Effects of a reversible ‘nephrectomy’ on renal sympathetic activity and blood pressure in the rat

Recordati, G; Zorzoli, Federica; Zanchetti, Alberto

doi:10.1097/00004872-200018090-00014

Cited by 7 publications

(5 citation statements)

References 36 publications

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“…Furthermore, urinary catecholamine levels were double in 11b-Hsd2 K/K mice (Bailey et al 2008). Thus, the increased blood pressure following UNX might be the consequence of both an enhanced renal sodium retention and an increased sympathetic drive, a hypothesis of interest as it is conceivable that the dampened renal efferent nerve activity to the contralateral kidney after UNX modulates the 11b-HSD activity in the remaining kidney (Recordati et al 2000).…”

Section: Discussionmentioning

confidence: 99%

Uninephrectomy reduces 11β-hydroxysteroid dehydrogenase type 1 and type 2 concomitantly with an increase in blood pressure in rats

Lauterburg¹,

Escher²,

Dick³

et al. 2012

Journal of Endocrinology

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Renal allograft donors are at risk of developing hypertension. Here, we hypothesized that this risk is at least in part explained by an enhanced intracellular availability of 11b-hydroxyglucocorticoids due to an increased 11b-hydroxysteroid dehydrogenase type 1 enzyme (11b-HSD1), an intracellular prereceptor activator of biologically inactive 11-ketocorticosteroids in the liver, and/or a diminished 11b-hydroxysteroid dehydrogenase type 2 (11b-HSD2), an inactivator of 11b-hydroxyglucocorticoids in the kidney. To test this hypothesis, uninephrectomized (UNX) (nZ9) and sham-operated (nZ10) adult SpragueDawley rats were investigated. Mean arterial blood pressure and heart rate were measured continuously by telemetry for 6 days in week 5 after UNX. The mRNA of 11b-Hsd1 and 11b-Hsd2 in liver and kidney tissues were assessed by RT-PCR and the 11b-HSD activities were directly quantified in their corresponding tissues by determining the ratios of (tetrahydrocorticosteroneC5a-tetrahydrocorticosterone)/ tetrahydrodehydrocorticosterone ((THBC5a-THB)/THA) and of corticosterone/dehydrocorticosterone (B/A) by gas chromatography-mass spectrometry. The apparent total body activities of 11b-HSD1 and 11b-HSD2 were estimated using the urinary and plasma ratios of (THBC5a-THB)/THA and B/A. Mean arterial blood pressure was increased after UNX when compared with sham operation. Hepatic mRNA content of 11b-Hsd1 and hepatic, plasma, and urinary ratios of (THBC5a-THB)/THA were decreased after UNX, indicating diminished access of glucocorticoids to its receptors. In renal tissue, 11b-Hsd2 mRNA was reduced and B/A ratios measured in kidney, plasma, and urine were increased, indicating reduced 11b-HSD2 activity and enhanced access of glucocorticoids to mineralocorticoid receptors. Both 11b-HSD1 and 11b-HSD2 are downregulated after UNX in rats, a constellation considered to induce hypertension.

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Section: Discussionmentioning

confidence: 99%

Uninephrectomy reduces 11β-hydroxysteroid dehydrogenase type 1 and type 2 concomitantly with an increase in blood pressure in rats

Lauterburg¹,

Escher²,

Dick³

et al. 2012

Journal of Endocrinology

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“…Environmental stimuli favoring a sensitization process of postganglionic sympathetic neurons (Jänig et al, 1982;Blumberg and Jänig, 1983) similar to that described for the gill withdrawal reflex of aplysia and hippocampal networks (Kandel, 2001) may reinforce the sympathetic tone, induce a neurogenic hyperkinetic state (Julius, 1996;Julius and Majahalme, 2000) and increase blood pressure variability (Frattola et al, 1993). Positive sympathetic reflexes (Malliani and Montano, 2002) sympathetic -renin -angiotensin interactions (Recordati et al, 2000), faulty noradrenaline reuptake into the cardiac sympathetic nerves (Rumantir et al, 2000;Esler et al, 2001) and sympathetic cotransmitter control of blood vessels (Burnstock, 2002) may also come into play. The beneficial effects in hypertensive patients of aerobic muscle exercise, low metabolic energy intake, low Na+ diet, decreased stress level and mental relaxation, which all positively contribute to increase parasympathetic cardiac and circulatory control and lower sympathetic activity and arterial blood pressure, may favor the point of view that primary hypertension may be caused by a pathophysiological imbalance of the autonomic nervous system regulatory function.…”

