A study of kidney lysosomal acid phosphatase during compensatory renal hyperplasia in rats

1968 ◽  
Vol 46 (3) ◽  
pp. 499-502 ◽  
Author(s):  
B. M. Hegdekar

Female rats of the Long-Evans hooded strain, 4–6 months old and weighing 275–300 grams, were subjected to unilateral nephrectomy and the acid phosphatase activity in the remaining kidney was studied at the end of 24, 48, 72 hours, and 8 days respectively. Most of the acid phosphatase was found in the particulate fraction in normal kidneys. The enzyme activity in the soluble fraction was found to have increased the second day after the operation, but decreased to the original level by the end of 72 hours. The free activity of the lysosomal fraction also increased by the end of second postoperative day. A change in the permeability of the lysosomal membrane before the enzyme release was observed. The probable role of lysosomal enzymes in the initiation of mitotic divisions during compensatory renal hyperplasia is discussed.

Author(s):  
N.J. Unakar ◽  
J. Tsui ◽  
J.R. Reddan

Lysosomal enzymes seem to play an important role in wound healing and tissue repair (1,2, and 3). In the present investigation we have shown the existence of acid phosphatase and lysosomes in lenticular tissue and have examined the probable role of this enzyme in the induction of galactose cataract. Experiments were performed on Sprague-Dawley rats (50g) fed for 4 days on a diet consisting of equal proportions (by wt.) of Purina Rat Chow and D-galactose. Animals fed Purina Rat Chow alone served as controls. Acid phosphatase was localized by two separate procedures (4 and 5). Lenses were processed for electron microscopy as previously described (3). Lenticular tissue of both controls (Figs. 1 and 2) and galactose fed animals exhibits the reaction product of acid phosphatase. However, the group fed galactose showed a much stronger reaction product compared to controls.


1980 ◽  
Vol 58 (5) ◽  
pp. 403-409 ◽  
Author(s):  
D. C. S. Hutchison ◽  
R. Desai ◽  
D. Bellamy ◽  
H. Baum

1. The lysosomal enzymes of circulating polymorphonuclear leucocytes contain a potent elastase; release of this enzyme within the lung is thought to be responsible for the destruction of elastic tissue in pulmonary emphysema. 2. The release of lysosomal enzymes from blood leucocytes of normal and emphysematous subjects during phagocytosis of particulate material was studied In vitro. Acid phosphatase and acid ribonuclease were used as markers of lysosomal enzyme release, no sufficiently sensitive assay for elastase being available. Cigarette smoke was separated into ‘particulate’ and ‘soluble’ fractions. In a preliminary study, the particulate fraction stimulated enzyme release; in the experiments reported here, latex particles were used to produce this effect. 3. Approximately one-third of the total lysosomal enzyme content was released to the exterior of the cell during phagocytosis of latex particles. In this respect there was no difference between normal and emphysematous subjects. 4. The effects of the non-particulate soluble fraction of cigarette smoke on phagocytosis-induced enzyme release were studied. This fraction inhibited enzyme release from polymorphonuclear leucocytes of normal subjects but not from those of emphysematous patients. When the ‘cigarette-smoke solution’ was replaced by the respiratory inhibitor, antimycin A, a similar inhibition of enzyme release occurred. The inhibition of phagocytosis in cells of normal subjects is presumed to be due to a respiratory inhibitor such as carbon monoxide in the soluble fraction of the smoke. We postulate that the polymorphonuclear leucocytes of emphysematous patients are adapted to hypoxic conditions so that inhibition of enzyme release does not occur.


1980 ◽  
Vol 44 (1) ◽  
pp. 299-315
Author(s):  
R.M. McMillan ◽  
D.E. Macintyre ◽  
J.E. Beesley ◽  
J.L. Gordon

We have investigated the role in macrophage lysosomal enzyme release of arachidonate metabolites, extracellular divalent cations and cyclic AMP (cAMP) which modulate secretion in other cell types. Lysosomal enzyme secretion induced by zymosan was accompanied by release of malondialdehyde (MDA), which is derived from arachidonic acid via prostaglandin synthase. Blockade of MDA formation, by aspirin or indomethacin, was associated with only a small inhibitory effect on lysosomal enzyme release by zymosan: arachidonate metabolites thus play only a minor role in mediating macrophage lysosomal enzyme release. Zymosan-induced secretion of lysosomal enzymes from macrophages did not require extracellular magnesium or calcium although release was enhanced by magnesium and inhibited by calcium. These effects may be related to an influence of the ions on phagocytosis. Elevation of intracellular divalent cation concentrations, by ionophore A23187, induced release of lysosomal enzymes but this was a result of cell lysis. Adenylate cyclase stimulants and dibutyryl cAMP produced slight inhibition of zymosan-induced lysosomal enzyme release. Aminophylline and papaverine caused more marked inhibition but their effects may be due to actions independent of phosphodiesterase inhibition. Our data indicate that arachidonate metabolites and cAMP do not play a major role in regulating zymosan-induced enzyme release from macrophages. Extracellular calcium and magnesium may modulate secretion but the role of intracellular divalent cations remains to be established. We conclude that macrophage lysosomal enzyme secretion is controlled by regulatory mechanisms different from those which control similar degranulation processes in other cell types.


