Vasopressin stimulation of NaCl transport in the medullary thick ascending limb of Henle's loop is decreased in aging mice

1991 ◽  
Vol 419 (3-4) ◽  
pp. 327-331 ◽  
Author(s):  
A. Di Stefano ◽  
M. Wittner ◽  
B. Corman
2011 ◽  
Vol 301 (5) ◽  
pp. F979-F996 ◽  
Author(s):  
Aurélie Edwards ◽  
Anita T. Layton

We expanded our region-based model of water and solute exchanges in the rat outer medulla to incorporate the transport of nitric oxide (NO) and superoxide (O2−) and to examine the impact of NO-O2− interactions on medullary thick ascending limb (mTAL) NaCl reabsorption and oxygen (O2) consumption, under both physiological and pathological conditions. Our results suggest that NaCl transport and the concentrating capacity of the outer medulla are substantially modulated by basal levels of NO and O2−. Moreover, the effect of each solute on NaCl reabsorption cannot be considered in isolation, given the feedback loops resulting from three-way interactions between O2, NO, and O2−. Notwithstanding vasoactive effects, our model predicts that in the absence of O2−-mediated stimulation of NaCl active transport, the outer medullary concentrating capacity (evaluated as the collecting duct fluid osmolality at the outer-inner medullary junction) would be ∼40% lower. Conversely, without NO-induced inhibition of NaCl active transport, the outer medullary concentrating capacity would increase by ∼70%, but only if that anaerobic metabolism can provide up to half the maximal energy requirements of the outer medulla. The model suggests that in addition to scavenging NO, O2− modulates NO levels indirectly via its stimulation of mTAL metabolism, leading to reduction of O2 as a substrate for NO. When O2− levels are raised 10-fold, as in hypertensive animals, mTAL NaCl reabsorption is significantly enhanced, even as the inefficient use of O2 exacerbates hypoxia in the outer medulla. Conversely, an increase in tubular and vascular flows is predicted to substantially reduce mTAL NaCl reabsorption. In conclusion, our model suggests that the complex interactions between NO, O2−, and O2 significantly impact the O2 balance and NaCl reabsorption in the outer medulla.


2016 ◽  
Vol 469 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Nina Himmerkus ◽  
Allein Plain ◽  
Rita D. Marques ◽  
Svenja R. Sonntag ◽  
Alexander Paliege ◽  
...  

1990 ◽  
Vol 127 (3) ◽  
pp. 377-382 ◽  
Author(s):  
J. A. Charlton ◽  
P. H. Baylis

ABSTRACT Previous studies have indicated that ornithine decarboxylase (ODC) may be involved in the stimulation of Na+/K+-ATPase activity by arginine vasopressin (AVP) in the rat renal medullary thick ascending limb of Henle's loop. The present study was aimed at establishing the role of the polyamines, the conversion products of ODC activity, in the stimulation of Na+/K+-ATPase by AVP. Using cytochemical methods, we have demonstrated an increase in Na+/K+-ATPase activity after stimulation with putrescine, spermidine and spermine (each 1 mmol/l) for 2·5,2 and 1·5 min respectively. The specific inhibitors of spermidine and spermine synthase, bis-cyclohexylammonium sulphate and N-alkylated-1,3-diaminopropane respectively, inhibited the stimulation of Na+/K+-ATPase by AVP, this inhibition being reversed by spermine. These findings suggest that polyamines are involved in the stimulus-response coupling of the hormone-mediated response. Journal of Endocrinology (1990) 127, 377–382


1990 ◽  
Vol 127 (2) ◽  
pp. 213-216 ◽  
Author(s):  
J. A. Charlton ◽  
P. H. Baylis

ABSTRACT In previous studies, we have demonstrated that 1–10 fmol arginine vasopressin (AVP)/l maximally stimulates the activity of the enzyme Na+/K+-ATPase in the rat renal medullary thick ascending limb (MTAL) of Henle's loop after 4 or 10 min of stimulation when measured using a cytochemical bioassay. We have tested the hypothesis that this stimulation is mediated by the V2 receptor in the MTAL. A cytochemical bioassay was used to investigate the effect of specific V1 and V2/V1 antagonists and a synthetic V2 agonist [1-deamino,8-d-arginine]-vasopressin (dDAVP), on the activity of Na+/K+-ATPase. There was no effect of the V1 antagonist (1 fmol-1 μmol/l) in inhibiting the activity of Na+/K+-ATPase stimulated by 1 fmol AVP/l. In contrast, 100 pmol of the V2/V1 antagonist/l significantly (P < 0·001) inhibited the stimulation of Na+/K+-ATPase activity by 1 fmol AVP/l from 55·5±4·3 (s.e.m.) to 31·9±1·6 mean integrated extinction (MIE) after 4 min of stimulation and from 67·0±3·2 to 36·9±0·7 MIE after 10 min of stimulation. Similarly, the stimulation of Na+/K+-ATPase by 10 fmol dDAVP/l was inhibited by the V2/V1 antagonist from 55·1±1·0 to 26·1±0·5 MIE after 4 min of stimulation. We conclude that the stimulation of Na+/K+-ATPase by AVP is mediated by the V2 receptor in the rat renal MTAL. Journal of Endocrinology (1990) 127, 213–216


1984 ◽  
Vol 247 (5) ◽  
pp. F784-F792 ◽  
Author(s):  
R. M. Culpepper ◽  
T. E. Andreoli

