scholarly journals Fetal Undernutrition Programming, Sympathetic Nerve Activity, and Arterial Hypertension Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Vinícius Schiavinatto Mariano ◽  
Patrícia Aline Boer ◽  
José Antônio Rocha Gontijo

A wealth of evidence showed that low birth weight is associated with environmental disruption during gestation, triggering embryotic or fetal adaptations and increasing the susceptibility of progeny to non-communicable diseases, including metabolic and cardiovascular diseases, obesity, and arterial hypertension. In addition, dietary disturbance during pregnancy in animal models has highlighted mechanisms that involve the genesis of arterial hypertension, particularly severe maternal low-protein intake (LP). Functional studies demonstrated that maternal low-protein intake leads to the renal decrease of sodium excretion and the dysfunction of the renin-angiotensin-aldosterone system signaling of LP offspring. The antinatriuretic effect is accentuated by a reduced number of nephron units and glomerulosclerosis, which are critical in establishing arterial hypertension phenotype. Also, in this way, studies have shown that the overactivity of the central and peripheral sympathetic nervous system occurs due to reduced sensory (afferent) renal nerve activity. As a result of this reciprocal and abnormal renorenal reflex, there is an enhanced tubule sodium proximal sodium reabsorption, which, at least in part, contributes directly to arterial hypertension development in some of the programmed models. A recent study has observed that significant changes in adrenal medulla secretion could be involved in the pathophysiological process of increasing blood pressure. Thus, this review aims to compile studies that link the central and peripheral sympathetic system activity mechanisms on water and salt handle and blood pressure control in the maternal protein-restricted offspring. Besides, these pathophysiological mechanisms mainly may involve the modulation of neurokinins and catecholamines pathways.

1980 ◽  
Vol 58 (5) ◽  
pp. 477-483 ◽  
Author(s):  
D. R. Wilson ◽  
M. Cusimano ◽  
U. Honrath

The role of the renal nerves in the altered sodium reabsorption which occurs during increased ureteral pressure was studied using clearance techniques in anaesthetized rats undergoing diuresis induced by isotonic saline infusion. In rats with a sham denervated kidney, an ipsilateral increase in ureteral pressure to 20 cm H2O resulted in a marked and significant decrease in sodium and water excretion, increased fractional sodium reabsorption, and increased urine osmolality with no significant change in glomerular filtration rate. A similar significant ipsilateral increase in tubular reabsorption of sodium occurred in rats with chronically denervated kidneys during increased ureteral pressure. The changes in tubular reabsorption were rapidly reversible after return of ureteral pressure to normal. These experiments indicate that enhanced tubular reabsorption of sodium during an ipsilateral increase in ureteral pressure is not mediated by increased renal nerve activity. During the antinatriuresis of increased ureteral pressure there was a decrease in the fractional reabsorption of sodium from the opposite normal kidney. The role of the renal nerves in this compensatory change in function in the opposite kidney was studied in two further groups of animals. The renal response to a contralateral increase in ureteral pressure was similar in denervated and sham-denervated kidneys. The results indicate that altered renal nerve activity, through ipsilateral or contralateral renorenal reflexes, is not responsible for the changes in tubular reabsorption of sodium which occur during increased ureteral pressure induced by partial ureteral obstruction.


2006 ◽  
Vol 111 (6) ◽  
pp. 365-372 ◽  
Author(s):  
Wolfgang Lieb ◽  
Juliane Bolbrinker ◽  
Angela Döring ◽  
Hans-Werner Hense ◽  
Jeanette Erdmann ◽  
...  

A polymorphism in the cytochrome P450 3A CYP3A5 enzyme has been implicated in BP (blood pressure) control and arterial hypertension. Carriers of the CYP3A5*1 allele had high, whereas homozygous carriers of the CYP3A5*3 allele exhibit low, CYP3A5 expression in the kidney, where CYP3A5 represents the major CYP3A enzyme. The aim of the present study was to investigate the association of the CYP3A5*1 allele with BP, arterial hypertension, LVM [(left ventricular) mass] and LV geometry in a large Caucasian-population-based cohort. We compared BP, LVM and the prevalence of hypertension between carriers (CYP3A5*1/*1 and CYP3A5*1/*3 genotypes) and non-carriers (CYP3A5*3/*3 genotype) of the CYP3A5*1 allele in the echocardiographic substudy of the third MONICA (MONItoring trends and determinants in CArdiovascular disease) Augsburg survey. After exclusion of 269 individuals who were taking antihypertensive medication, 530 women and 554 men were available for analysis, revealing allele frequencies of 5.8 and 94.2% for the CYP3A5*1 and CYP3A5*3 alleles respectively. Overall, the presence of the CYP3A5*1 allele exhibited no effect on systolic or diastolic BP in either gender. One-third of the individuals in this cohort were hypertensive (BP ≥140/90 mmHg), and the genotype distribution between normotensive and hypertensive individuals revealed no association between CYP3A5*1 and hypertension after adjustment for age, BMI and gender (odds ratio, 1.02; P=0.92). Moreover, no effect of CYP3A5*1 on LVM, thickness of the septal and posterior wall and LV end-diastolic diameter was found. We conclude that CYP3A5*1 exhibits no significant effect on BP, LVM and LV geometry in the KORA/MONICA echocardiographic substudy.


