Diapedesis of thrombocytes from capillary into the intercellular space of interscapular brown adipose tissue and their increase by Ca-Sandoz.
Diapedetic capacity of the rat thrombocytes to leave capillaries of the interscapular brown adipose tissue (IBAT) and infiltrate the interstitium has been observed by conventional electron-microscopy. Thrombocytes that reach IBAT interstitium are morphologically completely different from lumenary ones. The interstitial thrombocyte has a prominet head region (1.51 x 2.12 microns) and very long phylopodium (3.43 microns). Experimental conditions which induced drastic changes in morphology of interstitial thrombocytes were: sucrose overfeeding (10% over 2 days); a 24 hour starving after sucrose overfeeding and Ca-Sandoz drinking (480 mg/L Ca2+ during 2 days). The thrombocytes in the IBAT interstitium can be classified as activated according to: a) pseudopode extension; b) swollen open canalicullar system (OCS); c) endocytosis via coated pits and vesicles; and d) structural changes in alpha granules excreted to the interstitium through OCS. In the IBAT interstitium of 24-hour starved rats after sucrose overfeeding, a thrombocytic layer was observed. It was suggested that thrombocyte adrenalin, stored in dense bodies, was selectively included in the IBAT supply without mediation of the central nervous system.
Institute of Zoology, Faculty of Biology, University of Belgrade, Yugoslavia. jelenar@bf.bio.bg.ac.yu
J
J
Radovanović
A
A
Korać
V
V
Koko
M
M
Nedeljković
N
N
Drndarević
D002001:Adipose Tissue, Brown / Q000166:cytology*; D000818:Animals; D001792:Blood Platelets / Q000166:cytology*; D002118:Calcium; D002196:Capillaries / Q000166:cytology*; D002465:Cell Movement; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D007424:Intracellular Fluid; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013395:Sucrose / Q000378:metabolism
D013395:Sucrose; D002118:Calcium