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Biomedical subjects

A Noda

Publications and source records attributed to A Noda.

At least 199 records · Page 11Linked to original sources

Plasma pancreatic glucagon response to blood glucose in experimental pancreatolithiasis in dogs.

In an attempt to study pancreatic A cell function at an early stage of pancreatic diabetes secondary to chronic pancreatitis, both intravenous glucose (0.5 g/kg) and insulin (0.5 U/kg) tolerance tests were performed on seven dogs with pancreatolithiasis and seven normal control dogs. Experimental pancreatolithiasis was produced 12 months after incomplete ligation of the greater pancreatic duct. Impaired glucose tolerance and reduced plasma insulin response to an intravenous glucose load were observed in the calcified group. Pancreatic release of glucagon to insulin-induced hypoglycaemia was diminished, but suppressive response of the hormone to glucose-induced hyperglycaemia was well preserved. These data suggest that the A cell response to hypoglycaemia may be impaired earlier than that to hyperglycaemia in pancreatic diabetes secondary to pancreatolithiasis.

Animals↗

Clinical evaluation of pancreatic excretion test with dimethadione and oral BT-PABA test in chronic pancreatitis.

Further evaluation of the pancreatic excretion test with 5,5-dimethyl-2,4-oxazolidinedione (dimethadione, DMO) was made in comparison with the pancreozymin-secretin (PS) test on 100 normal subjects, 79 patients with chronic pancreatitis, and 83 patients with nonpancreatic disease. The diagnostic sensitivity of the oral N-benzoyl-L-tyrosyl-PABA (BT-PABA) test was estimated in 42 patients with chronic pancreatitis, on whom both PS and DMO excretion tests were performed as test of reference for exocrine pancreatic function. Pancreatic DMO excretion after secretin injection was significantly diminished in chronic pancreatitis. The DMO excretion test was more sensitive than the PS test to detect chronic pancreatitis and to distinguish between mild to moderate and advanced noncalcific chronic pancreatitis. The specificity of the DMO excretion test was more than adequate to find out pancreatic disease. The 6-hr urinary PABA excretion was significantly reduced in chronic pancreatitis. The BT-PABA test, however, showed the low sensitivity in mild to moderate chronic pancreatitis.

4-Aminobenzoic Acid↗

Effect of environmental temperature on the content of cytochrome P-450 and activity of NADPH-cytochrome C reductase in rats.

The effect of environmental temperature on the content of cytochrome P-450 or the activity of nicotinamide adenine dinucleotide phosphate-cytochrome c (NADPH-cytochrome c) reductase was examined by using microsomes prepared from rats kept at 30 degrees C or 15 degrees C for 14 d. The warm exposure (30 degrees C for 14 d) resulted in a significant reduction of the activity of NADPH-cytochrome c reductase though the content of cytochrome P-450 was not changed. The level of thyroxine and 3,3',5-triiodothyronine was reduced by the warm exposure. From the present observation, it was suggested that the effect of environmental temperature on the metabolism of drugs was due to the activity of NADPH-cytochrome c reductase mediated by the level of thyroid hormone.

Animals↗

Brain distribution of hydrazine and its GABA elevating effect in rats.

After the intravenous administration of isoniazid (INH; 0.37 mmol/kg) or hydrazine (Hz; 0.16 mmol/kg), the minor metabolite of INH, gamma-aminobutyric acid (GABA) and Hz were measured by means of gas chromatograph-mass spectrometer (GC-MS) using deuterium labeled GABA (d2-GABA) and nitrogen fifteen labeled Hz (15N-Hz) as internal standards. In both cases, we successfully detected Hz and GABA in the brain. The brain GABA elevating effect of Hz was much higher than that of INH in spite of low dose.

4-Aminobutyrate Transaminase↗

Influence of phenobarbital and 3-methylcholanthrene on the metabolism of aminopyrine in isolated hepatocyte system.

The effect of phenobarbital (PB) and 3-methylcholanthrene (3-MC) on the metabolic behavior of aminopyrine (AM) was studied using an isolated hepatocyte system prepared from male Wistar rats. The formation of 4-formylaminoantipyrine (FAA) was increased after pretreatment with PB, but not 3-MC. However, the total amounts of AM and its main metabolites recovered from hepatocyte system after the incubation for 30 min were considerably reduced both by PB and 3-MC-pretreatment. Furthermore, when using 4-monomethylaminoantipyrine (MAA), the first metabolite of AM, as a substrate, 3-MC-pretreatment resulted in a more significant decrease in the total amounts of MAA and its further metabolites recovered than did PB. Present observation suggests the participation of cytochrome P-448 as well as cytochrome P-450 in the metabolism of AM.