Physiology ◽  
2021 ◽  
Vol 36 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Jessica R. Ivy ◽  
Matthew A. Bailey

Blood pressure follows a daily rhythm, dipping during nocturnal sleep in humans. Attenuation of this dip (nondipping) is associated with increased risk of cardiovascular disease. Renal control of sodium homeostasis is essential for long-term blood pressure control. Sodium reabsorption and excretion have rhythms that rely on predictive/circadian as well as reactive adaptations. We explore how these rhythms might contribute to blood pressure rhythm in health and disease.


1983 ◽  
Vol 244 (1) ◽  
pp. F64-F69 ◽  
Author(s):  
C. R. Silva-Netto ◽  
R. H. Jackson ◽  
R. E. Colindres

We investigated possible mechanisms for the natriuresis seen after injection of the cholinergic drug carbamylcholine chloride (carbachol) into the lateral hypothalamus of conscious rats. In unrestrained rats injection of 1 microgram of carbachol in 1 microliter of 0.15 M NaCl solution through a permanently implanted cannula produced a significant natriuresis and kaliuresis. Injection of vehicle produced no changes. The same animals were then subjected to bilateral renal denervation (n = 13) or sham denervation (n = 13) and injected with the same solutions 1 wk later. Carbachol injection produced a natriuresis (P less than 0.0001) and a kaliuresis (P less than 0.01) in all animals studied. Both responses were of a magnitude similar to the responses seen before denervation. We studied other rats while awake but restrained, which permitted the performance of clearance studies and blood pressure measurements. Injection of carbachol produced diuresis, natriuresis, and kaliuresis in all rats, with no change in p-aminohippurate clearance and only transient change in inulin clearance. An increase in blood pressure occurred in some but not all rats. The response in rats with bilaterally denervated kidneys (n = 7) was similar to that of rats with innervated kidneys (n = 5). The natriuresis seen after cholinergic stimulation of the hypothalamus in conscious rats is not primarily mediated by inhibition of renal nerve activity and can be dissociated from changes in blood pressure, glomerular filtration rate, and renal plasma flow.


1997 ◽  
Vol 272 (2) ◽  
pp. H776-H784 ◽  
Author(s):  
H. M. Stauss ◽  
D. A. Morgan ◽  
K. E. Anderson ◽  
M. P. Massett ◽  
K. C. Kregel

To investigate the effects of hyperthermia and aging on baroreceptor-heart rate reflex sensitivity (BRS), cardiovascular parameters were recorded during a progressive rise in core temperature in conscious mature and senescent Fischer 344 rats. BRS was calculated from spontaneous changes in blood pressure and interbeat interval. Low- (LF, 0.01-0.20 Hz) and mid- (MF, 0.2-0.5 Hz) frequency blood pressure power were also determined. In both age groups, hyperthermia caused an increase in blood pressure, renal resistance, and LF but no changes in renal nerve activity, whereas a tachycardia was only observed in the older rats. Increases in BRS (0.80 +/- 0.14 vs. 1.72 +/- 0.34 ms/mmHg, P < 0.05) and MF (3.10 +/- 0.55 vs. 7.81 +/- 1.89 mmHg2, P < 0.05) and a positive correlation between BRS and MF (r = 0.50, P < 0.01) were observed with heating in mature but not senescent rats. These results indicate that LF, which increased with elevated core temperature, may be modulated by thermal stimuli. The augmented BRS in the mature group may contribute to the hemodynamic adjustments that occur with hyperthermia, whereas the lack of an increase in BRS during heat stress in the senescent group suggests that baroreceptor reflex modulation is impaired with aging. The positive correlation between BRS and MF in mature rats, together with the lack of an increase in renal sympathetic nerve activity, indicates that MF may reflect the modulating influence of the efferent sympathetic portion of the baroreceptor reflex loop on arterial blood pressure rather than merely the activity of the peripheral sympathetic nervous system.


2007 ◽  
Vol 71 (3) ◽  
pp. 245-251 ◽  
Author(s):  
V. Bellizzi ◽  
B.R. Di Iorio ◽  
L. De Nicola ◽  
R. Minutolo ◽  
P. Zamboli ◽  
...  

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