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Aims The goal of the study was to evaluate the efficacy of epalrestat, an aldose reductase inhibitor, on diabetic retinopathy and diabetic nephropathy, based on analysis of the results of the Aldose Reductase Inhibitor–Diabetes Complications Trial, a 3-year multicentre comparative clinical trial of conventional therapy (control group) and epalrestat therapy (epalrestat group) in Japanese patients with mild diabetic neuropathy. Methods The subjects of the study were patients enrolled in the Aldose Reductase Inhibitor–Diabetes Complications Trial for whom data for major patient characteristics, severity of diabetic neuropathy at the end of the study and time-courses of diabetic retinopathy and diabetic nephropathy were available (57 and 52 patients from the control and epalrestat groups, respectively). Progression of diabetic retinopathy/nephropathy (a primary endpoint) in relation to major patient characteristics, severity of diabetic neuropathy at the end of the study (assessed from the mean of z-scores in four neurological function tests) and epalrestat treatment were analysed using univariate analysis and multiple logistic regression analysis. Results Progression of diabetic retinopathy/nephropathy was significantly inhibited in the epalrestat group compared with the control group (odds ratio = 0.323, P = 0.014) and was dependent on the severity of diabetic neuropathy at the end of the study (odds ratio = 2.131, P = 0.025). Conclusions Epalrestat prevented progression of diabetic neuropathy and retinopathy/nephropathy. The effect on diabetic retinopathy/nephropathy may have occurred indirectly because of the prevention of progression of diabetic neuropathy, in addition to the inhibitory action of epalrestat on aldose reductase.

Aims The long-term efficacy of epalrestat, an aldose reductase inhibitor, in improving subjective symptoms and nerve function was comprehensively assessed to identify patients with diabetic peripheral neuropathy who responded to epalrestat treatment. Methods Stratified analyses were conducted on data from patients in the Aldose Reductase Inhibitor—Diabetes Complications Trial (ADCT). The ADCT included patients with diabetic peripheral neuropathy, median motor nerve conduction velocity ≥ 40 m/s and with glycated haemoglobin (HbA1c) ≤ 9.0%. Longitudinal data on HbA1c and subjective symptoms of the patients for 3 years were analysed (epalrestat n = 231, control subjects n = 273). Stratified analyses based on background variables (glycaemic control, grades of retinopathy or proteinuria) were performed to examine the relationship between subjective symptoms and nerve function. Multiple logistic regression analyses were conducted. Results Stratified subgroup analyses revealed significantly better efficacy of epalrestat in patients with good glycaemic control and less severe diabetic complications. In the control group, no improvement in nerve function was seen regardless of whether symptomatic benefit was obtained. In the epalrestat group, nerve function deteriorated less or improved in patients whose symptoms improved. The odds ratio of the efficacy of epalrestat vs. control subjects was approximately 2 : 1 (4 : 1 in patients with HbA1c ≤ 7.0%). Conclusion Our results suggest that epalrestat, an aldose reductase inhibitor, will provide a clinically significant means of preventing and treating diabetic neuropathy if used in appropriate patients. Diabet. Med. 25, 818–825 (2008)

OBJECTIVE—We sought to evaluate the long-term efficacy and safety of epalrestat, an aldose reductase inhibitor, on diabetic peripheral neuropathy. RESEARCH DESIGN AND METHODS—Subjects with diabetic neuropathy, median motor nerve conduction velocity (MNCV) ≥40 m/s, and HbA1c ≤9% were enrolled in this open-label, multicenter study and randomized to 150 mg/day epalrestat or a control group. After excluding the withdrawals, 289 (epalrestat group) and 305 (control group) patients were included in the analyses. The primary end point was change from baseline in median MNCV at 3 years. Secondary end points included assessment of other somatic nerve function parameters (minimum F-wave latency [MFWL] of the median motor nerve and vibration perception threshold [VPT]), cardiovascular autonomic nerve function, and subjective symptoms. RESULTS—Over the 3-year period, epalrestat prevented the deterioration of median MNCV, MFWL, and VPT seen in the control group. The between-group difference in change from baseline in median MNCV was 1.6 m/s (P < 0.001). Although a benefit with epalrestat was observed in cardiovascular autonomic nerve function variables, this did not reach statistical significance compared with the control group. Numbness of limbs, sensory abnormality, and cramping improved significantly with epalrestat versus the control group. The effects of epalrestat on median MNCV were most evident in subjects with better glycemic control and with no or mild microangiopathies. CONCLUSIONS—Long-term treatment with epalrestat is well tolerated and can effectively delay the progression of diabetic neuropathy and ameliorate the associated symptoms of the disease, particularly in subjects with good glycemic control and limited microangiopathy.

