Combined prenatal and postnatal protein restriction influences adult kidney structure, function, and arterial pressure

2007 ◽  
Vol 292 (1) ◽  
pp. R462-R469 ◽  
Author(s):  
Chantal C. Hoppe ◽  
Roger G. Evans ◽  
Karen M. Moritz ◽  
Luise A. Cullen-McEwen ◽  
Sharyn M. Fitzgerald ◽  
...  

The effects of prenatal protein restriction on adult renal and cardiovascular function have been studied in considerable detail. However, little is known about the effects of life-long protein restriction, a common condition in the developing world. Therefore, we determined in rats the effects of combined pre- and postnatal protein restriction on adult arterial pressure and renal function and responses to increased dietary sodium. Nephron number was also determined. Male Sprague-Dawley rats were born to mothers fed a low [8% (wt/wt), LP] or normal [20% (wt/wt), NP] isocaloric protein diet throughout pregnancy and maintained on these diets after birth. At postnatal day 135, nephron number, mean arterial pressure (MAP), and renal function were determined. A high-NaCl [8.0% (wt/wt), high-salt] diet was fed to a subset of rats from weaning. MAP was less in LP than in NP rats (120 ± 2 vs. 128 ± 2 mmHg, P < 0.05) and was not significantly altered by increased salt intake. Nephron number was 31% less in LP than in NP rats ( P < 0.001). The volume of individual glomeruli was also less in LP than in NP rats, as were calculated effective renal plasma flow and glomerular filtration rate. Glomerular filtration rate, but not effective renal plasma flow, appeared to be increased by high salt intake, particularly in LP rats. In conclusion, protein restriction induced a severe nephron deficit, but MAP was lower, rather than higher, in protein-restricted than in control rats in adulthood. These findings indicate that the postnatal environment plays a key role in determining the outcomes of developmental programming.

1971 ◽  
Vol 10 (01) ◽  
pp. 16-24
Author(s):  
J. Fog Pedersen ◽  
M. Fog Pedersen ◽  
Paul Madsen

SummaryAn accurate catheter-free technique for clinical determination simultaneouslyof glomerular filtration rate and effective renal plasma flow by means of radioisotopes has been developed. The renal function is estimated by the amount of radioisotopes necessary to maintain a constant concentration in the patient’s blood. The infusion pumps are steered by a feedback system, the pumps being automatically turned on when the radiation measured over the patient’s head falls below a certain preset level and turned off when this level is again readied. 131I-iodopyracet was used for the estimation of effective renal plasma flow and125I-iothalamate estimation of the glomerular filtration rate. These clearances were compared to the conventional bladder clearances and good correlation was found between these two clearance methods (correlation coefficients 0.97 and.90 respectively). The advantages and disadvantages of this new clearance technique are discussed.


2017 ◽  
Vol 5 (6) ◽  
pp. e13202 ◽  
Author(s):  
Mariano E. Ibarra ◽  
Maria F. Albertoni Borghese ◽  
Mónica P. Majowicz ◽  
María C. Ortiz ◽  
Fabián Loidl ◽  
...  

1990 ◽  
Vol 258 (3) ◽  
pp. F643-F648
Author(s):  
M. Nakagawa ◽  
J. M. Stewart ◽  
R. J. Vavrek ◽  
A. Nasjletti

We contrasted the effects of D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-DPhe-Thi-Arg-TFA (kinin receptor antagonist), of aprotinin (kallikrein inhibitor), and of combined treatment with captopril (kininase II inhibitor) and phosphoramidon (neutral endopeptidase 24.11 inhibitor) on renal function of rats with and without 14-day deoxycorticosterone pretreatment (DOC, 25 mg.kg-1.wk-1 sc). Neither the kinin antagonist nor aprotinin affected renal function in rats with and without DOC pretreatment. Combined treatment with captopril and phosphoramidon caused in rats with and without DOC pretreatment augmentation (P less than 0.05) of kinin excretion (50-64%), glomerular filtration rate (12-11%), and sodium excretion (46-48%). In DOC-pretreated rats undergoing infusion of captopril and phosphoramidon, the superimposed administration of either the kinin antagonist or aprotinin caused the lowering of renal plasma flow, glomerular filtration rate, and sodium excretion. These effects of the kinin antagonist and aprotinin in rats infused with kininase inhibitors may be the consequence of blockade, respectively, of the renal actions and synthesis of kinins that, when in excess, elicit renal vasodilation and increase glomerular filtration rate and sodium excretion. Collectively, these observations suggest regulatory influence of kinins during conditions featuring increased renal kinin levels.


