Effects of thyrotrophin-releasing hormone on renal function in the rat

1987 ◽  
Vol 113 (3) ◽  
pp. 445-448 ◽  
Author(s):  
H. O. Garland
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Vascular System ◽  
Renal Plasma Flow ◽  
Acute Effects ◽  
Thyrotrophin Releasing Hormone ◽  
Anaesthetized Rats ◽  
Renal Vascular

ABSTRACT Standard renal clearance techniques were used to investigate the acute effects of TRH on kidney function in anaesthetized rats. A significant reduction in salt and water outputs, glomerular filtration rate and renal plasma flow was produced within 10 min of infusion of 12 μg TRH over 30 min. The rapidity of the response may suggest a direct effect of TRH on the renal vascular system. J. Endocr. (1987) 113,445–448

Clinical Renal Function Testing by External Double Isotope Monitoring Technique

1971 ◽  
Vol 10 (01) ◽  
pp. 16-24
Author(s):  
J. Fog Pedersen ◽  
M. Fog Pedersen ◽  
Paul Madsen
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Effective Renal Plasma Flow ◽  
Advantages And Disadvantages

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.

RENAL FUNCTION AND KIDNEY SIZE FOLLOWING HYPOPHYSECTOMY IN MAN

1965 ◽  
Vol 48 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Thomas Falkheden ◽  
Ingmar Wickbom
Keyword(s):  
Renal Function ◽  
Diabetic Retinopathy ◽  
Glomerular Filtration Rate ◽  
Plasma Flow ◽  
Mammary Carcinoma ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Kidney Weight ◽  
Kidney Size ◽  
Before And After

ABSTRACT Measurements of glomerular filtration rate (GFR) and renal plasma flow (RPF) were performed in close connection with roentgenographic estimation of kidney size, before and after hypophysectomy, in 10 patients (four cases of metastatic mammary carcinoma, five cases of diabetic retinopathy and one case of acromegaly). Hypophysectomy was regularly followed by a decrease in GFR and RPF. In most cases, a reduction in the roentgenographic kidney size was also observed. However, the changes in the roentgenographic kidney size and calculated kidney weight after hypophysectomy were smaller and occurred at a slower rate than the alterations in GFR and RPF. The results favour the view that, primarily, the decrease in GFR and RPF following hypophysectomy is essentially functional rather than due to a reduced kidney mass.

Dynamics of ascites formation in rats with experimental cirrhosis

1980 ◽  
Vol 238 (5) ◽  
pp. F353-F357 ◽  
Author(s):  
J. M. Lopez-Novoa ◽  
M. A. Rengel ◽  
L. Hernando
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Hepatic Cirrhosis ◽  
Renal Plasma Flow ◽  
Sodium Balance ◽  
Partial Removal ◽  
Experimental Cirrhosis ◽  
Ascites Formation

Renal function, sodium balance, and ascites formation were observed during induction in rats of experimental cirrhosis. The same variables were studied after partial removal of the ascites in rats with experimental cirrhosis. Glomerular filtration rate (GFR) and effective renal plasma flow (RPF) did not change during hepatic cirrhosis development. Positive sodium balance significantly higher than that observed in controls preceded the appearance of ascites for a period of about 2 wk. When the ascites was removed, GFR, RPF and positive Na balance did not change if Na intake remained constant. Ascites reformation rate was largely dependent on sodium balance. These data strongly support the "overflow" theory of ascites formation and are difficult to reconcile with the classical "underfilling" theory.

Effects of a kinin antagonist on renal function in rats

1990 ◽  
Vol 258 (3) ◽  
pp. F643-F648
Author(s):  
M. Nakagawa ◽  
J. M. Stewart ◽  
R. J. Vavrek ◽  
A. Nasjletti
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Combined Treatment ◽  
Neutral Endopeptidase ◽  
Kinin Receptor

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.

Effects of X-Irradiation on Renal Function of Rats

1957 ◽  
Vol 188 (2) ◽  
pp. 367-370 ◽  
Author(s):  
L. H. Smith ◽  
W. R. Boss
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Urine Flow ◽  
Whole Body ◽  
Irradiation Damage ◽  
X Rays

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.

Evidence for endothelin-induced renal vasoconstriction independent of ETA receptor activation

1993 ◽  
Vol 264 (1) ◽  
pp. R222-R226 ◽  
Author(s):  
D. M. Pollock ◽  
T. J. Opgenorth
Keyword(s):  
Glomerular Filtration Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Glomerular Filtration ◽  
Vascular Resistance ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Renal Vascular Resistance ◽  
Renal Vascular

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)

Effects of High- and Low-Osmolar Contrast Media on Renal Plasma Flow and Glomerular Filtration Rate in Euvolaemic and Dehydrated Rats

1989 ◽  
Vol 30 (4) ◽  
pp. 383-389 ◽  
Author(s):  
A. Nygren ◽  
H. R. Ulfendahl ◽  
A. Fasching
Keyword(s):  
Renal Function ◽  
Body Weight ◽  
Glomerular Filtration Rate ◽  
Adverse Effects ◽  
Contrast Media ◽  
Glomerular Filtration ◽  
Intravenous Injection ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow

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.

scholarly journals SERIAL RENAL CLEARANCES IN DOGS WITH NEPHROGENIC AND SPONTANEOUS HYPERTENSION

1949 ◽  
Vol 90 (6) ◽  
pp. 511-524 ◽  
Author(s):  
J. Stamler ◽  
L. N. Katz ◽  
S. Rodbard
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Kidney Function ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Spontaneous Hypertension ◽  
Focal Lesions ◽  
Renal Clearances

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.

Changes in Renal Function in Acute Experimental Pancreatitis in Rats: A Therapeutic Role for Somatostatin

1993 ◽  
Vol 85 (5) ◽  
pp. 615-621 ◽  
Author(s):  
M. González-Rubio ◽  
C. García-Escribano ◽  
M. L. Díez-Marqués ◽  
I. Arribas ◽  
P. Martínez-Onsurbe ◽  
...  
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Plasma Flow ◽  
Bile Salts ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Experimental Pancreatitis ◽  
Biliary Duct ◽  
Therapeutic Role ◽  
Severe Pancreatitis

1. The present study was designed to determine the changes in renal function in two models of experimental pancreatitis in rats, in an attempt to assess the possible pathogenic role of reactive oxygen species and to elucidate a possible therapeutic role for somatostatin. 2. Mild pancreatitis was induced by low blockade of the biliary duct and severe pancreatitis was evoked by retrograde infusion of bile salts. Renal function was studied by clearance techniques in rats with pancreatitis, treated or not treated with somatostatin. Plasma and glomerular malonyldialdehyde levels were measured by the thiobarbituric acid method. 3. Renal function did not change in rats with low blockade of the biliary duct, but animals receiving a retrograde infusion of bile salts showed a significant decrease in glomerular filtration rate and renal plasma flow with respect to sham-operated animals. 4. Plasma malonyldialdehyde levels increased significantly in rats treated with bile salts with respect to control animals, whereas no changes were detected in glomerular malonyldialdehyde levels. Thus, the renal dysfunction does not seem to be related to an increased production of reactive oxygen metabolites at the glomerular level. 5. Somatostatin infusion significantly improved renal function in rats with severe pancreatitis (retrograde infusion of bile salts) by increasing glomerular filtration rate, renal plasma flow and filtration fraction. These results support a possible therapeutic role for somatostatin in the renal dysfunction associated with the severe forms of pancreatitis.

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