Biomedical subjects

K Shima

Publications and source records attributed to K Shima.

At least 415 records · Page 23Linked to original sources

PubMed1983

Effect of synthetic chicken vasoactive intestinal peptide on pancreatic blood flow and on exocrine and endocrine secretions of the pancreas in dogs.

This study was undertaken to determine the effect of synthetic chicken vasoactive intestinal peptide (VIP) on pancreatic blood flow, exocrine and endocrine secretions of the pancreas, and biliary secretion in dogs. The effect of synthetic chicken VIP on pancreatic blood flow and systemic arterial pressure was identical to that of natural chicken VIP in dogs. The present study demonstrated that synthetic chicken VIP induces significant increases in pancreatic blood flow, pancreaticobiliary secretion, and blood levels of insulin and glucose in dogs. Both the volume of pancreatic juice and blood levels of insulin were increased in consonance with the increase of pancreatic blood flow. This study suggests that the stimulatory effects of synthetic chicken VIP on exocrine and endocrine secretions of the pancreas may be related to the increased pancreatic blood flow elicited by synthetic chicken VIP.

Animals↗

PubMed1983

Follicle-stimulating hormone and luteinizing hormone receptors on porcine granulosa cells during follicular maturation: an autoradiographic study.

The autoradiogram prepared from porcine ovaries after incubating for 1 hour at 37 degrees C with either 125I-labelled FSH or LH revealed that FSH bound to granulosa cells while LH bound to thecal cells. Although the granulosa cells of small, medium and large follicles were labelled with FSH, the decrease in grains over granulosa cells was observed during follicular maturation. In contrast, the granulosa cells of small and medium follicles showed only slight labelling with LH, while the granulosa cells of large follicles showed heavy labelling. The present study also indicated that granulosa cells collected from small follicles bound much more 125I-labelled FSH per cell than did cells from medium or large follicles, and granulosa cells harvested from large follicles bound much more 125I-labelled LH per cell than did cells from small or medium follicles. The competition studies with unlabelled hormones revealed that porcine granulosa cells had specific receptors for FSH and LH. The results of the present study suggest that a marked change in the binding of FSH and LH to the granulosa cells from the three follicle types might play a role in follicular growth and maturation.

Animals↗

PubMed1983

Effect of dietary fiber, glucomannan, on absorption of sulfonylurea in man.

In order to clarify whether a dietary fiber has any effect upon the intestinal absorption of sulfonylurea, changes in plasma concentration of glibenclamide were determined during a six-hour period in nine healthy volunteers who took 2.5 mg of glibenclamide together with a breakfast and 3.9 g of glucomannan in a form of konjac powder and were compared with those of the control experiment in which the same amount of the hypoglycemic agent was given without the dietary fiber. In the control, mean plasma glibenclamide level increased rapidly, reaching a peak at 60 min and decreased gradually thereafter, whereas an increase in plasma glibenclamide level was blunted in the test experiment, thus plasma concentration of glibenclamide being lower at 30, 60, 90 and 150 min compared with the corresponding value of the control (31.7 +/- 24.5 ng/ml vs 76.4 +/- 25.0 ng/ml at 30 min; 51.3 +/- 35.5 ng/ml vs 120.9 +/- 56.0 ng/ml at 60 min; 60.0 +/- 38.8 ng/ml vs 117.4 +/- 53.1 ng/ml at 90 min; 54.0 +/- 31.5 ng/ml vs 100.7 +/- 46.5 ng/ml at 150 min). Mean plasma glucose concentration was significantly lower at 30 min in the test experiment than in the control despite the lower level of plasma glibenclamide in the former. The results suggest that glucomannan may influence the intestinal absorption of glibenclamide. A dietary fiber must be prescribed in due consideration of these facts.

Adult↗

PubMed1983

Glucagon secretory responses to insulin-induced hypoglycemia and arginine in streptozotocin-induced diabetic dogs.

To clarify whether the reactivity of A cells is regulated by B cell function in the pancreas, plasma glucagon (IRG) responses to insulin-induced hypoglycemia and to arginine infusion were evaluated in streptozotocin (STZ; total 40 mg/kg) treated and control dogs. There was no significant rise in plasma IRG levels during the insulin-induced hypoglycemia in the STZ-treated dogs. In contrast, arginine enhanced the IRG secretion from the pancreas to a similar extent in the two groups. This was deduced from the difference between IRG levels in the pancreaticoduodenal and peripheral veins. Neither intravenous glucose nor arginine infusion resulted in a significant rise in plasma insulin (IRI) levels in the STZ-treated dogs. IRI content in the pancreas of STZ-treated dogs was significantly reduced to 5 percent below the levels in the control dogs. The IRG content for control and STZ-treated dogs did not differ. These results indicate that while the responsiveness of A cells to hypoglycemia may depend on the secretory capacity of B cells, such is not the case with arginine.

Animals↗

PubMed1983

Plasma inactive renin in diabetic patients with neuropathy: a role for the sympathetic nervous system in the conversion in vivo of inactive renin.

Plasma levels of active and trypsin-activatable inactive renin and catecholamines were measured in 6 diabetic patients with neuropathy (group 1), 8 diabetic patients without neuropathy (group 2) and 8 age-matched normal subjects. The effect of insulin administration on plasma active and inactive renin and plasma catecholamine levels in diabetic patients was also investigated. The levels of inactive renin were calculated as the difference between the levels of total renin after trypsin activation and those of active renin. The levels of plasma catecholamines were determined by the trihydroxyindole method. The levels of active renin were significantly lower and inactive renin was increased slightly in group 1 when compared with controls. Group 1 showed a significant reduction in plasma norepinephrine levels. Group 2 showed slightly reduced active renin, normal inactive renin and normal norepinephrine values. There was no significant difference in the levels of epinephrine between the 3 groups. After insulin injection, active renin levels were increased in groups 1 and 2. The mean increment in active renin levels was less in group 1 than in group 2. Inactive renin levels were slightly decreased in both groups. Significant increases in epinephrine and norepinephrine levels were observed following insulin administration. The mean increment in norepinephrine levels was less in group 1 than in group 2. There was a positive correlation between the mean increment in active renin and in norepinephrine levels in diabetic patients. These results suggest that the impaired conversion of inactive renin into an active form is responsible in part for the low levels of active renin in diabetics with neuropathy.

Diabetes Mellitus↗

PubMed1983

Quantitative analysis of the sympathetic efferent activity to characterize the integrative function of the sympathetic ganglion.

Using the concept of the Markov dependency, we analyzed the spontaneous activity in the pre- and postganglionic nerve trunks of the feline superior cervical ganglion. The time structure (order and value of time dependency) of the sequence of compound action potentials was determined. The analysis revealed that the time dependency of the postganglionic activity is of higher order and is generally more consistent than that of the preganglionic one. The difference in orders and values between the pre- and postganglionic activities was found to be a measure of the integrative function of the ganglion. A transformation by the ganglion of some additional information, inaccessible in the time structure of the preganglionic activity, seems to underlie this difference.

Action Potentials↗

PubMed1983