1957 ◽  
Vol 188 (2) ◽  
pp. 367-370 ◽  
Author(s):  
L. H. Smith ◽  
W. R. Boss

In a study of the direct effects of irradiation on the renal function of rats whose exteriorized kidneys were exposed to massive doses of x-rays, significant augmentation of the urine flow was observed 28 days after 2500 r. On the 7th day after 2500, 3000 and 4000 r the urine flow was slightly above that of control rats. The glomerular filtration rate was enhanced on the 7th day after 2500 and 3000 r. Conversely, 28 days after these x-ray doses the filtration rate was slightly below the control values. In the 4000-r, 28-day group, the glomerular filtration rate was 43% below that of the controls. No significant changes in the renal plasma flow occurred on the 7th day after 2500, 3000 and 4000 r. An insignificant increase in the renal plasma flow was noted 28 days after 2500 and 3000 r. On the 28th day after 4000 r, however, the renal plasma flow was 51% below that of the controls. We concluded that both augmentation and depression of renal function were the result of the direct action of x-rays on the kidneys. The results also suggest that renal failure resulting from direct irradiation damage to the kidneys is not a major factor that contributes to deaths occurring within 7 days after the exposure of rats to 4000 r or less of whole-body x-rays.


1993 ◽  
Vol 264 (1) ◽  
pp. R222-R226 ◽  
Author(s):  
D. M. Pollock ◽  
T. J. Opgenorth

Experiments were designed to examine the role of endothelin (ET) receptors, specifically ETA receptors, in mediating the renal vasoconstrictor effects of ET-1 in anesthetized Sprague-Dawley rats. Intravenous infusion of ET-1 at 25 pmol.kg-1 x min-1 for 60 min produced a significant increase in mean arterial pressure (20 +/- 7%) and decreases in renal plasma flow (-60 +/- 6%) and glomerular filtration rate (-47 +/- 6%). Renal vascular resistance was significantly increased from 17 +/- 1 mmHg.ml-1 x min.g kidney wt during control period to 54 +/- 11 mmHg.ml-1 x min.g kidney wt during the experimental period. A second group of rats was infused with both ET-1 and the specific ETA receptor antagonist BQ-123 (0.1 mg.kg-1 x min-1). ET-1-induced increases in mean arterial pressure were completely blocked by BQ-123 (the average change was -7 +/- 4%). However, the renal vasoconstrictor effects of ET-1 were not affected by the antagonist, since renal plasma flow and glomerular filtration rate were again significantly reduced (-54 +/- 4 and -56 +/- 6%, respectively). Once again, renal vascular resistance was significantly increased from 16 +/- 2 mmHg.ml-1 x min.g kidney wt during the control period to 33 +/- 5 mmHg.ml-1 x min.g kidney wt during the experimental period. In a third group, infusion of BQ-123 alone produced a significant decline in mean arterial pressure (-13 +/- 2%), with no significant changes in renal plasma flow or glomerular filtration rate, thus producing a significant decrease in renal vascular resistance (15 +/- 1 vs. 11 +/- 2 mmHg.ml-1 x min.g kidney wt).(ABSTRACT TRUNCATED AT 250 WORDS)


1993 ◽  
Vol 71 (10-11) ◽  
pp. 848-853
Author(s):  
José M. López-Novoa ◽  
Inmaculada Montañés