Aminopyrine↗

Further investigations on brain distribution of hydrazine and its gamma-aminobutyric acid elevating effect in rats.

Perry's hypothesis that hydrazine (Hz) derived from isoniazid (INH) treatment plays an important role in the elevation of brain gamma-aminobutyric acid (GABA) levels was reexamined by measuring Hz and GABA levels in the brain after the treatment with 50 mg/kg of INH or different doses of Hz. The treatment with 50 mg/kg of INH to rats resulted in the elevation of GABA levels in rat whole brain. The maximum levels of GABA increased about twice at 4 h from 2.06 +/- 0.4 mumol/g wet wt. in the control group to 3.61 +/- 0.4 mumol/g wet wt. in INH treated group. In this case, brain levels of Hz ranged from 25.6 to 80.8 ng/g wet wt. within 10 h. On the other hand, Hz levels after the treatment with 0.5 mg/kg of Hz were about five times higher than those after INH treatment. However, 0.5 mg/kg of Hz treatment did not increase brain GABA levels at all. Perry's hypothesis was denied by the fact that brain Hz levels after INH treatment were too low to elevate brain GABA levels.

Animals↗

Postprandial pancreatic secretion and plasma hormones in dogs with pancreatic fistula.

The responses of exocrine pancreas, plasma secretin, and gastrin to a test meal were studied in six dogs prepared with gastric and duodenal fistulas. The experiment was doubly repeated in each dog. Pancreatic juice was diverted to the exterior by direct cannulation into the major pancreatic duct. Volume, bicarbonate, and protein secretion of pancreatic juice were rapidly increased and then gradually reduced after the ingestion of the meal. Plasma secretin concentration reached a peak at 25 min after the ingestion of the meal and remained higher than the basal level for about 3 h. Plasma gastrin concentration rapidly reached a higher plateau which lasted for 40 min after the load of the test meal. A close correlation was observed between bicarbonate secretion and the increment in plasma secretin concentration and between protein secretion and the increment in plasma gastrin concentration. When pancreatic juice is diverted to the exterior, endogenously released secretin and gastrin appear to play an important role in postprandial pancreatic secretion.

Animals↗

Lactoferrin in pure pancreatic juice in chronic pancreatitis.

To investigate the role of lactoferrin in intraductal protein precipitates in chronic pancreatitis, lactoferrin was measured in pure pancreatic juice collected by endoscopic retrograde pancreatic cannulation using a sensitive and specific radioimmunoassay. Significant gradual increase in the lactoferrin concentration and output was observed in chronic pancreatitis (mean +/- SE = 1.13 +/- 0.04 microgram/ml, 1.61 +/- 0.44 microgram/min for five controls; 4.73 +/- 0.70 microgram/ml, 14.1 +/- 2.86 micrograms/min for 15 patients with noncalcified mild chronic pancreatitis; 23.6 +/- 4.7 micrograms/ml, 28.4 +/- 13.4 micrograms/min for four with chronic pancreatitis with visible protein plugs or calculi). The total protein in the juice gradually decreased in chronic pancreatitis (12.8 +/- 1.48 mg/ml for control, 7.6 +/- 1.37 for noncalcified, 5.2 +/- 1.27 for patients with plugs or calculi). Lactoferrin appears to rise as the disease progresses and although this may be important etiologically, it may also just be an accompanying protein which increases as the disease progresses.

Adult↗

Studies of isoniazid metabolism in isolated rat hepatocytes by mass fragmentography.

Isoniazid metabolism in isolated rat hepatocytes was studied by mass fragmentography using single ion monitoring. Isoniazid and its metabolites were determined as the trimethylsilylated derivatives of acetylisoniazid and diacetylhydrazine and of the benzaldehyde hydrazones of isoniazid and acetylhydrazine. Deuterated analogues served as internal standards. Hydrazine was quantitated as benzalazine using 15N-labeled hydrazine as an internal standard. The method is well suited for the microanalysis of isoniazid metabolism, from which it was clarified that the greater part of hydrazine, a hazardous metabolite of isoniazid, was formed through the direct hydrolysis of isoniazid itself as expected.

