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J J Gehrig

Publications and source records attributed to J J Gehrig.

5 recordsLinked to original sources
PubMed1988

Effect of long-term, alternate day feeding on renal function in aging conscious rats.

To examine the renal effects of lifelong intermittent feeding, we performed clearance and pathologic studies in 86 week old, awake male Sprague-Dawley rats fed on alternate days (N = 9) or ad libitum (N = 8) since the age of four weeks. Alternate day-fed rats were studied on both feeding and fasting days, and the values averaged. In the alternate day group the clearances of inulin (Cinulin) and PAH (CPAH), factored by body wt, were higher by 23% and 27%, respectively (P less than 0.05); albumin excretion (UalbV) was two orders of magnitude lower (P less than 0.001) and the percentage of glomeruli with lesions was eightfold lower (P less than 0.02) than in the ad libitum-fed group. The fractional clearances of neutral dextrans ranging in radii from 20 A to 42 A did not differ between the two groups. Compared to a previously published study of 30 week old, alternate day-fed rats, values for Cinulin and CPAH were similar while UalbV was higher (P less than 0.025) in the 86 week old alternate day-fed rats. Cinulin, however, was lower (P less than 0.005) while UalbV was much higher (P less than 0.001) in 86 week old, ad libitum-fed rats than in 30 week old, ad libitum-fed rats. The results indicate that long-term alternate day feeding preserves glomerular filtration rate (GFR) and renal plasma flow (RPF), while glomerular permselectivity is not completely preserved, as evidenced by an increase in microalbuminuria in aging awake male rats. Conversely, ad libitum feeding results in a significant decline in GFR and probably in RPF, in association with massive albuminuria and segmental glomerular sclerosis.

Aging↗
PubMed1986

Effect of intermittent feeding on renal hemodynamics in conscious rats.

The hemodynamic influences of many forms of dietary restriction have not been studied in the conscious rat. To examine the effect of one regimen of dietary restriction, alternate-day feeding, on renal hemodynamics, we performed 56 clearance studies in 20 unanesthetized, previously catheterized male Sprague-Dawley rats at mean age 30 wk. Group 1 rats (n = 10) were given standard chow only on alternate days for 25 wk and then studied after feeding and after fasting days, whereas group 2 rats (n = 10) were fed ad libitum during the same period and then studied randomly. In group 1, glomerular filtration rate (GFR, clearance of inulin) and renal blood flow [RBF, clearance of PAH/(1 - hematocrit)] increased 23 and 19%, respectively, after feeding days compared with fasting days (GFR, 4.25 vs. 3.47 ml/min, P less than 0.005; RBF, 22.2 vs. 18.6 ml/min, P less than 0.025). After feeding, mean arterial pressure and plasma protein concentration were unchanged, hematocrit increased slightly, and fractional excretion of sodium rose from 0.23 to 0.57%. Both GFR and RBF averaged 31% less in group 1 than in group 2 but, when factored by body weight, the differences were abolished. The results indicate that alternate-day feeding causes substantial oscillations in GFR and RBF in healthy awake rats through mechanisms unlikely to involve changes in extracellular fluid volume alone and limits GFR and RBF to average values markedly lower than those observed for larger ad libitum-fed rats of the same age.

Animals↗
PubMed1985

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↗