The addition of Pd into Ni/SiO2 improved the catalytic activity and life for methane decomposition into hydrogen and carbon nanofibers. Thus, Pd-added Ni/SiO2 (denoted as Pd−Ni/SiO2) was characteri...

The effect of the addition of different metals (Cu, Rh, Pd, Ir, and Pt) into supported Ni catalysts on the catalytic performance of methane decomposition into pure hydrogen and carbon was examined. The addition of Pd brought about considerable increases in the catalytic life and in the accumulated yields of hydrogen and carbon at the complete deactivation of the catalyst, while modification with the other metals decreased the yields compared to those for Ni/SiO2. For the Ni catalysts modified with Pd, the appropriate preparation conditions of the catalysts, the effect of catalytic supports, and the optimum reaction temperature on the methane decomposition were examined. The hydrogen yield attained a high value, 16,000 molH2/molPd+Ni, when Pd and Ni were of a mole ratio Pd/(Pd+Ni)=0.5 and a total loading Pd+Ni=37 wt% on carbon nanofiber support. This yield is the highest among those reported so far. Methane decomposition over Ni catalysts modified with Pd produced carbon nanofibers with unique structures, i.e., branched carbon nanofibers. XRD studies on the Ni catalysts modified with Pd indicated the formation of Pd–Ni alloys. The alloys are responsible for the increase in the catalytic life and the formation of carbon nanofibers with unique structures.

According to a national survey of dialysis patients in Japan conducted by the Japanese Society for Dialysis Therapy, there were 1,033 patients on dialysis in the Shiga area which has a population of about 1.2 million. Of these 1,033 dialysis patients 140 were the result of diabetic nephropathy. From four hospitals affiliated to Shiga University of Medical Science the medical records of 90 diabetic subjects on dialysis therapy were reviewed and various clinical parameters were analysed and compared with those of patients with chronic glomerulonephritis. Since only one patient had Type 1 (insulin-dependent) diabetes, the remaining 89 with Type 2 (non-insulin-dependent) diabetes were used for this study. The significantly different variables between patients with Type 2 diabetes and chronic glomerulonephritis were age (60.4 vs 54.6 years,p

Alteration of mesangial response to ANP and angiotensin II by glucose. To test the hypothesis that the function of glomerular mesangial cells is impaired in diabetes, we examined the responsiveness of mesangial cells cultured under high concentrations of glucose to atrial natriuretic peptide (ANP 1 ) and angiotensin II (Ang II). The ANP-induced accumulation of cGMP was enhanced in mesangial cells cultured under high glucose conditions, possibly due to the activation of particulate guanylate cyclase. Ang II action in mesangial cells was evaluated by measuring the ability of Ang II to inhibit ANP-induced cGMP accumulation through both activating phosphodiesterase (initial phase) and inhibiting guanylate cyclase (maintenance phase). The inhibition of both ANP-induced cellular cGMP accumulation and particulate guanylate cyclase activity by Ang II was significantly reduced in mesangial cells cultured under high concentrations of glucose. Moreover, in the cells exposed to high concentrations of glucose, both basal and Ang II-stimulated levels of inositol 1,4,5-trisphosphate (IP 3 ) were significantly reduced. These results indicate that, in high glucose conditions, the actions of ANP and Ang II are modulated differently, resulting in the impairment of contractile responsiveness of mesangial cells.

