Rabbit and Human Renotropin are not Epidermal Growth Factor

Memon, Sarfraz; Gongwei, Jiang; Ahmad, Sahrim; Gilbert, Richard; Regan, James; Preuss, Harry G.

doi:10.1016/s0022-5347(17)36344-9

Cited by 1 publication

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To our knowledge, there have only been four previous studies of renotropic activity in human sera following nephrectomy (Yamada et al 1983; Yamamoto et al 1983; Memon, Gongwei, Ahmed, Gilbert, Regan & Preuss, 1993; Garcia Ocana, Ortega, Gonzales‐Garcia, Garcia‐Canton & Esbrit, 1993). Similar to the present investigation, these studies observed maximal stimulation of human PTC thymidine incorporation by post‐nephrectomy sera at approximately day 7, although the degree of peak stimulation varied considerably between 30 % (Memon et al 1993) and 600 % (Yamamoto et al 1983). The latter differences may be explained by patient heterogeneity and by differences in cell density, and therefore in cell‐contact inhibition of proliferation, at the time of serum stimulation (Yamamoto et al 1983).…”

Section: Discussionmentioning

confidence: 99%

“…The major drawbacks of each of these four studies included the use of human PTC cultures established from only one (Yamamoto et al 1983) or two kidneys (Yamada et al 1983; Memon et al 1993), lack of sufficient characterization of cultures to exclude contamination by adventitious cells (e.g. fibroblasts or distal tubular epithelial cells) and the failure to include post‐operative sera from appropriate controls.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Role of insulin‐like growth factor binding proteins in human post‐nephrectomy proximal tubule cells

Johnson

Saunders

Field

et al. 1998

The Journal of Physiology

View full text Add to dashboard Cite

In order to determine the role of the insulin‐like growth factor‐I (IGF‐I)/IGF binding protein (IGFBP) axis in the augmentation of tubule growth and function following reductions in nephron mass, primary cultures of human proximal tubule cells (PTCs) were generated from the histologically normal sections of ten surgically removed kidneys. PTC hypertrophy (cellular protein content), DNA synthesis (thymidine incorporation) and apical sodium‐hydrogen exchange (NHE) activity (ethylisopropylamiloride‐sensitive apical 22Na+ uptake) were measured following 24 h incubation in media supplemented with 10 % pre‐ or post‐nephrectomy sera obtained from these patients. The results were compared with the effects of pre‐ and post‐operative control sera collected from seven patients undergoing retroperitoneal operations not involving removal of renal tissue. Day 1 post‐nephrectomy sera promoted a significant 73 % increase in apical NHE activity, which was accompanied by a significant increase in PTC binding of 125I‐IGF‐I (post‐ vs. pre‐nephrectomy, 163 ± 6 vs. 142 ± 4 fmol (mg protein)−1; P < 0.05). Subsequent post‐nephrectomy sera significantly stimulated PTC protein content and thymidine incorporation, peaking at day 7 (127.7 ± 14.0 and 118.4 ± 9.0 % of pre‐nephrectomy values, respectively; P < 0.05). The growth effects were cell specific, as they were not observed with renal cortical fibroblasts. No change was detected in any of these measured variables following exposure to control sera. Serum IGF‐I and IGFBP‐1 levels did not significantly change over time or between groups. IGFBP‐3 levels progressively decreased in both control and nephrectomized sera from pre‐operative values of 3580 ± 305 and 3360 ± 217 ng ml−1, respectively, to 2670 ± 341 and 2600 ± 347 ng ml−1 at 1 week post‐operation. Serum IGFBP‐2 levels increased to a comparable extent in both controls (day 0 vs. day 7, 2940 ± 1024 vs. 7010 ± 2520 ng ml−1; P < 0.01) and nephrectomized patients (day 0 vs. day 7, 3070 ± 656 vs. 9130 ± 2010 ng ml−1; P < 0.01). The results indicate that nephrectomy engenders the elaboration of one or more humoral factor(s), which promotes increased binding of IGF‐I to PTCs and which may in turn specifically stimulate PTC Na+ transport and growth.

show abstract