Pneumocytes endoplasmic reticulum

Hackett and Sunderman 1968). Great enlargement of the nuclei and nucleoli was observed two to six days. The cytoplasm contained prominent arrays of rough endoplasmic reticulum, as well as increased numbers of free ribosomes and mitochondria. In some of the type 1 pneumocytes, the endoplasmic reticulum was distended with flocculent osmiophiUc material. Abundant Golgi zones were present. Multivesicular bodies were found two and four days after Ni(CO)4 appUcation. They were usually surrounded by a single membrane. 

Intracellular macrophage inflammatory protein-2 was found mainly in the endoplasmic reticulum of primary cultured rat pneumocytes in response to lipopolysaccharide stimulation (Xavier et al. 1999). The amount of MIP-2 produced in these cells is at a magnitude similar to that from macrophages. Its production in rat pneumoctes is regulated at... 

Acid phosphatase (EC 3.1.3.2) was chiefly found in the characteristic laminated vacuoles of the type II pneumocytes of the rat (Corrin et al. 1969). Not all such vacuoles nor indeed all such cells contained the enzyme but in many, acid phosphatase reaction product formed a thin rim about the periphery of the vacuoles. The enzyme was not limited to the smaller of these cytosomes and was often present in the larger and presumably older vacuoles. Occasionally reaction product was aligned alongside or within channels of the endoplasmic reticulum. The multivesicular bodies described by Sorokin (1966) and Goldenberg et al. (1967) generally contained acid phosphatase at their periphery and between the individual vesicles. 

Fig. 102. Conspicuous dilatation of the rough endoplasmic reticulum cisternae in a type II pneumocyte of a 228 g female rat (breeder Winkehnann, Borchen-Kirchborchen) 30 min after a subcutaneous injection of 1 mg pilocarpine HCl per kg body weight. Fixed under methitural anaesthesia by intratracheal instillation of 2.5 % glutarmdehyde in phosphate buffer (pH 7.4) before opening the thorax. Postfixation with 1 % osmium tetroxide in phosphate buffer (pH 7.4). Contrasted en bloc for 12 h with 0.5 % uranyl acetate in 70% ethanol. Embedded in a 2 8 mixture of methyl and butyl methacrylate. Sectioned at 50 nm. Lead citrate after Reynolds (1963). Plate 26/06...

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