List of abbreviations
Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!
|RER secreting vesicles
(only on right at bottom)
rat seminal gland
|RER in a cell of the
exocrine pancreas (monkey)
|RER in a plasma
|dilated RER in a Bowmann's
nasal gland cell (monkey)
|RER in liver cells
|dilated RER of
a plasma cell (rat)
|Detail: dilated RER and
|RER & Golgi-Apparatus
of a plasma cell (rat)
|dilated RER of a
|RER of a human
|lots of RER in a chief cell
of the stomach (pig)
|RER in Nissl bodies,
ganglion cell (guinea pig)
|detail: Nissl body
= RER + ribosomes
|RER + Nissl bodies, Pur-
kinje cell cerebellum (rat)
|formation of a Nissl
body cerebellum (rat)
|isolated RER tubes
neuron cerebral cortex (rat)
|RER in an endocrine cell
| human plasma cell RER, pharyngeal
tonsil (Tonsilla pharyngea)
|human plasma cell RER 2
parotid gland (rat)
|human plasma cell
|plasma cell: RER
|RER + lipofuszin-
vesicle, human plasma cell
|RER of a human
|RER + primary lysosomes
of a human plasma cell
|partly dilated RER,
parotid gland (rat)
The rough- or granular endoplasmic reticulum
(Terminologia histologica: Reticulum endoplasmicum granulosum) is a complex
network of lamellas (Terminologia histologica:
saccules (Terminologia histologica: Sacculi),
tubules and flat
are bound to its outer surfaces in more or less regular pattern. The lumen
(Terminologia histologica: Lumen) is bordered by membranes (Terminologia
histologica: Membranae) and is extremely rich in proteins (concentration:
200 g per litre). All RER membranes have an outer surface (cytosolic surface;
Terminologia histologica: Facies externa) directed towards the cytoplasm
and an inner surface (luminal surface; Terminologia histologica: Facies
interna) bordering the lumen. The paired membranes of the RER have
a distance of 20-60 nm. Local dilatation of the RER is seen
when high protein synthesis and storage is necessary. The RER membranes
may be outfoldings of the outer nuclear membrane,
resulting in a continuity of perinuclear space (space between
and inner nuclear membrane)
and RER lumen.
RER collects, modifies, stores and transports proteins that are synthesised by the ribosomes anchored to the outer membrane of the RER. Many of these proteins are not for the cell itself but for secretion. In cells of glands, but also in most polar cells the RER is located more basally, followed by a Golgi-zone while above the latter the secretion vesicles accumulate in the apical cytoplasm.
RER forms small vesicles that are transported either to the Golgi-apparatus or to the cell membrane. The proteinaceous content of these vesicles is released after membrane fusion.
The greater the protein synthesis of a cell, the higher its content in RER. High amounts are usually seen in plasma cells, exocrine pancreas cells, neurons, osteo-, chondro- and fibroblasts.
A continuity of rough into smooth ER is possible and may be seen e.g., in cells of the liver. In neurons, RER occurs in parallel membrane plates and is associated with free ribosomes as Nissl-body (chromatophilic substance or Tigroid-substance; Terminologia histologica: Substantia chromatophilica).
In light microscopic stains RER is basophilic since its ribosomes bind messenger ribonucleic acids; RNAs. The latter carry the genetic information for the amino acid sequences of proteins synthetised in the RER in the process of translation.
Further detailed information is available in the professional version of this atlas.
--> smooth ER, ribosomes,
membrane, secretory vesicles, plasma
--> Electron microscopic atlas Overview
--> Homepage of the workshop
Three pictures were kindly provided by Prof. H. Wartenberg; further images, page & copyright H. Jastrow.