scholarly journals Vascular Response to Graded Angiotensin II Infusion in Offspring Subjected to High-Salt Drinking Water during Pregnancy: The Effect of Blood Pressure, Heart Rate, Urine Output, Endothelial Permeability, and Gender

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Zahra Pezeshki ◽  
Fatemeh Eshraghi-Jazi ◽  
Mehdi Nematbakhsh

Introduction.Rennin-angiotensin system and salt diet play important roles in blood pressure control. We hypothesized that the high-salt intake during pregnancy influences the degree of angiotensin-dependent control of the blood pressure in adult offspring.Methods.Female Wistar rats in two groups (A and B) were subjected to drink tap and salt water, respectively, during pregnancy. The offspring were divided into four groups as male and female offspring from group A (groups 1 and 2) and from group B (groups 3 and 4). In anesthetized matured offspring mean arterial pressure (MAP), heart rate and urine output were measured in response to angiotensin II (AngII) (0-1000 ng/kg/min, iv) infusion.Results.An increase in MAP was detected in mothers with salt drinking water (P<0.05). The body weight increased and kidney weight decreased significantly in male offspring from group 3 in comparison to group 1 (P<0.05). MAP and urine volume in response to AngII infusion increased in group 3 (P<0.05). These findings were not observed in female rats.Conclusion.Salt overloading during pregnancy had long-term effects on kidney weight and increased sex-dependent response to AngII infusion in offspring (adult) that may reveal the important role of diet during pregnancy in AngII receptors.

1992 ◽  
Vol 263 (5) ◽  
pp. R1030-R1034 ◽  
Author(s):  
J. D. Stone ◽  
J. T. Crofton ◽  
L. Share

In conscious, unrestrained rats, the intracerebroventricular injection of the cholinergic agonist, carbachol, or angiotensin II resulted in the transient stimulation of vasopressin secretion, elevation of mean arterial blood pressure, and reduction of heart rate. After the injection of carbachol (25 ng) into a lateral cerebral ventricle, the plasma vasopressin concentration in male rats was increased to twice that of female rats in each phase of the estrous cycle; mean arterial blood pressure was elevated more in males than females, whereas heart rate fell to the same extent in both sexes. In contrast, the increase in the plasma vasopressin concentration of males after the injection of angiotensin II (20 ng) was one-half that of females, and the hypertensive and bradycardic responses were similar in both sexes. Phase of the female estrous cycle had no effect on the responses to either agent. These findings indicate that central cholinergic and angiotensinergic mechanisms controlling vasopressin release are influenced differently by gender. The role of the gonadal steroid hormones in these mechanisms remains to be determined.


1967 ◽  
Vol 46 (2) ◽  
pp. 307-315 ◽  
Author(s):  
E. DON STEVENS ◽  
D. J. RANDALL

1. Changes in blood pressure in the dorsal aorta, ventral aorta and subintestinal vein, as well as changes in heart rate and breathing rate during moderate swimming activity in the rainbow trout are reported. 2. Blood pressures both afferent and efferent to the gills increased during swimming and then returned to normal levels within 30 min. after exercise. 3. Venous blood pressure was characterized by periodic increases during swimming. The pressure changes were not in phase with the body movements. 4. Although total venous return to the heart increased during swimming, a decreased blood flow was recorded in the subintestinal vein. 5. Heart rate and breathing rate increased during swimming and then decreased when swimming ceased. 6. Some possible mechanisms regulating heart and breathing rates are discussed.


2009 ◽  
Vol 22 (3) ◽  
Author(s):  
Lorenz van Doornen ◽  
Jan Houtveen

Physiological stress measures at work: relevance, limitations, and findings Physiological stress measures at work: relevance, limitations, and findings L. van Doornen & J. Houtveen, Gedrag & Organisatie, volume 22, September 2009, nr. 3, pp. 275-293 Physiological stress measures should only to a limited extent be considered as 'objective' indices of subjectively experienced work stress. Their contribution should mainly be sought in the quantification of the load on the body exerted by stress, the latter being the mediator of the health effects of work stress. For the most widely used physiological parameters in the field of work stress – blood pressure, heart rate, cardiac autonomic indices, adrenalin and cortisol – their physiology is described, their measurement techniques outlined, and an overall picture furnished with respect to differences observed between high- and low-work stress populations. Finally some suggestions are given with respect to future directions this field may take: focus on individual differences in physiological stress-sensitivity; quantification of recovery, and quantification of the effects of individual or workplace interventions.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Wararat Kittikulsuth ◽  
David M Pollock

