Decreased adrenal medullary catecholamine release in spontaneously diabetic BB-Wistar rats. Role of hypoglycemia
Decreased adrenal medullary catecholamine release in spontaneously diabetic BB-Wistar rats. Role of hypoglycemia. R A Wilke and C J Hillard Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226. Abstract We have demonstrated previously that spontaneously diabetic B...
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Published in | Diabetes (New York, N.Y.) Vol. 43; no. 5; pp. 724 - 729 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
American Diabetes Association
01.05.1994
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Online Access | Get full text |
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Summary: | Decreased adrenal medullary catecholamine release in spontaneously diabetic BB-Wistar rats. Role of hypoglycemia.
R A Wilke and
C J Hillard
Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226.
Abstract
We have demonstrated previously that spontaneously diabetic BB-Wistar rats exhibit decreased adrenal medullary catecholamine
secretion in response to splanchnic nerve terminal stimulation. We hypothesized that this abnormality is caused by changes
in the sensitivity of the adrenomedullary chromaffin cells to acetylcholine (ACh). To study this hypothesis, we isolated adrenal
glands from control and spontaneously diabetic BB-Wistar rats, perfused them with ACh, and measured catecholamine secretion.
Adrenal catecholamine release in response to ACh was significantly decreased at 2, 8, and 16 weeks after the onset of diabetes
compared with age-matched, nondiabetic control rats. Catecholamine release in response to perfusion with 20 mM K+ was the
same in adrenals from diabetic and control rats. The decreased responsiveness of diabetic rat adrenals to perfusion with ACh
was significantly correlated with a decrease in the release of catecholamines in response to splanchnic nerve stimulation.
A similar defect in catecholamine secretion was also seen in adrenals harvested from nondiabetic BB-Wistar rats following
a 3-h period of acute hypoglycemia; however, the adrenal response to potassium was also decreased as was the catecholamine
content of the adrenal. Conversely, nondiabetic BB-Wistar rats made diabetic with streptozocin (STZ) and maintained in a hyperglycemic
state did not exhibit catecholamine hyposecretion 2 weeks after STZ administration. Collectively, the data describe decreased
adrenomedullary response to cholinergic stimulation in spontaneously diabetic rats as early as 2 weeks after the onset of
diabetes and that a similar, although more severe, hyposecretion occurs after acute, severe hypoglycemia. |
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ISSN: | 0012-1797 1939-327X 0012-1797 |
DOI: | 10.2337/diabetes.43.5.724 |