1988 ◽  
Vol 90 (1) ◽  
pp. 167-171
Author(s):  
A. TIEDTKE ◽  
L. RASMUSSEN ◽  
J. FLORIN-CHRISTENSEN ◽  
M. FLORIN-CHRISTENSEN

The ciliate Tetrahymena thermophila releases lysosomal enzymes into nutrient and starvation media. We show here that this process occurs selectively, i.e. without leakage of cytoplasmic components, as indicated by lack of release of isocitrate dehydrogenase, a cytosolic enzyme with high activity in Tetrahymena. The role of intracellular Ca2+ in the process was also investigated. The Ca2+ ionophore A23187 has strong stimulatory effects on this release. Ionophore stimulation is maximal in the presence of extracellular Ca2+ but can occur also in its absence. Quin 2 fluorescence measurements indicate that intracellular Ca2+ increases in both cases. Mg2+ completely prevents the stimulatory effects of A23187. Ionomycin, another Ca2+ ionophore, also stimulates lysosomal enzyme release with a maximal response in the presence of extracellular Ca2+. Measurements of extracellular isocitrate dehydrogenase showed that ionophore-stimulated lysosomal enzyme release can take place without leakage of cytoplasmic components. The observations that divalent cation ionophores stimulate selective lysosomal enzyme release and that this effect is strongest in the presence of external Ca2+ indicate that this cation plays a crucial role in the control of this process in Tetrahymena. Together with other observations they support the view that a subpopulation of Tetrahymena lysosomes has properties like those of secretory vesicles.


2020 ◽  
Vol 10 (11) ◽  
pp. 890
Author(s):  
Nitish Mittal ◽  
W. Todd Maddox ◽  
Timothy Schallert ◽  
Christine L. Duvauchelle

Ultrasonic vocalizations (USVs) are well-established markers of motivational and emotional status. Recent work from our lab has provided novel evidence for a role of USVs in models of ethanol (EtOH) use. For instance, USV acoustic characteristics can be used to accurately discriminate between rats selectively bred for high EtOH intake (e.g., alcohol-preferring (P) and high-alcohol-drinking (HAD)) versus EtOH-avoiding (e.g., alcohol-non-preferring (NP) and low-alcohol-drinking (LAD)) strains, as well as differentiate between male and female rats. In the present study we sought to explore the effect of age and alcohol availability on spontaneously emitted 50–55 kHz frequency modulated (FM) and 22–28 kHz USVs in adult, male Long–Evans rats. With the hypothesis that age and alcohol experience influence spontaneous USV emissions, we examined USV data collected across a 24-week intermittent EtOH access experiment in male Long–Evans rats. USV counts and acoustic characteristic (i.e., mean frequency, duration, bandwidth and power) data revealed distinct age-dependent phenotypes in both 50–55 kHz FM and 22–28 kHz USV transmission patterns that were modulated by EtOH exposure. These results highlight the influence of age and EtOH experience on the unique emotional phenotypes of male Long–Evans rats.


1979 ◽  
Vol 184 (2) ◽  
pp. 345-354 ◽  
Author(s):  
Wei Hsueh ◽  
Charles Kuhn ◽  
Philip Needleman

The phospholipids of rabbit alveolar macrophages were pulse-labelled with [14C]-arachidonic acid, and the subsequent release of labelled prostaglandins was measured. Resting macrophages released measurable amounts of arachidonic acid, the prostaglandins E2, D2 and F2α and 6-oxoprostaglandin F1α. Phagocytosis of zymosan increased the release of arachidonic acid and prostaglandins to 2.5 times the control value. In contrast, phagocytosis of inert latex particles had no effect on prostaglandin release. Indomethacin inhibited the release of prostaglandin, and, at high doses (20μg/ml), increased arachidonic acid release. Analysis of the cellular lipids showed that after zymosan stimulation the proportion of label was decreased in phosphatidylcholine, but not in other phospholipids or neutral lipids. Cytochalasin B, at a dose of 2μg/ml, inhibited the phagocytosis induced by zymosan but increased prostaglandin synthesis to 3.4 times the control. These data suggest that the stimulation of prostaglandin synthesis by zymosan is not dependent on phagocytosis. Exposure to zymosan also resulted in the release of the lysosomal enzyme, acid phosphatase. Furthermore, cytochalasin B augmented the zymosan-stimulated release of acid phosphatase at the same dose that stimulated prostaglandin synthesis. However, indomethacin, at a dose that completely inhibited prostaglandin synthesis, failed to block the lysosomal enzyme release. Thus despite some parallels between the release of prostaglandins and lysosomal enzymes, endogenous prostaglandins do not appear to mediate the release of lysosomal enzymes. The prostaglandins released from the macrophages may function as humoral substances affecting other cells.