Prostaglandin E2 (PGE2) inhibits the ADH-stimulated components of the lumen-positive transepithelial voltage (Ve) and of net chloride absorption (JnetCl) in the isolated microperfused mouse medullary thick ascending limb of Henle (mTALH), presumably by interfering with the ADH-dependent intracellular accumulation of cAMP. These experiments examined the interactions of PGE2 with two nonhormonal stimulators of adenylate cyclase--cholera toxin and forskolin--in an attempt to evaluate the means by which PGE2 inhibits ADH-stimulated transport in these mTALH segments. Forskolin (FSK) stimulated Ve in the mTALH with half-maximal stimulation at 1.4 X 10(-7) M FSK. PGE2 had no effect on FSK stimulation of Ve; 10(-6) M FSK reversed completely the PGE2 inhibition of ADH-stimulated Ve. A low concentration of cholera toxin, 5 X 10(-13) M, stimulated Ve and JnetCl in the mTALH; 10(-6) M PGE2 inhibited the stimulation by cholera toxin; and 10(-6) M FSK reversed the PGE2 inhibition of both Ve and JnetCl in cholera toxin-stimulated mTALH. A higher concentration of cholera toxin, 10(-10) M, stimulated Ve and JnetCl to values identical to those seen with maximal concentrations of ADH, but PGE2 did not inhibit the increments in either Ve or JnetCl produced by 10(-10) M cholera toxin. PGE2 appears to inhibit ADH stimulation of NaCl transport in mTALH by an action distal to hormone-receptor interactions yet proximal to the catalytic subunit of adenylate cyclase.


2016 ◽  
Vol 310 (4) ◽  
pp. F294-F299 ◽  
Author(s):  
Michel Baum

Angiotensin II (ANG II) is secreted by the proximal tubule resulting in a luminal concentration that is 100- to 1,000-fold greater than that in the blood. Luminal ANG II has been shown to stimulate sodium transport in the proximal tubule and distal nephron. Surprisingly, luminal ANG II inhibits NaCl transport in the medullary thick ascending limb (mTAL), a nephron segment responsible for a significant amount of NaCl absorption from the glomerular ultrafiltrate. We confirmed that addition of 10−8 M ANG II to the lumen inhibited mTAL chloride transport (220 ± 19 to 165 ± 25 pmol·mm−1·min−1, P < 0.01) and examined whether an interaction with basolateral norepinephrine existed to simulate the in vivo condition of an innervated tubule. We found that in the presence of a 10−6 M norepinephrine bath, luminal ANG II stimulated mTAL chloride transport from 298 ± 18 to 364 ± 42 pmol·mm−1·min−1 ( P < 0.05). Stimulation of chloride transport by luminal ANG II was also observed with 10−3 M bath dibutyryl cAMP in the bathing solution and bath isoproterenol. A bath of 10−5 H-89 blocked the stimulation of chloride transport by norepinephrine and prevented the effect of luminal ANG II to either stimulate or inhibit chloride transport. Bath phentolamine, an α-adrenergic agonist, also prevented the decrease in mTAL chloride transport by luminal ANG II. Thus luminal ANG II increases chloride transport with basolateral norepinephrine; an effect likely mediated by stimulation of cAMP. Alpha-1 adrenergic stimulation prevents the inhibition of chloride transport by luminal ANG II.


1989 ◽  
Vol 120 (2) ◽  
pp. 195-199 ◽  
Author(s):  
J. A. Charlton ◽  
P. H. Baylis

ABSTRACT The effect of arginine vasopressin (AVP) on rat renal ornithine decarboxylase (ODC) activity was investigated by a cytochemical technique optimized for use in the medullary thick ascending limb of Henle's loop (mTAL). Stimulation of ODC activity by AVP was confined to the mTAL. Peaks in enzyme activity in cultured rat renal segments occurred after tissue had been exposed to AVP for 3 or 8 min and these times of maximal stimulation did not change with the concentration of AVP. There was a dose-dependent response in ODC activity over the AVP concentration range 0·01–10 fmol/l. The ODC response to AVP was totally blocked by specific antiserum to AVP and reduced by 70% with the specific inhibitor to ODC, difluoromethyl ornithine. Journal of Endocrinology (1989) 120, 195–199


1994 ◽  
Vol 46 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Carolyn M. Macica ◽  
Bruno A. Escalante ◽  
Michael S. Conners ◽  
Nicholas R. Ferreri

1995 ◽  
Vol 268 (5) ◽  
pp. F940-F947 ◽  
Author(s):  
G. Wolf ◽  
F. N. Ziyadeh ◽  
U. Helmchen ◽  
G. Zahner ◽  
R. Schroeder ◽  
...  

A murine SV40-transformed renal epithelial cell line derived from medullary thick ascending limb of Henle's loop (MTAL) was established and characterized by morphology, antigen expression, and biochemical criteria. These MTAL cells express a single class of high-affinity receptors for angiotensin II (ANG II) and transcripts for the AT1 subtype of ANG II receptors. ANG II, in a dose-dependent manner, induced proliferation of MTAL cells. This observation is in striking contrast to syngeneic proximal tubular cells in which it was previously shown that the peptide induced cellular hypertrophy and slightly inhibited proliferation [G. Wolf and E. G. Neilson. Am. J. Physiol. 259 (Renal Fluid Electrolyte Physiol. 28: F768-F777, 1990]. The AT1-receptor antagonist losartan (10(-6) M), but not an AT2-receptor antagonist, blocked the mitogenic effects of ANG II in MTAL cells. Coincubation of quiescent MTAL cells with ANG II and 5% fetal calf serum further increased proliferation compared with cells grown only in serum. In contrast to proximal tubular cells, ANG II failed to induce transforming growth factor-beta 1 mRNA and protein synthesis in MTAL cells. Our data collectively suggest that ANG II is a mitogen for MTAL cells in vitro. Therefore, epithelial cells derived from different parts of the nephron, even when transformed with SV40 virus and while under cell culture conditions, exhibit a distinct pattern of growth behavior after stimulation with ANG II.


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