scholarly journals Concentration of phosphoribosyl pyrophosphate in renal hypertrophy. Contrasting effects of early diabetes and unilateral nephrectomy

1986 ◽  
Vol 239 (1) ◽  
pp. 241-244 ◽  
Author(s):  
S Kunjara ◽  
M Sochor ◽  
A L Greenbaum ◽  
P McLean
Keyword(s):  
Nucleic Acid ◽  
Unilateral Nephrectomy ◽  
Phosphoribosyl Pyrophosphate ◽  
Renal Hypertrophy ◽  
Early Diabetes ◽  
Nucleotide Synthesis ◽  
Contralateral Kidney ◽  
Increment Of Growth ◽  
Renal Enlargement

Studies were made of the renal phosphoribosyl pyrophosphate (PPRibP) content and PPRibP synthetase (EC 2.7.6.1) activity in rats diabetic for 5, 14 or 20 days, or unilaterally nephrectomized (UN) for 5 days, and in doubly lesioned animals. Approximately equal degrees of renal enlargement were found after 5 days diabetes or 5 days UN. In the doubly lesioned animals the increment of growth was additive. Unilateral nephrectomy of 5 days duration, in contrast with diabetes, had no effect on the PPRibP content of the contralateral kidney, nor did it modify the renal PPRibP content when performed on animals diabetic for 5, 14 or 20 days. The activity of PPRibP synthetase was unaffected by diabetes, UN or diabetes +UN. The results pinpoint a stage of nucleotide synthesis which is differentially affected by the two stimuli, in line with evidence for differences in regulation of nucleic acid turnover in the two conditions.

scholarly journals Renal hypertrophy in experimental diabetes. The activity of the ‘de novo’ and salvage pathways of purine [corrected] synthesis

1988 ◽  
Vol 249 (3) ◽  
pp. 911-914 ◽  
Author(s):  
S Kunjara ◽  
S J Beardsley ◽  
A L Greenbaum
Keyword(s):  
Nucleic Acids ◽  
De Novo ◽  
Experimental Diabetes ◽  
Salvage Pathway ◽  
Phosphoribosyl Pyrophosphate ◽  
Renal Hypertrophy ◽  
Early Diabetes ◽  
Nucleotide Synthesis ◽  
Main Route ◽  
Salvage Pathways

Measurements were made of the activity of phosphoribosyl pyrophosphate amidotransferase (PPRibP-At, EC 2.4.2.14) and of adenine (APRT, EC 2.4.2.7) and hypoxanthine (HPRT, EC 2.4.2.8) phosphoribosyltransferases, representing the ‘de novo’ and salvage pathways respectively. PPRibP-At activity increased within 3 days of diabetes, whereas APRT and HPRT increased later. Incorporation of [14C]formate and of [8-14C]adenine into the nucleic acids of kidney slices showed that formate was incorporated earlier, and to a greater extent, than was adenine. These results indicate that, although the ‘de novo’ pathway for nucleotide synthesis is the main route in early diabetes, the salvage pathway assumes greater importance at later stages.

Primary response gene expression in renal hypertrophy and hyperplasia: evidence for different growth initiation processes

1991 ◽  
Vol 260 (6) ◽  
pp. F823-F827 ◽  
Author(s):  
D. A. Kujubu ◽  
J. T. Norman ◽  
H. R. Herschman ◽  
L. G. Fine
Keyword(s):  
Folic Acid ◽  
Cellular Response ◽  
Primary Response ◽  
Unilateral Nephrectomy ◽  
Transcriptional Level ◽  
Sham Operation ◽  
Mrna Levels ◽  
Renal Hypertrophy ◽  
Hypertrophic Response ◽  
Contralateral Kidney