Endothelin B (ET B ) receptors mediate vasodilation, anti-inflammation and natriuresis, which ultimately contribute to blood pressure control. We previously showed that renal medullary ET B receptor function is maintained in female angiotensin (Ang) II hypertensive rats, while male Ang II hypertensive rats have blunted ET B -induced natriuretic responses. Because female rats are more resistance to blood pressure elevation induced by high salt intake and/or Ang II infusion, we hypothesized that ET B receptors protect female rats against the hypertensive response and renal injury induced by a high salt diet and chronic Ang II infusion compared to males. Male and female rats received Ang II infusion (150 ng/kg/min; sc.) with 4% NaCl for 4 weeks; blood pressure was measured by telemetry. After a week of Ang II infusion with a high salt diet, subsets of both male and female rats received the ET B antagonist, A-192621, at three doses on consecutive weeks (1, 3, and 10 mg/kg/d in food). Male rats had a significantly higher blood pressure compared to females after 4 weeks of Ang II (178±10 vs. 138±10 mmHg; p<0.05). A-192621 resulted in a dose-dependent increase in blood pressure in female Ang II hypertensive rats (167±8 mmHg at 10 mg/kg/d; p<0.05); the increase produced by A-192621 in male Ang II hypertensive rats was not statistically significant (193±10 mmHg). After 4 weeks of Ang II infusion, the level of proteinuria and nephrinuria was higher in male rats compared to female. A-192621 did not further increase urinary excretion of protein or nephrin in both male and female Ang II hypertensive rats. In conclusion, these results support the hypothesis that ET B receptors provide more protection against hypertension during chronic Ang II infusion in female rats compared to male.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Keyona N King-Medina ◽  
Emily Henson ◽  
Pablo Ortiz

Human consumption of fructose as a sweetener has increased in the past 30 years. High fructose intake has been implicated in the development of hypertension, diabetes, and obesity. In the US, the upper 10th percentile of the population consumes up to 40% of their caloric intake from added sugars, in which fructose represents half of these. Fructose metabolism is strikingly different from that of glucose. Yet, the effect of a fructose or glucose-enriched diet in salt handling by the kidney, affecting blood pressure, and its interaction with high salt intake has been poorly studied. In genetic models of salt-sensitive hypertension, the activity of the Na + /K + /2Cl - cotransporter (NKCC2) in the thick ascending limb (TAL) is abnormally enhanced. We hypothesized that chronic fructose in drinking water induces a salt-dependent increase in blood pressure and stimulates NKCC2 during high salt intake in normal rats. Sprague-Dawley rats were given 20% fructose or 20% glucose in drinking water for 1 week after which a high salt (HS) diet (4% Na + in chow) was started for 3 weeks. When we measured systolic blood pressure (SBP) by tail cuff plethysmography in fructose-fed and glucose-fed rats on a HS diet, only the fructose-fed rats had an increased SBP from 120±10 to 132±6 mmHg on day 7 of HS (p<0.01). SBP continued to increase up to 144±18 mmHg after 3 weeks (p<0.01 vs glucose). Fructose or glucose alone did not increase SBP after 4 weeks. We then repeated the protocol using radiotelemetry to monitor the blood pressure (BP). In rats fed fructose, by day 5 of HS the SBP increased by 12±3 mmHg (p<0.02) and SBP remained elevated for 3 weeks (delta: 10±2.5 mmHg, n=3). In rats fed glucose, a HS diet did not significantly change SBP for 3 weeks (n=5). Moreover, NKCC2 activity in the TAL is enhanced by phosphorylation at Thr96, 101. We found that NKCC2 phosphorylation was higher in rats fed fructose plus HS (p<0.02) but not in rats fed glucose plus HS for 3 weeks (HS: 100, fructose+HS: 250±40%, glucose+HS: 95±10%). Therefore, we conclude that a high fructose (but not a glucose) diet in normal rats induces a salt-dependent increase in BP independently from caloric intake. Thus, the increase in BP may in part be due to the stimulation of NKCC2 phosphorylation in the TAL by fructose.


Author(s):  
Hugo Farne ◽  
Edward Norris-Cervetto ◽  
James Warbrick-Smith

You should ask the nurse: • What the trend is in urine output—has it been gradually decreasing, or suddenly stopped? If the latter, have they checked if the urinary catheter is blocked by flushing it? This is a rapidly reversible cause of poor urinary output. • What the observations are for the patient. Ask for the heart rate, blood pressure, respiratory rate, oxygen saturations, and temperature, so you can get an idea of how unwell the patient is. This will help you prioritize how soon you need to see the patient. Healthy adults have a urine output of about 1 mL/kg/hour. Oliguria refers to a reduced urine output and is defined variously as <400 mL/day, <0.5 mL/kg/hour, or <30 mL/hour. Anuria refers to the complete absence of urine output. Decreased urine output should be taken very seriously as it may be the first (and only) sign of impending acute renal failure. Untreated, patients may die from hyperkalaemia, profound acidosis, or pulmonary oedema due to the kidneys not performing their usual physiological role. Normal urine output requires: • adequate blood supply to the kidneys • functioning kidneys, and • flow of urine from the kidneys, down the ureters, into the bladder, and out via the urethra. Pathology affecting any of these requirements can result in poor urine output, which is why the differential diagnosis for poor urinary output is often classified as shown in Figure 22.1. In practice, as a junior doctor you want to diagnose and treat the prerenal and postrenal causes. If you come to the conclusion that it is a renal cause (by exclusion), call the renal physicians for an expert opinion. This is crucial in determining the diagnosis: • Adequate intake? Remember that an adult of average size will require about 3 L of fluid intake per 24 hours (30–50 mL/kg/day). Febrile patients will require an extra 500 mL for every 1 °C above 37.0 °C to compensate for increased loss of fluids from evaporation and increased respiratory rate.