Acetylation↗

Plasma pancreatic glucagon in pancreatic and primary diabetes, and liver cirrhosis: application of a correction to the radioimmunoassay for pancreatic glucagon.

Evidence is present that plasma contains non-specific factors which interfere with the 30K glucagon assays. A correction can be made for these interference factors because the factors can be quantitated following absorption of glucagon with charcoal-dextran. Using a correction factor the range of fasting plasma immunoreactive glucagon (IRG) in 12 totally pancreatectomized patients was below detectable limit. Fasting levels of IRG were determined on the plasma from 25 liver cirrhotics complicated by abnormal GTT, 13 pancreatic diabetics with chronic calcified pancreatitis (CCP), 25 adult-onset primary diabetics and 25 healthy subjects. When all samples were measured using no correction factor, the mean levels of IRG were 358 +/- 24 (mean +/- SE), 170 +/- 26, 178 +/- 16 and 178 +/- 7 pg/ml, respectively. Using a correction factor the mean level of IRG were 177 +/- 26, 16 +/- 4, 39 +/- 9 and 20 +/- 4 pg/ml, respectively. The mean values of the interference factor were not significantly different among all five groups. During an arginine infusion the interference factor remained unchanged despite an increase in IRG. It is available but not always necessary to apply a correction factor for 30K glucagon radioimmunoassay.

Aged↗

Influence of topical anesthetic, anticholinergic and ganglionic blocking agents on endogenous secretin release and pancreatic secretion in dogs.

The role of parasympathetic including local nerve control on the release of endogenous secretin and pancreatic secretion was studied in four conscious dogs prepared with both Thomas duodenal and gastric fistulae. Plasma secretin levels and pancreatic response during intraduodenal infusion of hydrochloric acid (HCl, graded doses doubling every 30 minutes from 0.3 to 2.4 mEq/10 min) rose significantly in dose-related fashion. Either atropine or hexamethonium, when given intramuscularly, did not inhibit HCl-stimulated endogenous release of secretin, but significantly suppressed pancreatic water, bicarbonate and protein secretions. Oxethazaine, when infused with HCl, suppressed a rise in both plasma secretin concentration and pancreatic secretion. The results obtained led to the conclusion that endogenous release of secretin is not under parasympathetic nervous control, but stimulated directly by intestinal contents.

Anesthetics, Local↗

The role of gastric secretion in post-diverted pancreatic hypersecretion in conscious rats.

1. In rats prepared with chronic external pancreatic fistulae, gastric fistulae and choledocho-enterostomy, the volume and protein secretion of pancreatic juice was measured. 2. The pancreatic secretion of water and protein after juice diversion was significantly lower when the gastric fistula was open than when closed. Secretion was abolished after atropine, with the fistula open and in animals with ligated pylori. 3. Intraduodenal HCl significantly raised juice volume and protein in animals with diverted juice when the gastric fistula was open. 4. Soybean trypsin inhibitor produced a significantly smaller elevation of juice volume and protein when the gastric fistula was open. 5. It is concluded that the initial hypersecretion of pancreatic juice and protein, following its diversion from the duodenum, is a consequence of the entry of gastric juice into the intestine.

Animals↗

Changes in serum pancreatic enzymes during 2 months' abstinence in asymptomatic chronic alcoholics.

To elucidate the injurious effects of alcohol on the human pancreas, serum pancreatic enzymes were followed for the first 2 months of abstinence in 31 asymptomatic alcoholics. Sequential declines of serum enzymes were observed in immunoreactive human pancreatic elastase 1 and trypsin (IRE and IRT) as well as gamma-glutamyl transpeptidase (gamma-GTP), creatine phosphokinase (CPK) and glutamate-oxaloacetate transaminase (GOT) during the abstinence. The incidence of abnormally high enzyme activities found initially changed by the end of 2 months of abstinence as follows: from 55 to 6% for IRE, from 25 to 0% for IRT, from 3 to 6% for amylase, from 76 to 22% for gamma-GTP, from 69 to 39% for CPK, from 55 to 12% for GOT, and from 38 to 12% for GPT, respectively. The decline suggests that excessive intake of alcohol enhances the escape of the enzymes from the pancreas into the serum, probably altering membrane permeability or cellular metabolism of the pancreas, a direct toxic effect of alcohol.

Adult↗