronous responses. Conclusion: LC-NA modulation of diurnal and stress-induced HPA axis reactivity occurs via distinct neurocircuits. The integrity of the LC-NA system is important to maintain blood flow dynamics. The importance of increases in plasma corticosterone at acrophase to maintain short- and long-term cardiovascular homeostasis is discussed.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Irina P. Butkevich ◽  
Viktor A. Mikhailenko ◽  
Tat'yana R. Bagaeva ◽  
Elena A. Vershinina ◽  
Anna Maria Aloisi ◽  
...  

Our researches have shown that gestational stress causes exacerbation of inflammatory pain in the offspring; the maternal 5-HT1A agonist buspirone before the stress prevents the adverse effect. The serotonergic system and hypothalamo-pituitary-adrenal (HPA) axis are closely interrelated. However, interrelations between inflammatory pain and the HPA axis during the hyporeactive period of the latter have not been studied. The present research demonstrates that formalin-induced pain causes a gradual and prolonged increase in plasma corticosterone level in 7-day-old male rats; twenty-four hours after injection of formalin, the basal corticosterone level still exceeds the initial basal corticosterone value. Chronic treatments of rat dams with buspirone before restraint stress during gestation normalize in the offspring pain-like behavior and induce during the acute phase in the formalin test the stronger corticosterone increase as compared to the stress hormonal elevation in animals with other prenatal treatments. Negative correlation between plasma corticosterone level and the number of flexes+shakes is revealed in buspirone+stress rats. The new data enhance the idea about relativity of the HPA axis hyporeactive period and suggest that maternal buspirone prior to stress during gestation may enhance an adaptive mechanism of the inflammatory nociceptive system in the infant male offspring through activation of the HPA axis peripheral link.


2011 ◽  
Vol 300 (2) ◽  
pp. F319-F329 ◽  
Author(s):  
Niels-Henrik Holstein-Rathlou ◽  
Olga V. Sosnovtseva ◽  
Alexey N. Pavlov ◽  
William A. Cupples ◽  
Charlotte Mehlin Sorensen ◽  
...  

Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50–100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Tai-Yuan Chuang ◽  
Chia-Ying Lien ◽  
Chih-Hsiang Hsu ◽  
Chen-Wen Lu ◽  
Chung-Hsin Wu

Hypothyroidism frequently causes cardiopulmonary dysfunction, such as heart failure and respiratory and metabolic deficiencies. This study investigated the effects of Chinese herbal formula B307 on thyroidectomy-induced cardiopulmonary exercise dysfunction in rats. Twenty male rats were equally divided into four groups: negative control with sham treatment, positive control with oral B307 treatment only, thyroidectomy treatment only, and thyroidectomy with B307 posttreatment groups. The feeding dose of B307 was 50 mg/kg per day for 14 days. We examined and then compared the thyroid-stimulating hormone (TSH), free triiodothyronine (T3), free thyroxine (T4), and reactive oxygen species (ROS) from the blood of these four groups. Also, we compared the body weight, neck subcutaneous blood flow, cardiac ejection function, cardiopulmonary exercise function of oxygen consumption (VO2), carbon dioxide production (VCO2), and respiratory quotient (RQ = VCO2/VO2) among the four groups. Our results indicated that thyroidectomized rats had significantly decreased body weight, neck subcutaneous blood flow, cardiac ejection function, serum T3 and T4, and VO2 and VCO2, but had significantly increased ROS and TSH levels and RQ values compared with sham rats (P<0.01–0.05). In addition, thyroidectomized rats receiving oral B307 treatment had significantly increased body weight, neck subcutaneous blood flow, cardiac ejection function, and VO2, but significantly decreased ROS and TSH levels and VCO2 and RQ values compared with thyroidectomized rats (P<0.01–0.05). We suggest that the B307 could be a protective and beneficial alternative treatment for thyroidectomy-induced cardiopulmonary exercise dysfunction.


2006 ◽  
Vol 38 (10) ◽  
pp. 1811-1818 ◽  
Author(s):  
MICHAEL E. TSCHAKOVSKY ◽  
NATASHA R. SAUNDERS ◽  
KATHERINE A. WEBB ◽  
DENIS E. O'DONNELL

1990 ◽  
Vol 8 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Q. Guo ◽  
L. Friloux ◽  
O. Nalcioglu

The Analyst ◽  
2015 ◽  
Vol 140 (5) ◽  
pp. 1432-1437 ◽  
Author(s):  
Shantimoy Kar ◽  
Monika Dash ◽  
Tapas Kumar Maiti ◽  
Suman Chakraborty

We investigate blood flow dynamics on a rotationally actuated lab-on-a-compact disk (LOCD) platform, as a function of the hematocrit level of the blood sample.


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