Response of deep nephrons and the terminal collecting duct to a reduction in renal mass.

Juxtamedullary (JM) nephron and collecting duct function was studied after a two-thirds reduction in renal mass in the young rat. The glomerular filtration rate of JM nephrons was twofold greater in the remnant kidney (RK) group than in controls, but this increase was proportional to the increase measured in surface nephrons. Despite an increase in absolute reabsorption, delivery of sodium and water to the end of the proximal tubule of superficial nephrons and to the bend of Henle's loop of JM nephrons was increased.

Reticuloendothelial and mesangial function in murine immune complex glomerulonephritis.

The function of the mesangial and reticuloendothelial system was evaluated in normal mice and in mice with nephritis induced by lymphocytic choriomeningitis (LCM) virus infection. Heat-aggregated human immunoglobulin (AlgG) and colloidal carbon served as traceable materials which could be detected in animals' blood and tissues. LCM virus-infected proteinuric (LCM-P) mice, as compared to normal mice or LCM-infected nonproteinuric (LCM) mice, had greater accumulation of AIgG in their glomeruli at all times of examination following i.

Deep nephron function after release of acute unilateral ureteral obstruction in the young rat.

The effects of acute unilateral ureteral obstruction (UUO) of 18 h duration on deep nephron function was evaluated in 14 weanling rats with the technique of micropuncture. After release of UUO, 3.4 +/- 0.

Cholinergic agents inhibit sodium transport across the isolated toad bladder.

Acetylcholine and carbamylcholine (carbachol) inhibited sodium transport across the toad bladder. This effect was blocked by atropine. Carbachol increased the uptake of 45Ca by isolated toad bladder epithelial cells.

Hyperkalemia after renal transplantation. Occurrence in a patient with insulin-dependent diabetes.

An insulin-dependent diabetic patient received a renal transplant from a living related donor without evidence of rejection. In the posttransplant period, his serum potassium concentration (3.7 to 6.

Adenylate cyclase of human parathyroid gland.

Experiments were performed on a particulate fraction from human parathyroid glands. A high activity of adenylate cyclase was detected which was linear with time and protein concentration. The enzyme had an optimum pH in the range of 7-8 and a Km for ATP of 0.

Selective uptake of the synthetic amino terminal fragment of bovine parathyroid hormone by isolated perfused bone.

Studies from our laboratory have shown that the metabolic clearance rate of carboxy terminal immunoreactive parathyroid hormone (i-PTH) can be accounted for by extraction of i-PTH by liver and kidney. In contrast, there was no demonstrable hepatic uptake of the synthetic amino terminal bovine PTH fragment (syn b-PTH 1-34) and the kidney accounted for only 45% of the metabolic clearance rate of amino terminal i-PTH. This suggested that another major site, presumably bone, played a role in the metabolism of syn b-PTH 1-34.

The role of calcium in renal gluconeogenesis: studies using ionophore A23187.

The divalent cation ionophore A23187 was found to increase glucose production from alpha-ketoglutarate, glutamine, succinate, and lactate but not from glycerol in isolated rat renal cortical tubules at external Ca++ concentrations of 0.1 mM. At an external Ca++ concentration of 1.

Degradation of parathyroid hormone and fragment production by the isolated perfused dog kidney. The effect of glomerular filtration rate and perfusate CA++ concentrations.

The renal degradation of intact bovine parathyroid hormone (b-PTH 1-84) was studied with the isolated perfused dog kidney. Disappearance of b-PTH 1-84 from the perfusate occurred concomitantly with the appearance of smaller molecular weight forms of immunoreactive parathyroid hormone (PTH). These smaller molecular weight PTH fragments included both carboxyl and amino terminal regions of the PTH peptide.

Effects of acute bilateral ureteral obstruction on deep nephron and terminal collecting duct function in the young rat.

The effects of acute bilateral ureteral obstruction (BUO) of 18-h duration on deep nephron and collecting duct function were studied by micropuncture in 11 weanling rats. After release of BUO glomerular filtration rate was reduced (178+/-15 vs. 1,343+/-119 mul/min per g kidney weight in shams), while urine flow was increased averaging 17.

T-cell deficiency in immune complex glomerulonephritis.

Mice chronically infected with the virus of lymphocytic choriomeningitis (LCM) develop immune complex glomerulonephritis. Others have shown that adoptive immunization of these mice by the i.p.

Effects of insulin, ADH, and cyclic AMP on sodium transport in the toad bladder.

These studies further define the mechanisms by which insulin stimulates Na transport in the toad bladder. Serosal but not mucosal addition of insulin, 100-1,000 mU/ml, stimulated short-circuit current (SCC) by 25-50%. The initial rise in SCC occurred at 5 min and the peak response at 15-25 min.

Effects of ionophore A23187 on base-line and vasopressin-stimulated sodium transport in the toad bladder.

The cation specific ionophore A23187 (Io) is a useful tool for studying the role of intracellular Ca++ (Ca++)i in physiologic processes. The present studies explore the role of (Ca++)i on Na transport in the toad bladder. Scraped bladder cells exposed to 1 muM Io for 60 min took up 100% more 45Ca than control cells.