In order to explore the possible contribution of insulin-like growth factor I to the development of diabetic nephropathy, the effect of glucose on the mitogenic and metabolic actions of insulin-like growth factor I in cultured rat glomerular mesangial cells was examined. The stimulation of [3H]-thymidine incorporation by insulin-like growth factor I in the cells exposed to high concentrations (55 mmol/l) of glucose (4.6 +/- 1.3 fold stimulation) was significantly suppressed as compared with that in the cells cultured in 11 mmol/l glucose (17.5 +/- 0.8 fold). In contrast, [3H]-amino-isobutylic acid uptake into the mesangial cells was significantly enhanced by glucose (2.03 +/- 0.03 nmol.mg protein-1. 15 min-1 at 55 mmol/l glucose vs 0.59 +/- 0.01 at 11 mmol/l glucose), while 2-deoxyglucose uptake remained unchanged. [125I]-insulin-like growth factor I binding was slightly but significantly increased in the cells exposed to high concentrations of glucose. Thus, glucose may modulate the mitogenic and metabolic actions of insulin-like growth factor I differently in cultured mesangial cells probably at the post-insulin-like growth factor I receptor level. These results may indicate that the differential modulation of the actions of insulin-like growth factor I by glucose could result in the increase in amino acid uptake and decrease in the cell proliferation in the mesangial cells, possibly leading to enhanced mesangial matrix synthesis with a relatively small increase in mesangial cell volume as seen in diabetic nephropathy.

To investigate the hepatic ketone body metabolism in NIDDM, we studied the ketone body production rates in hepatocytes from newly developed non-obese NIDDM model rats. NIDDM model rats were prepared by intraperitoneal injection of streptozotocin at 2 or 5 days of age (STZ2, STZ5 respectively). After 10-15 weeks, ketone body production rates in hepatocytes isolated from these rats were compared with those from control rats as well as ketotic rats made by intravenous injection of streptozotocin into adult rats. Basal ketone body production rates from 0.3 mM [U-14C] palmitate in hepatocytes from control, STZ 2, STZ 5 and ketotic rats were 11.7 +/- 0.98, 14.9 +/- 0.72, 16.0 +/- 0.45, 22.8 +/- 2.32 nmole.palmitate/mg.prot/hr, respectively. These rates were stimulated by 1 microgram/ml of glucagon in control, STZ 2 and STZ 5 rats (14.1 +/- 0.99, 18.6 +/- 1.36, 18.7 +/- 0.69 nmole.palmitate/mg.prot/hr, respectively), but not in ketotic rats (22.8 +/- 2.07 nmole.palmitate/mg.prot/hr). The similar effects were observed by 1 microgram/ml of epinephrine. The basal ketone body production rates were negatively correlated to both hepatic glycogen contents and plasma IRI levels. Considering these parameters together, the extent of metabolic derangement in STZ 2 and STZ 5 rats was between that in control and ketotic rats. These results indicate that the derangements of hepatic ketone body production are related to the severity of insulin deficiency and suggest that the enhanced hepatic ketogenesis contributes in part to the elevated plasma ketone body levels in non-obese NIDDM.

In order to clarify if vasopressin (VP) plays a role in the pathophysiology of hyperosmolar nonketotic diabetic coma (HNDC), VP has been infused to diabetic rats and plasma levels of glucose (PG), ketone bodies, FFA and glucagon were determined. High-dose VP infusion (1.2 U/kg/h) caused gradual elevation of PG (60%) and glucagon levels (600%), while ketone bodies showed transient decrease (20%) at 30 min. Under the suppression of endogenous glucagon secretion by constant infusion of somatostatin (100 micrograms/kg/h), high dose VP showed 25% increase in PG levels and 30% reduction of ketone body levels for the subsequent VP infusion for 1.5 hour. Low-dose VP infusion (0.06 U/kg/h) had no hyperglycemic effect, but suppressed ketosis (20%) in the same condition. There were no changes in plasma FFA concentrations, indicating no significant effect of VP on lipolysis. The results indicate that VP often elevated in HNDC may play an important role for the pathophysiology of HNDC through suppression of hepatic ketogenesis.

