Subcellular structure of bovine thyroid gland. A study on bovine thyroid membranes by buoyant-density-gradient centrifugation in a B-XIV zonal rotor.
A combined mitochondrial and light mitochondrial fraction and a microsomal fraction were isolated from bovine thyroid gland and fractionated further in a B-XIV zonal rotor. A density gradient ranging from 20 to 50% (w/w) sucrose was used. The rotor was operated for 3 h at 45 000 rev./min. All manipulations were performed at 4 degrees C and at pH 7.4. 2. Membranous material was recovered in two zones: zone I, containing microsomal material derived from both smooth endoplasmic reticulum and plasma membranes and probably also from other smooth membranes; zone II, containing material from rough endoplasmic reticulum. 3. Increasing the pH of the medium up to 8.6, or the addition of Mg2+ to the medium resulted in the formation of a single zone at intermediate densities (aggregation of membranes?). An analogous effect was obtained after treatment with Pb (NO3) 2. 4. In the presence of heparin (50 i.u./ml) the bulk of the membranes was found in zone I. This was due to the release of ribosomes from the rough endoplasmic reticulum.
D000135:Acid Phosphatase / Q000032:analysis; D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D002417:Cattle; D002501:Centrifugation, Zonal; D002784:Cholesterol / Q000032:analysis; D004072:Digitonin / Q000494:pharmacology; D003576:Electron Transport Complex IV / Q000032:analysis; D005952:Glucose-6-Phosphatase / Q000032:analysis; D005959:Glucosidases / Q000032:analysis; D006493:Heparin / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D008566:Membranes / Q000032:analysis; D008861:Microsomes / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D009251:NADPH-Ferrihemoprotein Reductase / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D011506:Proteins / Q000032:analysis; D012794:Sialic Acids / Q000032:analysis; D013961:Thyroid Gland / Q000032:analysis / Q000648:ultrastructure*
D010743:Phospholipids; D011506:Proteins; D012794:Sialic Acids; D006493:Heparin; D002784:Cholesterol; D009251:NADPH-Ferrihemoprotein Reductase; D003576:Electron Transport Complex IV; D000135:Acid Phosphatase; D005952:Glucose-6-Phosphatase; D005959:Glucosidases; D000251:Adenosine Triphosphatases; D008274:Magnesium; D004072:Digitonin