Spontaneous glomerular deposition of immunoglobulins for ACE (Angiotensin Converting Enzyme) induces spontaneous nephropathy in diabetogenic rats

We first discovered autoantibodies to ACE (angiotensin converting enzyme) in patients with type 2 diabetes mellitus^1^. The antibodies were positive for 64.5% of the patients with diabetes and were positive in 83.3% in the early stage of clinical diabetic nephropathy. In addition, in genetically diabetogenic OLETF (Otsuka Long-Evans Tokushima Fatty) rats^2^, one of the characteristics of which strain is spontaneous nephropathy resembling those of human type 2 diabetes, and in control LETO rats^2^, immunization with rabbit lung ACE developed glomerulopathy similar to that seen in diabetics^3^. Also, in normal New Zealand white rabbits, immunization with the rabbit lung ACE induced glomerular changes similar to those seen in diabetic nephropathy^3^. In this study, renal tissues identical to those examined in research of diabetic nephropathy by PAS staining and electron microscope in preceding study^3^, were examined by immunostaining methods, only to prove that the diabetic glomerular changes may occur by immunization with ACE, not by non-specific responses to ACE, in non-diabetogenic rats and rabbits

Clinical Performance of a Salivary Amylase Activity Monitor During Hemodialysis Treatment

The hemodialysis procedure is thought to be a physical stressor in the majority of hemodialyzed patients. Previous studies suggest that elevated salivary amylase level may correlate with increased plasma norepinephrine level under psychological and physical stress conditions. In this study, we investigated biological stress reactivity during hemodialysis treatment using salivary amylase activity as a biomarker. Seven patients (male/female = 5/2, age: 67.7+/−5.9 years) who had been receiving regular 4 h hemodialysis were recruited. Salivary amylase activity was measured using a portable analyzer every hour during the hemodialysis session. Salivary amylase activity was shown to be relatively stable and constant throughout hemodialysis, whereas there were significant changes in systolic blood pressure and pulse rate associated with blood volume reduction. Our results show that hemodialysis treatment per se dose not affect salivary amylase activity

3H-Spiroperidol (Spiperone) Binding Sites in Rat Adrenal Glomerulosa Cells

3H-spiperone, a dopaminergic antagonist, was used to study binding sites in rat adrenal glomerulosa membrane. The equilibrium dissociation constant (Kd) and binding capacity for 3H-spiperone binding were 2.2 nM and 268 fmol/mg protein, respectively. Determination of the Kd by kinetic studies provided a value of 2.6 nM, which corresponded closely to the Kd estimated by equilibrium studies. In a study of the subcellular distribution of dopamine receptors in adrenal glomerulosa cells, 3H-spiperone binding activity at the interface of density 1.14 to 1.16 accounted for 60% of the total activity in all fractions. These dopaminergic binding sites in adrenal glomerulosa cells may modulate aldosterone secretion induced by antidopaminergic agents

A Radioimmunoassay for Rat Serum Corticosterone

A reliable radioimmunoassay for rat serum corticosterone has been developed. 25 μ1 of diluted serum (1:100) was assayed with a specific antiserum raised against corticosterone-21-hemisuccinate conjugated to bovine serum albumin. The within-assay and between-assay coefficients of variation were 7.1% and 13.9%, respectively. The mean serum corticosterone concentration was 65.3±6.0 ng/ml (n=10). The corticosterone level increased to 208.4 ±23.7 ng/ml after ACTH administration, and was suppressed to the limit of assay sensitivity after dexamethasone administration

Structural basis for high selectivity of a rice silicon channel Lsi1

Silicon (Si), the most abundant mineral element in the earth’s crust, is taken up by plant roots in the form of silicic acid through Low silicon rice 1 (Lsi1). Lsi1 belongs to the Nodulin 26-like intrinsic protein subfamily in aquaporin and shows high selectivity for silicic acid. To uncover the structural basis for this high selectivity, here we show the crystal structure of the rice Lsi1 at a resolution of 1.8 Å. The structure reveals transmembrane helical orientations different from other aquaporins, characterized by a unique, widely opened, and hydrophilic selectivity filter (SF) composed of five residues. Our structural, functional, and theoretical investigations provide a solid structural basis for the Si uptake mechanism in plants, which will contribute to secure and sustainable rice production by manipulating Lsi1 selectivity for different metalloids

Steroidogenesis in Isolated Adrenal Cells of Rat

A reliable and reproducible system for the isolation of rat adrenal cells was developed, using 0.25% trypsin for cell dispersion. The suspending cell in Krebs-Ringer bicarbonate buffer containing 0.2% glucose and 0.5% bovine serum albumin was incubated for 120 minutes at 37℃ under 95% 02 and 5% C02. Corticosterone production induced by synthetic 1-24ACTH showed a dose-related increase in decapsular cells. The precision of the inter-experiment of corticosterone production was 5.0% (average coefficients of variation)