Dual mechanism of angiotensin II inhibits ANP-induced mesangial cGMP accumulation. To evaluate an interaction between vasoconstrictive (Ang II) 1 and vasodilating (Ang) peptides, we examined the effect of Ang II on ANP-induced accumulation of cGMP in cultured glomerular mesangial cells. ANP rapidly increased intracellular cGMP levels, with a peak stimulation at one minute in the absence of IBMX and at ten minutes in the presence of IBMX. The ANP-induced cGMP accumulation was significantly inhibited when the cells were treated with Ang II simultaneously with ANP for one minute in the absence of IBMX. This inhibitory effect of Ang II was completely abolished by IBMX and significantly reduced in calcium-free media or by W7, but not affected by H7. Similar inhibitory effect was observed when cells were treated with A23187 but not with TPA for one minute. In the presence of IBMX, Ang II inhibited ANP-induced cGMP accumulation when cells were treated with Ang II for 15 minutes prior to the stimulation by ANP. This inhibition by Ang II was blocked by H7. ANP-induced increase in particulate guanylate cyclase activity was significantly reduced in the cells treated with Ang II or TPA. This reduction of enzyme activity was also prevented by H7. These results indicate that Ang II inhibits ANP-induced cGMP accumulation in cultured glomerular mesangial cells through at least two mechanisms; one is the activation of calcium-dependent, calmodulin-stimulated cyclic nucleotide phosphodiesterase in the initial phase, and the other is the inhibition of guanylate cyclase resulting from protein kinase C activation in the maintenance phase.

We sought to evaluate the long-term efficacy and safety of epalrestat, an aldose reductase inhibitor, on diabetic peripheral neuropathy.Subjects with diabetic neuropathy, median motor nerve conduction velocity (MNCV)or=40 m/s, and HbA(1c)or=9% were enrolled in this open-label, multicenter study and randomized to 150 mg/day epalrestat or a control group. After excluding the withdrawals, 289 (epalrestat group) and 305 (control group) patients were included in the analyses. The primary end point was change from baseline in median MNCV at 3 years. Secondary end points included assessment of other somatic nerve function parameters (minimum F-wave latency [MFWL] of the median motor nerve and vibration perception threshold [VPT]), cardiovascular autonomic nerve function, and subjective symptoms.Over the 3-year period, epalrestat prevented the deterioration of median MNCV, MFWL, and VPT seen in the control group. The between-group difference in change from baseline in median MNCV was 1.6 m/s (P0.001). Although a benefit with epalrestat was observed in cardiovascular autonomic nerve function variables, this did not reach statistical significance compared with the control group. Numbness of limbs, sensory abnormality, and cramping improved significantly with epalrestat versus the control group. The effects of epalrestat on median MNCV were most evident in subjects with better glycemic control and with no or mild microangiopathies.Long-term treatment with epalrestat is well tolerated and can effectively delay the progression of diabetic neuropathy and ameliorate the associated symptoms of the disease, particularly in subjects with good glycemic control and limited microangiopathy.

Type IV collagen production by cultured glomerular mesangial cells and the effect of glucose on it were evaluated in order to explore the possible contribution of mesangial cells to the accumulation of type IV collagen in mesangial matrix typically seen in diabetes. Type IV collagen was measured quantitatively by enzyme-linked immuno-sorbent assay. The majority of type IV collagen was secreted into culture media and secreted-type IV collagen increased with cell growth in early log phase and decreased in late log phase and after confluency. By exposing the cells to high concentrations of glucose (27.8 mmol/l), both secreted- and cell-associated-type IV collagens increased significantly compared with the cells cultured under normal glucose concentrations (5.6 mmol/l) or under equivalent concentrations of mannitol, resulting in a significant increase in total type IV collagen accumulation from 32.1 +/- 6.4 (under 5.6 mmol/l glucose) to 51.0 +/- 4.6 micrograms/dish (mean +/- SD, n = 4) on day 4, from 113.6 +/- 6.6 to 156.8 +/- 7.1 on day 6, from 248.5 +/- 15.2 to 310.0 +/- 12.6 on day 8 and from 372.4 +/- 14.8 to 507.9 +/- 17.2 on day 12. These results indicate the importance of glucose-induced alteration of mesangial cell function in the development of diabetic mesangial expansion.