Section: Perspectivesmentioning

confidence: 94%

A thermodynamic model of the sympathetic and parasympathetic nervous systems

Recordati¹

2003

Autonomic Neuroscience

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In light of the nonequilibrium thermodynamics by I. Prigogine, the autonomic nervous system as a whole may be viewed as a dissipative structure progressively assembled in the course of evolution, plastically and rhythmically interfaced between forebrain, internal and external environments, to regulate energy, matter and information exchanges. In the present paper, this hypothesis is further pursued to verify whether the two main divisions of the autonomic nervous system, the sympathetic and parasympathetic systems, may support different types of exchange with the external environment. Previous data from hypothalamic stimulation experiments, studies of locus coeruleus function and available data on behavioral functional organization indicate that (1) tight engagement with the external environment, (2) high level of energy mobilization and utilization and (3) information mainly related to exteroceptive sensory stimulation characterize a behavioral prevalence of sympathoadrenal activation. On the other hand, (1) disengagement from the external environment, (2) low levels of internal energy and (3) dominance of proprioceptive information characterize a behavioral prevalence of vagal tone. Behavioral matter exchanges such as feeding, drinking, micturition and defecation are equally absent at the extreme of sympathoadrenal and vagally driven behaviors. The autonomic nervous system as a whole is genetically determined, but the sympathoadrenal system has been mainly designed to organize the visceral apparatus for an action to be performed by the biological system in the external environment and to deal with the novelty of task and of the environment, while the functional role of the parasympathetic is to prepare the visceral apparatus for an action to be performed by the biological system on itself, for recovery and self-protection (homeostasis), and is reinforced by repetition of phylo- and ontogenetically determined patterns. The available clinical data further support this interpretation indicating that an increased sympathetic and a decreased vagal tone may represent a consistent risk factor for cardiovascular diseases.

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“…The stimuli from the internal compartment may originate either from the visceral apparatus as visceral sensory information (Malliani et al, 1973;Recordati et al, 1976Recordati et al, , 1980Furness et al, 1999), from humoral in#uences (hormones from endocrine organs, gastrointestinal tract, cytokines, etc.) and from higher brain centers as emotional and stressful stimuli, socio-cultural and cognitive experiences (Henry, 1997;Folkow, 2000a, b).…”

Section: Some General Principles About the Vns Functional Rolementioning

confidence: 99%

“…We know, furthermore, that in the course of evolution, functions, characterized by a positive interaction between stimulus and response have also emerged, such as the relation between sympathetic activity and energy balance (Young & Landsberg, 1977;Szekely, 2000), the somatosympathetic re#exes (Sato et al, 1997), and viscero-visceral spinal sympathetic re#exes (Beacham & Perl, 1964;Malliani, 2000) and the positive feedback interactions between angiotensin and the sympathetic nervous system (Zimmerman et al, 1984;Zanchetti, 1986;Recordati et al, 2000). Di!erent structures with heterogenous functional meanings may therefore coexist.…”

Section: Perspectivesmentioning

confidence: 99%

The Visceral Nervous System and its Environments

Recordati

2002

Journal of Theoretical Biology

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Starting from the observation of the relationships of the biological system with its environments and of the genetically determined neuronal properties of plasticity and rhythmicity, it is possible to propose a new hypothesis about the functional role and organization of the visceral nervous system based on the physical model of the Dissipative Structure by I. Prigogine. The similarily between the visceral nervous system function and this model is supported by the following observations: (1) The visceral nervous system is a complex system, composed of many interacting units, which works away from thermodynamic equilibrium; (2) the functional organization of the nervous system is strongly dependent on internal and external environmental stimuli; (3) it is characterized by the presence of rhythms and periodic behaviors and (4) the internal order of the system is maintained in the continuous interplay between function, structure and #uctuations. On the basis of the present hypothesis, a few general principles can be formulated: (1) the higher brain centers, the #uid matrix and the external world, are the visceral nervous system natural environments; (2) with which it is plastically interfaced as a thermodynamic dissipative structure; (3) its main functional role is to regulate, distribute and maintain ordered exchanges of matter, energy and information between these environments. The present is a general interpretation of the operations of the visceral nervous system as a whole. In the frame of this interpretation the hypotheses so far formulated, including the homeostatic theory, can be viewed as the description of discrete and complementary aspects of the visceral nervous system functions. Academic Press

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Effects of a reversible ‘nephrectomy’ on renal sympathetic activity and blood pressure in the rat

Cited by 7 publications

References 36 publications

Uninephrectomy reduces 11β-hydroxysteroid dehydrogenase type 1 and type 2 concomitantly with an increase in blood pressure in rats

Uninephrectomy reduces 11β-hydroxysteroid dehydrogenase type 1 and type 2 concomitantly with an increase in blood pressure in rats

A thermodynamic model of the sympathetic and parasympathetic nervous systems

The Visceral Nervous System and its Environments

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