Unilateral nephrectomy is followed by compensatory renal hypertrophy, a response in which the cells of the contralateral kidney increase in size and protein content without synthesizing DNA or dividing. To determine whether the earliest phase of the hypertrophic response has features similar to mitogenic or differentiation responses, we have characterized the expression of several primary-response genes, the 12-O-tetradecanoylphorbol-13-acetate (TPA)-inducible sequences (TIS) genes, which are rapidly and transiently induced in the absence of intervening protein synthesis, in a variety of mitogenic and differentiation cell systems. TIS gene induction was studied in the contralateral kidney of uninephrectomized and sham-operated mice, as well as in the kidneys of mice in which renal cell proliferation was induced by folic acid injection. Induction of TIS 1, TIS 8, and TIS 11 mRNA levels following folic acid administration peaked at 2 to 4 h and persisted up to 6 to 12 h after mitogenic stimulation. In contrast, a qualitatively different pattern was observed after both uninephrectomy and sham operation; a short-lived increase (up to 1 h) in mRNA levels occurred for the three TIS genes. This pattern was qualitatively similar to that observed in the sham-operated animals. We conclude that renal hypertrophy induced by unilateral nephrectomy is a distinct cellular response, distinguishable at the earliest transcriptional level from a mitogenic response and from the responses that characterize several pathways of cell differentiation.

Uridine and cytidine nucleotide synthesis in renal hypertrophy: Biochemical differences in response to the growth stimulus of diabetes and unilateral nephrectomy

1992 ◽  
Vol 47 (2) ◽  
pp. 168-180 ◽  
Author(s):  
Sirilaksana Kunjara ◽  
Milena Sochor ◽  
Murad Ali ◽  
Michael Bennett ◽  
A.Leslie Greenbaum ◽  
...  
Keyword(s):  
Unilateral Nephrectomy ◽  
Renal Hypertrophy ◽  
Nucleotide Synthesis

scholarly journals THE PATHOGENESIS OF HYPERTENSION INDUCED BY RENAL CONSTRICTION

1950 ◽  
Vol 92 (1) ◽  
pp. 59-76 ◽  
Author(s):  
L. J. Rather
Keyword(s):  
Blood Pressure ◽  
Young Male ◽  
The Other ◽  
Unilateral Nephrectomy ◽  
Albino Rats ◽  
Renal Hypertrophy ◽  
Ether Anesthesia ◽  
Frequency Distributions ◽  
Contralateral Kidney ◽  
Blood Pressures

Blood pressures were determined on forty-two young male albino rats and a basal level established. The rats were then divided into four groups and subjected to one of the following operations: (a) unilateral nephrectomy with exposure and handling of the opposite kidney; (b) unilateral nephrectomy and constriction of the remaining kidney with a silk figure-of-eight ligature; (c) unilateral renal constriction with a silk figure-of-eight ligature, the other kidney being left intact after exposure and handling; (d) unilateral nephrectomy and removal of the poles of the contralateral kidney (three-quarters nephrectomy). The animals were followed for 50 days, during which blood pressures were measured on twenty occasions, then killed by exsanguination under ether anesthesia. The organs were weighed according to a standardized procedure and studied histologically. Individual determinations of serum creatinine and of the hematocrit levels were made. Mean lines and frequency distributions of blood pressure were subjected to statistical analysis. A definitely significant increase in blood pressure developed in the group subjected to operation (b) within 4 days postoperative. In none of the other groups did hypertension develop. Analysis of the individual renal weights and creatinine levels indicates the independence of the development of hypertension from the total mass of functioning renal tissue. Nor is it dependent on the prevention of renal hypertrophy or the presence of fibrous perinephritis. The effect is probably due to the production of a disturbance of hemodynamics or tissue tension with the liberation of a pressor substance by the injured kidney.

scholarly journals THE DEGREE OF COMPENSATORY RENAL HYPERTROPHY FOLLOWING UNILATERAL NEPHRECTOMY

1938 ◽  
Vol 67 (4) ◽  
pp. 515-519 ◽  
Author(s):  
Lois L. MacKay ◽  
T. Addis ◽  
Eaton M. MacKay
Keyword(s):  
Protein Intake ◽  
Compensatory Hypertrophy ◽  
Unilateral Nephrectomy ◽  
Albino Rats ◽  
Renal Hypertrophy ◽  
Young Rats ◽  
Compensatory Renal Hypertrophy ◽  
Old Rats

Compensatory hypertrophy of the kidney in albino rats is increased by an increase in the protein intake. The effect is greater in old rats than young rats. Successive increases in the protein intake are followed by a reduction in the increase in the degree of compensatory renal hypertrophy.

scholarly journals Inositol lipid signalling occurs in brush-border membranes during initiation of compensatory renal growth in the rat