It has been reported that oxidative stress is increased in vivo in the diabetic state. Increased oxidative stress is caused not only by accelerated production of oxygen-free radicals but also by decreased scavenging of those molecules. Endothelial cells are extremely sensitive to oxidative stress, resulting in impairments of various endothelial cell function. In this report, we studied the association of intracellular glucose metabolism and oxygen radical scavenging function via the glutathione redox (GR) cycle in cells exposed to high-glucose conditions using cultured human umbilical vein endothelial cells. Glutathione-dependent H2O2 degradation in cells exposed to 33 mmol/1 glucose (HG) for 5–7 days was reduced by 48% vs. 5.5 mmol/1 glucose (NG). This impairment under the oxidative stress was D-glucose-specific and concentration-dependent and was also associated with a 42% decrease in intracellular NADPH content. Exposure of cells to 200 μmol/1 H2O2 stimulated the GR cycle and the pentose phosphate pathway (PPP) at the same time. In the HG condition, activation of PPP was reduced by 50%, which was consistent with a decrease in NADPH content. Inhibition of glycolysis by H2O2 was less marked in HG cells versus NG cells. Activation of polyol pathway in HG cells is not responsible for the decrease in intracellular NADPH content. These results indicate that activation of the PPP and NADPH supply to the GR cycle is impaired in HG cells exposed to H2O2, which may result in increased oxidative stress to endothelial cells.

In an attempt to evaluate the morphological abnormalities of dermal non-myelinated nerve fibers of diabetics and elucidate the pathogenesis of diabetic peripheral neuropathy, the terminal part of peripheral nerve in the upper dermis was observed on electron microscopy using skin samples biopsied in 10 diabetics with symptomatic neuropathy and 6 age-matched controls. In diabetics, the density of nerve fibers was significantly lower than in controls. In addition, swelling, lytic change and vacuolation in the axon, multiplication of basement membrane of the Schwann cell and Schwann cell cluster devoid of axon were more frequently observed in diabetics. The Schwann cell did not show significant structural alterations. These findings suggest that the axon is primarily involved, at least in the terminal region of nerve fiber, in diabetic peripheral neuropathy. It is also concluded that the skin biopsy technique is harmless, cosmetically not troublesome and might be beneficial for studying peripheral neuropathies including diabetic neuropathy.

Biological activity of six somatostatin analogs has been investigated. In these analogs, disulfide bond is replaced by ethylene bond cyclized with alpha-amino suberic acid. In addition, they contain unique D-configuration in both Trp8 and Cys14 moiety with dicarba substitution. An analog of the short chain length, C omega 7-cyclo (Phe6-Phe7-D-Trp8-Lys9-Thr10-Phe11-D-Asu14) (analog 4) has suppressive effect for GH, but not for other hormones. Analog 6, C omega 9-cyclo(Asn5-Phe6-Phe7-D-Trp8-Lys9-Thr10-Ph e11-Thr12-D-Asu14), has suppressed GH and insulin secretion, but not for gastrin and glucagon. Analog 1, C omega 11-cyclo (Lys4-Asn5-Phe6-Phe7-D-Trp8-Lys9-Thr10-Phe11- Thr12-Ser13-D-Asu14] and 5, C omega 9-cyclo (Lys4-Asn5-Phe6-Phe7-D-Trp8-Lys9-Thr10-Phe11-D-+ ++Asu14) have broad suppressive effect for GH, gastrin, insulin and glucagon release after arginine infusion. The shortest analog, analog 2, C omega 5-cyclo (Phe7-D-Trp8-Lys9-Thr10-D-Asu14) has weak suppressive effect of GH, insulin and glucagon secretion, and it is suggested that Phe6 and Phe11 are necessary for the appearance of suppressive effect of GH. Specific analog, analog 4, may be useful for the future treatment for acromegaly and diabetic retinopathy. Nonspecific analogs, 1 and 5 are candidates for the clinical application of wide variety.