2011 ◽  
pp. 141-148
Author(s):  
James R. Munis

Physiologist Claude Bernard lived in a time when very little was known about the mechanisms underlying physiologic findings, and he had ample access to clues garnered from observing machines. Let's consider homeostasis (a concept championed by Bernard), an example for which an engineered machine shed light on a fundamental principle of physiology. Homeostasis is simply the tendency of the body to maintain important physiologic variables (eg, heart rate, blood pressure, PACO2) at constant, preset values. An example is a simplified mechanical governor that could be used to regulate the rotational speed of a steam engine shaft. ‘Autoregulate’ might be a more apt word because the governor performs without external help or guidance, provided it is designed and built properly. It doesn't take much imagination to see an analogy between the mechanical governor and the autonomic nervous system. Both maintain specific variables at a constant set point through a process of feedback loops.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuenong Zhang ◽  
Zhiwen Zeng ◽  
Guangwen Xiao ◽  
Weiqiang Zhang ◽  
Weixiong Lin ◽  
...  

Abstract Background We aimed to evaluate a modified endotracheal tube containing upper and lower balloons for anesthetic administration among patients undergoing laparoscopic cholecystectomy. Methods Ninety patients scheduled to undergo laparoscopic cholecystectomy were randomly allocated to 3 equal groups: group A (conventional tracheal intubation without endotracheal anesthesia); B (conventional tracheal intubation with endotracheal anesthesia); and C (tracheal intubation using a modified catheter under study). Blood pressure, heart rate, angiotensin II level, blood glucose level, airway pressure before anesthesia (T1) were measured immediately after intubation (T2), 5 min after intubation (T3), and immediately after extubation (T4). The post-extubation pain experienced was evaluated using the Wong-Baker Face Pain scale. Adverse reactions within 30 min after extubation were recorded. Results Systolic blood pressure, diastolic blood pressure, angiotensin II, and blood sugar level in group C at T2, T3 and T4, and heart rate at T2 and T4 were significantly lower than those in group A (P < 0.05); systolic blood pressure and blood sugar at T4, and angiotensin II levels at T2, T3, and T4 were significantly lower than those in group B (P < 0.05). Patients in group C reported the lowest post-extubation pain (P < 0.05 vs. Group A), and the lowest incidence of adverse events such as nausea, vomiting, and sore throat than that in groups A and B (P < 0.05). Conclusion The modified endotracheal anesthesia tube under study is effective in reducing cardiovascular and tracheal stress response, and increasing patient comfort, without inducing an increase in airway resistance. Trial registration The clinical trial was retrospectively registered at the Chinese Clinical Trial Registry with the Registration Number ChiCTR1900020832 at January 20th 2019.


1991 ◽  
Vol 260 (3) ◽  
pp. E333-E337 ◽  
Author(s):  
C. K. Klingbeil ◽  
V. L. Brooks ◽  
E. W. Quillen ◽  
I. A. Reid

Angiotensin II causes marked stimulation of drinking when it is injected centrally but is a relatively weak dipsogen when administered intravenously. However, it has been proposed that the dipsogenic action of systemically administered angiotensin II may be counteracted by the pressor action of the peptide. To test this hypothesis, the dipsogenic action of angiotensin II was investigated in dogs, in which low and high baroreceptor influences had been eliminated by denervation of the carotid sinus, aortic arch, and heart. In five sham-operated dogs, infusion of angiotensin II at 10 and 20 ng.kg-1.min-1 increased plasma angiotensin II concentration to 109.2 +/- 6.9 and 219.2 +/- 38.5 pg/ml and mean arterial pressure by 20 and 29 mmHg, respectively, but did not induce drinking. In four baroreceptor-denervated dogs, the angiotensin II infusions produced similar increases in plasma angiotensin II concentration and mean arterial pressure but, in contrast to the results in the sham-operated dogs, produced a dose-related stimulation of drinking. Water intake with the low and high doses of angiotensin II was 111 +/- 44 and 255 +/- 36 ml, respectively. The drinking responses to an increase in plasma osmolality produced by infusion of hypertonic sodium chloride were not different in the sham-operated and baroreceptor-denervated dogs. These results demonstrate that baroreceptor denervation increases the dipsogenic potency of intravenous angiotensin II and provides further support for the hypothesis that the dipsogenic action of intravenous angiotensin II is counteracted by the rise in blood pressure.


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