Category Archives: Electron micrographs of liver

Intra-cristae – membrane protein organized in mitochondria

Electron micrographs of liver, Environment and contaminants, Mitochondria: electron microscopy, Ultimate order, the cell

Intracristae – membrane protein organized in mitochondria — found in guinea pig liver electron micrographs in a retrospective study on vinyl chloride (and air) and vitamin C exposure from the 1980s. These cristae with apparent organizations of ATP synthase in a long row, parallel and sometimes looking staggered, sometimes aligned, have appeared in exposed as well as control (both groups receiving vitamin C). This is an awesome image with a 3-layered row of highly organized molecules looking a little like they are strung together somehow, yet each distinct. Just marvel at the order in the completely UNRETOUCHED electron micrograph  of a mitochondrion in guinea pig liver here.

4158_M8011_guinea_pig_liver_VC_vitC_HRMitochondria in both control and experimental data sets have mitochondria with wild shapes, very atypical for mitochondria in general, in some cases on section looking like asterisks (yep, same type outer membrane configuration seen in apoptotic cells). This is the case of the mitochondrion shown enlarged (the scalloped edges are just cropped so the ATP synthase is more visible. Image below 5924_17010_guinea_pig_air_vitC_liver.

As with the intracisternal body in the alveolar type II cell of the lung of many guinea pigs, when the protein within the cisternae of the RER begins to assume a substructure (in that case, a layered granule), then the resulting RER becomes very rigid looking.  Similarly here, when the cristae have the ATP synthase all aligned in alternating double rows, the intramitochondrial membrane and other elements in the mitochondria also take on a rigid appearance.

5924_17010_guinea_pig_air_vitC_liverMicrograph below shows a section of an example of odd shaped mitochondrion with an area of extended ATP synthase molecules head to head, and on the inner mitochondrial membrane a little bit of rigidity and a thickening of the membrane is seen (arrow).

3548_M7991_guinea_pig_air_vitC_liverHere is a mitochondrion with an extended section of rigidity in the mitochondria membrane adjacent to a TRIPLE row of ATP synthase molecules, lucky cut (I hope that is what this is), and again rigidity in the mitochondrial membranes in this zone, and inner mitochondrial membrane has a slightly increased electron density about it (which of course means something, but I don’t know what).

4158_M8011_guinea_pig_liver_VC_vitC
HERE is a nice article…. it says the protein is in the matrix, which is not what is seen in the micrographs above, it is in cristae…. so there is some explaining to do on this topic.

Vinyl chloride and low Vit C exposure: guinea pig, liver, mitochondrion, intramembrane proteins

Electron micrographs of liver, Environment and contaminants, Mitochondria: electron microscopy, The cell: images, Ultimate order, the cell

Vinyl chloride and low Vit C exposure: guinea pig, liver, mitochondrion, intramembrane, inclusions — a long title. This is an electron micrograph from the liver of guinea pig # 7 in a study about inhalation of vinyl chloride in conjunction with / without vitamin C. Dr. Martha Radike (who was a wonderful friend and colleague) did this study back in the early 1980s, but I don’t believe she ever published the results.  This particular animal (M8029) inhaled 600 ppm vinyl chloride 5 days a week for a year. The specifics of this which I cant remember (30 years ago) are 600 mmp VC, 4 hours a day, 5 days a week for a year, and this particular animal received 2-10 mg of vitamin C per day.  The mitochondria in lung, btw, were also very enlarged, though at this point I did not see any of these little inclusions within the mitochondrial membrane.

guinea_pig_liver_mitochondrion_vinyl_chloride_low_vit_CPublished reports have described changes from vinyl chloride exposure in liver: hypertrophy and hyperplasia of hepatocytes, activation and hyperplasia of sinusoidal lining cells, fibrosis of the portal tracts and the septa and intralobular perisinusoidal regions, sinusoidal dilation, and focal areas of hepatocellular degeneration. While the latter came out of a document that said DO NOT REFERENCE DO NOT QUOTE (oh well, excuse me), these are separate observations, but supportive of the unusual changes that Martha Radike (and I) found as mitochondrial changes seen in liver her year-long vinyl chloride exposure experiments in guinea pigs. There is a single mitochondrion pictured here, and two enlargements of areas (red boxes designate insets) which show the most wonderful inclusions I’ve seen twixt the outer mitochondrial membrane and inner mitochondrial membrane (I guess I could look for it in the intra-cristal membrane too but I haven’t yet). There are some misshapen mitochondria with cristae showing such in the air-breathing controls, which I will post, that received higher doses of vitamin C.  One wonders if the health of the entire colony played more into the results of all these changes (lung and liver both).

These little lollypops stuck on either side of the membrane are neatly alternating in a wonderful order and speak to something that I have not investigated but which was immediately apparent when I did googled “lollipops and inner mitochondria membrane” this may be ATP synthase. The dimensions are close to a reference I found: Structure of the mitochondrial ATP synthase by electron cryomicroscopy  by John L. Rubinstein, John E. Walker, and Richard Henderson.  There are some great videos on this molecular machine: HERE and HERE and HEREATP_synthaseIn the bottom section of the top micrographs the RED dot is @27 nm (ribosome), green dot @ 18 nm, bar marker, 100 nm. In the small bottom image i just cut and pasted two visuals of ATP synthase onto an enlarged portion of the above micrograph.  I added two charts to the pdf uploaded previously describing the materials and methods for vinyl chloride exposure. Find that document –> vinyl_chloride_vit_C_guinea_pig_lung1.

Next post is going to be a few pix of the ribosome bundle which is adjacent to some of these portions of intramitochondrial membrane with ATP synthase strings.