1974 ◽  
Vol 62 (3) ◽  
pp. 625-634 ◽  
Author(s):  
John L. Skosey ◽  
Evelyn Damgaard ◽  
Donald Chow ◽  
Leif B. Sorensen

During the process of phagocytosis, polymorphonuclear leukocytes (PMN) release lysosomal enzymes into the extracellular medium. When the antibiotic cytochalasin B (CB) is present in the incubation medium along with phagocytable particles, enhanced recovery of enzyme activities from the incubation medium has been observed. These findings have led to the interpretation that CB enhances lysosomal enzyme release. Our results contradict this interpretation. The lysosomal enzymes acid phosphatase and ß-galactosidase are unstable after they are released from cells. During the first 5–15 min of phagocytosis, significant amounts of both acid phosphatase and ß-galactosidase can be recovered from the extracellular medium. After this, the recovery of enzyme from the medium declines, presumably because the rate of loss of lysosomal enzyme activity exceeds the rate of release at later time periods. In the presence of CB, the appearance of lysosomal enzymes in the extracellular medium of cells exposed to zymosan is retarded for 5–10 min, after which it begins and then continues for approximately 20 min. At the end of a 30-min incubation period, therefore, in the absence of CB, extracellular levels of lysosomal enzymes (especially those which are unstable) are declining toward low levels while, in the presence of CB, extracellular enzyme levels are continuing to rise. We also measured the lysosomal enzyme remaining within cells after exposure to zymosan. CB retarded the disappearance of enzyme from cells and resulted in significantly less total cell enzyme loss. Thus, in the presence of CB, a greater proportion of the lysosomal enzyme lost from cells is recovered in the extracellular medium. In contrast to the previous conclusions that CB enhances lysosomal enzyme release, our results indicate that CB delays and decreases the zymosan-stimulated release of lysosomal enzymes from PMN. Since CB inhibits phagocytosis by PMN, our results indicate that the antibiotic modifies the mechanism of release of lysosomal enzymes, resulting in zymosan stimulation of their release independently of phagocytosis.


1966 ◽  
Vol 14 (2) ◽  
pp. 135-146 ◽  
Author(s):  
J. C. H. DE MAN ◽  
A. P. R. BLOK ◽  
W. BEENS

The relation between agranular reticulum and glycogen was studied in hepatic cells of female rats. Prolonged fasting of nonadrenalectomized rats did hot result ins complete liver glycogen depletion, whereas in adrenalectomized rats this could be accomplished within a few hours of fasting. In nonadrenalectomized rats a marked development of agranular reticulum associated with glycogen was found, whereas in adrenalectomized rats no such marked development of agranular reticulum was seen during glycogen depletion. Early glycogen restoration in glycogen-depleted liver cells of adrenalectomized rats was brought about 2-4 hr after the injection of 1 dose of cortisone or ½-1 hr after the injection of glucose. Early restoration of glycogen was accompanied and even preceded by a marked development of tubular agranular reticulum. A probable role of this organelle in glycogen synthesis and breakdown is discussed. High resolution autoradiography of tritium-labeled glucose incorporation offered some further illustration on the process of glycogen formation.


Author(s):  
I.C. Murray

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.


Author(s):  
Randy Moore

Previous work has indicated that the graft incompatihility between Sedrmi telephoides and Solanum pennellil involves cell necrosis that results In a thick layer of collapsed cells at the graft Interface. This necrotic layer insulates the stock from the scion, which results in abscission of the Sedum scion after 4-6 weeks due to desiccation and starvation. Thus, cell autolysis (which is restricted to Sedum) characterizes the Incompatibility response in this system (1). In order to elucidate the events that lead to cell autolysis, and thus better understand the cellular site and mode of action of cellular incompatibility, the appearance and fate of the hydrolytlc enzyme acid phosphatase (AP) was followed in both the compatible Sedum autograft and the incompatible Sedum/Solanum heterograft. Acid phosphatase was localized by a modified Gomori-type reaction; positive (i.e., including NaF inhibitor) and negative (lacking substrate) controls showed no enzymatic precipitate. Following an initial association with the endoplasmic reticulum (ER) and dictyosomes at 6-10 hours after grafting, AP activity in the compatible Sedum autograft is associated primarily with the plasmalemma (Fig. 1). By 18-24 hours after grafting, the AP activity is restricted to the tono-plast and vacuole (Fig. 2). This strict compartmentation and absence of enzyme from the cytosol is maintained throughout the development of the compatible graft. While AP activity in the incompatible Sedum/Solanum heterograft is Initially similar to the compatible Sedum autograft (i.e., initially found on the ER and dictyosomes), there is a marked difference in enzyme localization in the two graft partners as the incompatibility response develops. As in the compatible autograft, Solanum cells at the graft interface show an Increase in AP activity that Is restricted to the vacuole and tonoplast, with little or no enzyme activity in the cytosol (Fig. 3). In comparable Sedum cells, however, there is a dramatic Increase In AP activity in the cytosol (Fig. h); this cytosollc AP activity is associated with thin fibril-like structures (Fig. 5) measuring approximately 60 A in diameter. This high cytoplasmic AP activity In Sedum cells results in cell autolysis, death, and eventual cell collapse to form the characteristic necrotic layer separating the two graft partners.


Sign in / Sign up

Export Citation Format

Share Document