An alteration of an amino acid sequence in the processing site of the insulin proreceptor by a point mutation of the insulin receptor gene produced extreme insulin resistance. We characterized functional properties of the unprocessed insulin receptor in transformed lymphocytes from a patient. Insulin binding to intact cells and to a partially purified insulin receptor preparation was radically decreased to 20% and 18% of the control values, respectively. In competitive insulin binding to intact cells, [LeuA3]-, [LeuB24]-, [SerB24]-insulin, and mini-proinsulin ([ B(1-29)-Ala-Ala-Lys-A(1-21)]-insulin) had the same relative binding activity in both the patient's and the control cells, but proinsulin and IGF-I were markedly less able to displace 125I-insulin in the patient's cells. In contrast to the study in intact cells, proinsulin and IGF-I as well as other insulin analogues had the same relative binding activity to bind to the partially lectin-purified insulin receptor preparations from both the patient's and the control cells. As regards the signal transduction after receptor binding, insulin-stimulated autophosphorylation of the unprocessed insulin proreceptor occurred proportionally to the amount of decreased insulin binding. With 0.025% trypsin treatment, the abnormal binding characteristics and autophosphorylation were normalized through conversion to functionally normal receptors. In spite of the abnormal processing, self-association of receptors into oligomeric structures was observed in the proreceptor. These results suggest that the unprocessed insulin proreceptor in the plasma membranes has an altered conformation which affects its binding characteristics but not its intramolecular signal transmission.

Water-in-oil-in-water (W/O/W) insulin emulsions with a concentration of 100 U/ml of insulin were prepared, and the possible absorption of insulin in emulsion form was examined. The following results were obtained: W/O/W insulin emulsions were quite resistant to proteolytic enzymes in vitro. In the presence of pancreatic lipase, however, W/O/W insulin emulsion gradually lost its activity by the action of proteolytic enzymes. When administered to the jejunum at doses over 10 U/kg, a significant and consistent increase in plasma insulin was observed, followed by a fall in blood glucose. The infusion of W/O/W insulin emulsions into the jejunum was three to four times more effective than the administration of aqueous insulin. Insulin, when administered to the stomach, did not cause hypoglycemia at doses up to 150 U/kg. When W/O/W insulin emulsions were administered orally, on the other hand, definite responses were observed in 3 out of 7 rabbits with 100 U/kg and in 4 out of 7 rabbits with 150 U/kg. For developing an effective method for oral administration of insulin, the present results indicate a possible means of protecting insulin molecule from proteolytic destruction, and of facilitating intestinal absorption of insulin.

The number of β-adrenergic receptors in cardiac myocytes isolated from rats made diabetic with streptozocin (STZ) for 10 wk was measured by use of a hydrophilic nonselective antagonist [3H]CGP 12177 and was found to decrease to 59% of the number in control rats (P < .05), without any change in affinity. Similarly, using [125I]iodocyanopindolol as a ligand, we found a decrease in the β-adrenergic-receptor number on cardiac plasma membrane isolated from the diabetic rats [29% decrease (P < .05) at 1 wk, 50% (P < .01) at 3 wk, and 49% (P < .01) at 10 wk compared with control rats]. However, the serum triiodothyronine level that had been known to modulate the β-adrenergic-receptor-adenylate cyclase system was decreased in the 1-wk-diabetic rats but not in the 10-wk-diabetic rats compared with each control group. Furthermore, there was no difference in urinary catecholamine excretion between diabetic and control groups. In the 10-wk-diabetic rats, the response of adenylate cyclase to isoproterenol was significantly defective (56% decrease compared with control rats; P < .05), although both the basal and the forskolin-stimulated maximum adenylate cyclase activities and a half-maximum concentration of isoproterenol for the stimulation of adenylate cyclase were similar in control and diabetic rats. On the other hand, both cholera toxin-dependent and islet-activating protein-dependent [32P]NAD incorporations into cardiac plasma membrane were markedly increased in the diabetic rats. The 2-wk insulin treatment improved not only the number of β-adrenergic receptors but also the response of adenylate cyclase to 10 μM isoproterenol. These results indicate that cardiac unresponsiveness to a β-adrenergic agonist in STZ-induced diabetic rats is specifically associated with a deficiency in the β-adrenergic-receptor concentration in cardiac plasma membrane.

We report a case of pancreatic pseudocyst which occurred in a 32-year-old woman with variant von Willebrand's disease. A curvilinearly calcified shadow incidentally seen in the upper abdomen on radiographic examination was the first sign of the cyst. The abnormality of hemostatic mechanism found in this patient is speculated to be related to the cyst formation.