1993 ◽  
Vol 295 (2) ◽  
pp. 599-605 ◽  
Author(s):  
H Banfić ◽  
M Vuica ◽  
M Knotek ◽  
S Moslavac ◽  
N Divecha
Keyword(s):  
Brush Border ◽  
Plasma Membranes ◽  
Rat Kidney ◽  
Unilateral Nephrectomy ◽  
Kidney Cortex ◽  
Compensatory Renal Growth ◽  
Rat Kidney Cortex ◽  
Contralateral Kidney ◽  
Inositol Lipids ◽  
Stimulation Of

Using highly specific mass assays, concentrations of inositol lipids and 1,2-diacylglycerol (DAG) were determined in plasma membranes isolated from rat kidney cortex. Significantly higher concentrations of inositol lipids were determined in brush-border (BBM) than in basal-lateral (BLM) plasma membranes, although DAG concentrations were similar in both. After unilateral nephrectomy, a decrease in PtdIns(4,5)P2 and PtdIns4P, with a concomitant increase in DAG and translocation of protein kinase C (PKC), were observed in BBM but not in BLM isolated from the remaining kidney. On the other hand, stimulation of renal cortical slices with insulin-like growth factor II (IGF-II) or phenylephrine caused similar effects in BLM but not in BBM. Stimulation of phospholipase C activity with translocation of PKC only to BBM in one kidney was also induced by occlusion of blood flow through the contralateral kidney for 15 min. At 30 min after the occlusion was removed and reflow established, DAG concentration and the amount of PKC in BBM returned to control values. These results suggest that an early signal after unilateral nephrectomy is transmitted to cells through BBM and can be switched on and off by blood occlusion and reflow through the contralateral kidney, while hormonal signals caused by IGF-II and phenylephrine are transmitted to cells through BLM.

scholarly journals Acute unilateral nephrectomy elicits a specific increase in plasma of peptides derived from the N-terminal region of proopiomelanocortin.

1992 ◽  
Vol 3 (5) ◽  
pp. 1105-1112
Author(s):  
C Qiu ◽  
J P Valentin ◽  
X W Chen ◽  
E Wiedemann ◽  
M H Humphreys
Keyword(s):  
Natriuretic Peptide ◽  
Plasma Concentrations ◽  
Terminal Region ◽  
Unilateral Nephrectomy ◽  
Contralateral Kidney ◽  
Control Value ◽  
Melanocyte Stimulating Hormone ◽  
Reflex Pathways ◽  
Group I ◽  
Specific Increase

Acute unilateral nephrectomy (AUN) causes natriuresis from the contralateral kidney through neurohumoral reflex pathways that involve an increase in the plasma of peptides derived from the N-terminal region of the adrenocorticotropic hormone (ACTH)/beta-endorphin precursor proopiomelanocortin (POMC). To determine the specificity of these humoral changes, the concentrations in plasma of ACTH and two peptides arising from the N-terminal fragment (NTF) of POMC, NTF32-49 and gamma-melanocyte-stimulating hormone (gamma-MSH), and of another natriuretic peptide, atrial natriuretic peptide (ANP), were measured by RIA with highly specific antisera to these epitopes. Group I experiments followed the course of sodium excretion (UNaV) for 120 min after AUN or sham nephrectomy. UNaV more than doubled within 60 min of AUN, and this natriuresis was maintained for the remainder of the experiment, whereas UNaV in sham rats did not change. There was no difference in plasma immunoreactive (ir) ACTH or ir-ANP concentrations between sham and AUN rats 120 min after the procedure, but plasma ir-NTF concentration was double in AUN rats compared with sham (P < 0.03). In Group II experiments, animals were killed 30, 60, 90, or 120 min after AUN and the urinary response related to peptide concentrations in plasma. UNaV rose rapidly after AUN, reaching a maximum value within 45 min that again was double the control value and remained stable for the duration of the experiment, up to 120 min after AUN. There was no significant change in ir-ACTH or ir-ANP at any point after AUN compared with values in sham AUN rats. However, plasma concentrations of both ir-NTF and ir-gamma-MSH were elevated 30 min after AUN and reached values at 120 min that were again double the values in sham rats (P < 0.05 for both).(ABSTRACT TRUNCATED AT 250 WORDS)

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