PubMed Health⌕ Search

Biomedical subjects

T I Gottheiner

Publications and source records attributed to T I Gottheiner.

5 recordsLinked to original sources

Acquired cystic disease of the end-stage kidney.

The development of multiple cysts in the previously noncystic chronically diseased kidneys of patients undergoing long-term dialysis appears to be associated with spontaneous renal bleeding and benign and malignant renal tumors. Two cases of acquired cystic disease with renal hemorrhage and adenocarcinoma are presented; metastases occurred in one patient and the other had bilateral carcinoma requiring bilateral nephrectomy. Combined data from 13 studies indicate acquired cystic disease occurs in one third of patients undergoing maintenance hemodialysis and is associated with adenocarcinoma in 4 percent of cases. Four cases of metastases and five deaths linked to acquired cystic disease have been reported. Eight of 24 patients with acquired cystic disease and clinical manifestations of renal bleeding had renal adenocarcinoma. Autopsy series indicate tumors associated with acquired cystic disease are usually benign but commonly bilateral and multiple. Cystic transformation of the end-stage kidney is more frequent after several years of hemodialysis. It is suggested that patients receiving dialysis treatments for more than three years have a baseline radiologic examination of the kidneys so that subsequent problems can be more easily identified and evaluated.

Aged↗

Amino acids enhance renal tubular absorption of the los-molecular-weight proteins insulin and growth hormone.

The effect of amino acids(AA) on the tubular absorption of low-molecular-weight (LMW) proteins was studied in isolated rat kidneys. Kidneys were perfused with an albumin-electrolyte solution that contained insulin or human growth hormone (hGH) and, unless otherwise stated, the following L-amino acids: glycine, isoleucine, serine, alanine, methionine, proline, arginine, and aspartic acid. In kidneys perfused without AA, fractional urinary insulin clearance (FCi) averaged 7.4 +/- 1.54%, whereas in the presence of multiple AA the FCi was significantly lower (0.68 +/- 0.2%, P less than 0.01). Addition of glycine or alpha-aminoisobutyric acid (AIB) alone also reduced the FCi significantly (1.79 +/- 0.66 and 1.59 +/-1.06%, respectively). By contrast, perfusion with the other AA individually did not alter the FCi. The fractional urinary hGH clearance was also significantly lower in kidneys perfused with multiple AA (0.94 +/- 0.47%) than in those perfused without AA (9.07 +/- 1.2%). We conclude that tubular absorption of filtered insulin and hGH is enhanced by the presence of AA. The mechanism is unclear, but enhancement of insulin absorption can be produced by glycine and AIB alone. This raises the possibility of a link between the absorption of insulin and the glycine and AIB shared transport system, but excludes a primary metabolic effect because AIB is nonmetabolizable.

Absorption↗

Removal and excretion of immunoreactive rat growth hormone by the isolated kidney.

The renal uptake of immunoreactive rat growth hormone (rGH), molecular weight 21,500 daltons, was examined in the isolated perfused rat kidney to determine whether peritubular removal of a protein greater than 12,000 daltons occurs and to assess the functional characteristics of renal GH uptake. Organ clearance of rGH (OCGH) in control kidneys was 1,039 +/- 99 microliters/min and was unaffected by an excess of insulin but markedly depressed by col (10 degrees C( and KCN. Although glomerular filtration rate (GFR) did not differ significantly from OCGH in the control rats, we suspected that filtration could not account for all the rGH removed because of glomerular protein sieving. However, GFR was significantly less than OCGH with cold and KCN treatment, indicating the occurrence of peritubular removal. In nonfiltering kidneys, rGH removal exceeded that of [14C]inulin (P less than 0.05), demonstrating peritubular rGH removal. Tubular absorption of rGH was unaffected by insulin but markedly depressed by cold and KCN. We conclude that rGH is removed from the renal circulation mainly by the glomerular filtration-tubular absorptive pathway, but, in addition, as with smaller proteins, that peritubular removal occurs.

Animals↗