The in vitro effect of glucocorticoid on insulin binding and glucose transport was studied with rat adipocytes. Isolated rat adipocytes were incubated with or without 0.70 microgram/ml (1.9 mumol) of hydrocortisone in TCM 199 medium at 37 degrees C, 5% CO2/95% air (v/v), pH 7.4, for 2, 4, and 8 h, and then fat cell insulin binding and insulin-stimulated 3-O-methylglucose transport were measured. Hydrocortisone did not affect insulin binding in terms of affinity or receptor number. Glucose transport in the absence of insulin was significantly decreased at the incubation time of 2 h and continued to decrease up to 8 h of incubation with hydrocortisone. Decreased insulin sensitivity of glucose transport (i.e., a right-ward shift of the dose response curve) was also demonstrated after 2 h incubation with hydrocortisone, and the ED50 of insulin was maximally increased at 4 h of incubation (0.53 ng/ml for treated vs. 0.22 ng/ml for control cells). Maximal insulin responsiveness was also significantly decreased in treated cells after 8 h incubation with hydrocortisone. When percent maximum glucose transport was expressed relative to receptor-bound insulin, the ED50 values of treated and control cells were 10.5 and 7.2 pg of bound insulin, per 2 X 10(5) cells, respectively. Thus, it was evident that glucocorticoid induced a post-receptor coupling defect in the signal transmission of insulin-receptor complex.

Focal hyperplasia of intracytoplasmic filaments of 100A in diameter was observed within chief cells of the parathyroid gland in dogs treated with nalidixic acid. The structure, as a rule, was located in the neighborhood of the nucleus and no other cell organelles were detected within it. Its size had a wide spectrum from a small part of the cytoplasm to as large as half a cell. Golgi apparatus and rough endoplasmic reticulum in the involved cells had a tendency to atrophy. These cells occasionally contained less secretory granules. Lipid droplets are diffusely increased. The pathogenesis and significance of the present intracytoplasmic filaments remain to be determined. However, as lipid deposition, atrophy of Golgi apparatus, poorly developed rough endoplasmic reticulum occur in a hypofunctional or degenerative state, it might be possible that filamentous hyperplasia is closely associated with that state.

Trypsin-catalyzed coupling of porcine desoctapeptide-insulin with synthetic octapeptides produced the [LeuB24]- (I), [LeuB25]- (II) and [LeuB24, LeuB25]- (III)analogues of human insulin. I, II and III displayed respectively 20--30%, 1--2% and 0.5% of the receptor binding activity of the normal hormone. Biological activities of these analogues seemed to be proportional to their binding potencies when assayed in vitro, while in an in vivo assay analogue I was fully active and II exhibited 10--20% of normal activity. III was less active than II in all assays tested.

Lipid peroxide content in hepatocytes isolated from ketotic diabetic rats was higher than normal, and the release of peroxide into the media was also elevated for the initial 18 h. Insulin suppressed both peroxide release and synthesis by cultured hepatocytes isolated from normal and from diabetic rats.

We examined antisera from patients treated with bovine-porcine mixture (hereafter referred to as bovine/porcine), porcine or human insulin, and compared their binding affinities to human insulin with those to porcine insulin. Patients treated with bovine/porcine insulin developed antisera with a higher affinity to porcine insulin compared with that to human insulin in five of nineteen cases. Furthermore, three of these five antisera had a comparable affinity to bovine and porcine insulin and appeared to recognize the amino acid residue at B-30. Treatment with porcine or human insulin, on the other hand, did not result in any significant difference in the affinity to porcine and human insulin in twenty-three patients. These results indicate the significant role of B-30 amino acid residue as an antigenic determinant, and suggest that the amino acid sequence of the A chain of bovine insulin may contribute to the development of antibody recognizing B-30 amino acid residue.

The direct action of angiotensin II on renal glomeruli was quantified by measuring extracellular space in isolated, decapsulated rat glomeruli using 14C-inulin. The glomerular inulin space significantly decreased when treated with 0.1 nM to 1 µM of angiotensin II. The decrease was dose-dependent and blocked by 1-Sar, 8-Ile angiotensin II. Since the glomerular intracapillary space seems to occupy the majority of the extracellular (inulin) space in decapsulated glomeruli, these results suggest that angiotensin II decreases the glomerular intracapillary volume. This action of angiotensin II may lead to a reduction in glomerular filtering surface area, and thus, in the ultrafiltration coefficient.