ISSN:
1432-0878
Keywords:
Islands of Langerhans
;
Endocrine glands
;
Nerve endings
;
Alloxan
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The innervation of the islets of Langerhans of normal albino rats and of albino rats treated with several daily doses of 125 mg/kg of alloxan was studied by electron microscopy. In the normal rat, nerve endings containing either agranular vesicles (200–400 Å) alone or in combination with large granular vesicles (500–800 Å) were found on both alpha and beta cells. Infrequently a third type of nerve ending containing small granular synaptic vesicles could be observed. Bundles of unmyelinated axons were also seen, as were typical autonomic ganglion cells. Similar normal neural elements were noted in rats treated with alloxan. However, islets of alloxan-treated animals also possess large elliptical profiles which appear to be dystrophic nerve terminals. These structures most frequently contact degranulated beta cells. Islets of Langerhans fixed with zinc iodide-osmium (ZIO) reported to specifically impregnate synaptic vesicles were also studied. Synaptic vesicles of normal axons and nerve endings as well as of the dystrophic structures were filled with ZIO reactive material. These studies suggest that alloxan may induce autonomic nerve ending changes in the rat endocrine pancreas. This may result from neuronal hyperactivity in an attempt to secrete insulin from the post-alloxan insulin-depleted beta cell.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00335397
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