ISSN:
1432-0878
Keywords:
Crustacean hyperglycemic hormone
;
Astacus leptodactylus
;
Immunocytochemistry
;
Day/night rhythmicity
;
Neurosecretion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The secretory dynamics of the Crustacean Hyperglycemic Hormone (CHH)-producing cells in the eyestalk of the crayfish Astacus leptodactylus were studied during the daily cycle (12 h light/12 h dark). The different secretory stages of individual cells were determined by means of immunocytochemistry combined with morphometric analysis at the light-microscopic level. The data obtained were correlated with the 24-h rhythmicity of blood glucose concentration. The results suggest the following hypothesis. The synthetic activity of the CHH cells receives a stimulus 2 h before the beginning of the dark period, resulting in a pronounced transfer of CHH granules into the axons. These CHH granules reach the axon terminals after the onset of the dark period. At that time a burst of exocytotic activity occurs, causing a strong release of CHH into the hemolymph. Four hours later this CHH release results in hyperglycemia. The same process, though with less intensity, is repeated and causes a second smaller glucose peak at the beginning of the light period.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00217181
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