Goglia F, Liverini G, Lanni A, Iossa S, Barletta A
Dipartimento di Fisiologia Generale ed Ambientale, Università di Napoli, Italy.
Exp Biol. 1989;48(3):127-33.
A report is made (during cold exposure) of: a) the morphometric-stereologic analysis both on the whole rat liver peroxisomal population, and on 2 peroxisomal subpopulations having a diameter greater than 0.5 microns, and less than 0.5 microns, called Pe (Peroxisomes) and sPe (small Peroxisomes), respectively; b) the uricase and palmitoyl-coenzyme A oxidase activity assay on 2 classes of rat liver peroxisomes, sedimenting at 10,000 g and 27,000 g and containing Pe and sPe, respectively. The peroxisomal volume and number densities increase during cold exposure, reaching a maximum (+67% and +130%, respectively, P less than 0.05) at 10 days. These modifications are accompanied by an appreciable reduction of the average peroxisome volume (from 0.27 +/- 0.05 microns 3 to 0.19 +/- 0.02 microns 3) due to a major percentage increase of sPe during cold exposure. At a qualitative level, the formation of "clusters" and a stricter association between mitochondria and peroxisomes is also observed. Cold exposure increases the oxidative capacity of the whole peroxisomal compartment; in the Pe fraction the palmitoyl-CoA oxidase and uricase specific activity ratio is constant (about 0.1), during cold exposure, but in the sPe fraction this ratio increases significantly (from 0.05 to 0.09). The results indicate that the peroxisomal population is influenced during cold exposure, with the formation of a new peroxisomal population which is on average smaller and more specialized for the beta-oxidative activity. The possible involvement of peroxisomes in thermoregulatory thermogenesis during cold exposure is also discussed.
（在冷暴露期间）报告了以下内容：a）对整个大鼠肝脏过氧化物酶体群体以及对直径大于0.5微米和小于0.5微米的2个过氧化物酶体亚群体进行形态计量学-立体学分析，这两个亚群体分别称为Pe（过氧化物酶体）和sPe（小过氧化物酶体）；b）对大鼠肝脏过氧化物酶体的2类进行尿酸酶和棕榈酰辅酶A氧化酶活性测定，这2类过氧化物酶体分别在10,000 g和27,000 g下沉淀，且分别含有Pe和sPe。在冷暴露期间，过氧化物酶体的体积和数量密度增加，在第10天达到最大值（分别为+67%和+130%，P<0.05）。这些变化伴随着平均过氧化物酶体体积的明显减小（从0.27±0.05立方微米降至0.19±0.02立方微米），这是由于冷暴露期间sPe的百分比大幅增加。在定性水平上，还观察到“簇”的形成以及线粒体与过氧化物酶体之间更紧密的关联。冷暴露增加了整个过氧化物酶体区室的氧化能力；在Pe组分中，冷暴露期间棕榈酰辅酶A氧化酶和尿酸酶的比活性保持恒定（约为0.1），但在sPe组分中该比值显著增加（从0.05增至0.09）。结果表明，过氧化物酶体群体在冷暴露期间受到影响，形成了一个新的过氧化物酶体群体，其平均尺寸较小且更专门用于β氧化活性。还讨论了过氧化物酶体在冷暴露期间参与体温调节性产热的可能性。
