Radiolabeled Colloid Uptake Distribution and Pulmonary Contents and Localization of Lysosomal Enzymes in Cholestatic Rats

Abstract

Studies of the activity uptake of radiolabelled 99mTc2S7 colloid in different tissues showed a moderately increased uptake in the lung 1 week and a greatly increased uptake 3 weeks after permanent bile duct occlusion. Three weeks after bile duct occlusion the activity uptake was also slightly increased in the spleen and moderately reduced in the liver. In pulmonary tissue of cholestatic rats, the levels of alkaline and acid phosphatase, beta-glucuronidase, and beta-hexosaminidase were determined after 6 weeks. The pulmonary contents of beta-glucuronidase was increased tenfold, and that of beta-hexosaminidase was increased fourfold in cholestasis. Histochemical investigation showed that the lysosomal enzymes were located in the macrophages, which in cholestasis were abundant in alveolar walls and inside alveoli. Macrophages were also frequently seen to engorge pulmonary veins.

Alterations of tumor necrosis factor‐alpha and interleukin 6 production and activity of the reticuloendothelial system in experimental obstructive jaundice in rats

“…Pain and Drives independently reported a diminution of the clearance ability of denaturated human albumins from the serum in about 50% of OJ patients [12,35]. These observations confirmed the data of Holmberg and Tanaka, who found a decrease of liver and spleen RES activity in long‐term experimental OJ and a simultaneous increase in RES activity in the lung [17,36]; Holman obtained similar results [25]. The cause of the decreased RES activity in OJ is not completely explained.…”

“…Together with humoral mechanisms, reticulo‐endothelial activity constitutes an integral part of the human defensive system [14,15]. Nearly 85–90% of macrophages are collected as the Kupffer cells in the venous sinusoids of the liver and spleen [16,17]. Reactivity of RES cells is reflected by their ability to produce mediators of the immune response such as TNF‐α, IL‐6, superoxide anion and nitric oxide and to phagocytose various particles, such as bacteria, immunological complexes, fibrinogen degradation products and endotoxins [3,14, 18–22].…”

Source of Increased Serum Beta-Hexosaminidase in Rat Liver Cirrhosis

“…Histochemically [4,5] the lyso somal enzymes were found to be increased in the hepatocytes as well as in the increased numbers of macrophages observed in the liv er, spleen and lungs during cholestasis. Prep arations of isolated hepatocytes and nonpa renchymal cells from the cholestatic rat livers showed increased specific activity of lyso somal enzymes in both cellular fractions [4].…”

Lysosomes and Human Liver Disease: A Biochemical and Immunohistochemical Study of -Hexosaminidase

“…From earlier o f high molecular mass. Via specific (mannose-6-phosstudies in humans and rats we küow that the lysosomal phate) receptors, most of these precursors are transenzyme, ß-hexosaminidase, 1 ) is increased in serum äs ported to the lysosomes, where they are subsequently well äs in liver and spieen tissue in cholestasis and cir-dephosphorylated and proteolytically processed to genrhosis (2)(3)(4)(5). In long Standing experimental cholestasis, erate lysosomally localized mature forms (7,8).…”

“…Genlysosomal enzymes are also increased in lungs, due to a erally, a small fraction (5-20%) of the newly syntheheavy accumulation of macrophages rieh in lysosomes s i ze d precursors is secreted (7). The lysosomal enzymes in alveoli and in pulmonary veins (4). In a retrospective f QU nd in serum are üi their precursor form (9).…”