The aim of this study was to evaluate the effects of the two enantiomers of a new dihydropyridine, S12967 and S12968, on rat renal function. Male Wistar rats were injected intravenously with saline, S12967, or S12968 (0.1, 0.3, or 1 mg/kg body weight). Urinary flow, glomerular filtration rate, renal plasma flow, urinary sodium, potassium, and calcium excretions, mean arterial pressure, and renal vascular resistance were determined before and every 30 min up to 180 min after administration of the tested substance. The levogyre enantiomer S12968, at a dose of 0.3 mg/kg, induced a 4-fold increase in urinary sodium excretion, without significant or with minor changes in glomerular filtration rate, renal plasma flow, or renal blood flow. The hypotensive effect was small and nonsignificant. At 1 mg/kg, S12968 caused a profound hypotensive effect that impaired the renal function, induced marked oliguria, and decreased glomerular filtration rate and renal blood flow to almost negligible values. The dextrogyre enantiomer S12967 had much less effect on renal function. These data showing specific stereoselective renal effects are in agreement with pharmacological studies that have demonstrated that S12968 possesses a higher affinity for the dihydropyridine-binding site than its dextrogyre enantiomer, S12967.Key words: Ca channel antagonists, dihydropyridine, glomerular filtration rate, renal blood flow, natriuresis, mean arterial pressure.


1989 ◽  
Vol 30 (4) ◽  
pp. 383-389 ◽  
Author(s):  
A. Nygren ◽  
H. R. Ulfendahl ◽  
A. Fasching

The effects of a slow intravenous injection of contrast media (CM) on renal function and haemodynamics were investigated in euvolaemic and dehydrated rats. Iodine-equivalent doses (1600 mg I/kg body weight) of ioxithalamate, ioxaglate, iopamidol and iohexol were used. Glomerular filtration rate (GFR) and renal plasma flow (RPF) were assessed with clearance techniques. In euvolaemic rats no statistically significant decrease in GFR or RPF was found after CM injections. In the dehydrated rats the changes in GFR were more pronounced and this was significantly decreased in the ioxithalamate and iopamidol groups while RPF was still not decreased. This study indicates that dehydration potentiates adverse effects of CM on GFR and that there may be differences between the effects of low-osmolar and high-osmolar CM on GFR and also between different low-osmolar CM.


1949 ◽  
Vol 90 (6) ◽  
pp. 511-524 ◽  
Author(s):  
J. Stamler ◽  
L. N. Katz ◽  
S. Rodbard

Evidence is presented on the occurrence of spontaneous hypertension in dogs. All dogs with spontaneous hypertension exhibited normal renal plasma flow and glomerular filtration rate. Clearances on nephrogenic hypertensive dogs revealed that some exhibited normal kidney function, while others had significant depression of renal plasma flow and glomerular filtration rate. In the latter, the filtration fraction may or may not be elevated. Serial renal clearances were done at intervals on 3 dogs with spontaneous hypertension during their 3rd year of known hypertension. They exhibited no tendency to develop impaired renal function in the face of prolonged benign hypertension. Serial renal clearances on nephrogenic hypertensive dogs revealed no tendency for kidney function to become progressively impaired. This was true, whether the immediate postoperative clearance values were normal or depressed. It was also true regardless of the duration of the hypertension. It is suggested that mechanisms other than elevated blood pressure per se operate to produce progressive kidney damage and impairment of renal function. No tendency was revealed over the course of a year or more for the kidney function to improve in Goldblatt dogs exhibiting depressed clearances immediately postoperatively. This is interpreted as evidence against the postoperative development in persistently hypertensive Goldblatt dogs of a renal collateral circulation sufficient to augment significantly effective renal blood flow. Pathological studies on 2 dogs with spontaneous hypertension revealed slight to moderate chronic focal lesions in the kidneys, and bilateral adrenal cortical adenomatous hyperplasia. Both lesions may have no pathogenetic significance. In accord with previous observations, autopsies on 3 Goldblatt dogs revealed minimal renal changes in one, and unilateral kidney atrophy with contralateral hypertrophy in the 2 others. The adrenals were normal. In general, data on renal clearances showed correlation with postmortem kidney findings. However, normal renal clearances are found in the presence of anatomically abnormal kidneys. The findings in canine spontaneous and nephrogenic hypertension are compared and contrasted with data obtained in human essential hypertension. Pathogenetic relationships are discussed.


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