List of abbreviations
of micros-
specialist terms
explained in
English +

Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!

dieser Seite

Dr. med.
H. Jastrow

of use
Overview aggregated macrotubules (Macrotubuli aggregati; MA):
All images were taken from horizontal cells of human retina.
horizontal cell with
macrotubuli aggregati
MA 1
MA 2
MA 3
Detail 1 showing MA MA Detail 2
longitudinally sectioned MA
longitudinally sectioned
MA Detail 3
longitudinally sectioned
MA Detail 4
MA in a preparation fixed
14 hours post mortem
MA with multiple
layered walls overview
MA with triple
layered wall
Macrotubuli aggregati (MA; English: aggregated macrotubules) are known as Kolmer`s crystalloids, a not quite correct term derived from light microscopy. They are grouped large tubes running almost parallel to each other. Their walls consist of obliquely running parallel intermediate filaments (diameter: 12.5 nm). They have simple, single layered walls in over 97%. However, few of them show double or multiple layered walls. Large amounts of ribosomes are attached mainly to the inner walls of the tubes via fine stalks. The mean diameter of the tubes is 235.7 ± 29.7 nm. Their length may reach over 10 µm. MA are present in about 20% of all horizontal cells in human retina. They could not be detected in other species investigated so far with few exceptions: rhesus monkey, chimpanzee, beagle dogs. Further MA were noted in pathological human cornea and in the pinealocytes of one mouse species (Acomys cahirinus dimidiatus). Probably they support the cytoskeleton and serve as storage site for ribosomes, however their function still remains to be elucidated.

--> Presentation on Macrotubuli aggregati providing further information
--> human retina  - retina of other mammals
--> Electron microscopic atlas: Overview
--> Homepage of the workshop

I am grateful to Prof. B. Stoffelns (University eye clinic Mainz), Prof. N. Ardjomand, Prof. E. Haller-Schober and M. Theisl (University clinic Graz) for the provided specimens. Images, page & copyright H. Jastrow.