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PubMed1993

Cysteamine gliopathy in situ: a cellular stress model for the biogenesis of astrocytic inclusions.

In cultured astroglia, cysteamine induces the accumulation of peroxidase-positive cytoplasmic inclusions in the context of a generalized cellular stress response. In the present study, systemic cysteamine administration over a 3 week period induced HSP27, 72, 90, and GRP94 (stress proteins) in astrocytes and significantly increased numbers of peroxidase-positive astrocytic inclusions in the various brain regions relative to controls. Similar patterns of HSP expression were also observed at 24 hours following cysteamine treatment indicating that cellular stress may be a very proximal event in the biogenesis of the astrocytic inclusions. The topography of glial peroxidase activity may provide a "map" of central nervous system regions particularly prone to oxidative stress during normal aging and under pathologic conditions.

Animals↗
PubMedDate not supplied

[The modification of the radiation damage to the chromosomes in the somatic cells of radiosensitive Drosophila mutants. The radioprotective action of cysteamine].

The radioprotective effect of cysteamine has been studied in larva nerve ganglia of the radiosensitive mutant rad(20)201G1, mutagen-sensitive mutant mus(2)201G1 and the control strain of drosophila. Cysteamine was shown to produce a radioprotective effect in somatic cells of mus(2)201G1 and the control strain of drosophila which was manifested by the decreased incidence of cells with chromosome aberrations and diminished yield of deletions and exchanges. No significant radioprotective effect of cysteamine was observed in somatic cells of rad(2)201G1 mutant.

Animals↗
PubMed1996

Brain somatostatin depletion by cysteamine attenuates the penile erection induced by serotonergic and dopaminergic, but not by cholinergic, activation in rats.

To clarify the role of brain somatostatin in the expression of penile erection, the effects of cysteamine, a somatostatin depletor, on the penile erection induced by serotonergic, cholinergic and dopaminergic stimulants were investigated in rats. Fenfluramine (0.1-10 mg/kg, i.p.), pilocarpine (0.032-3.2 mg/kg, i.p.) and apomorphine (0.01-1 mg/kg, i.p.) induced penile erection in rats, with bell-shaped dose-response curves. Pretreatment with cysteamine (200 mg/kg, s.c.) significantly attenuated the penile erection induced by fenfluramine and apomorphine, but scarcely affected that induced by pilocarpine. Neurochemical measures revealed that cysteamine pretreatment significantly reduced the somatostatin content in all brain regions examined. These results provide the first pharmacological evidence that the brain somatostatin may play an important role in drug-induced penile erection.

Animals↗
PubMed1976

The influence of the known radioprotective compounds on the metabolism of human red blood cell. Part II. The influence of cysteamine on enzymic systems.

The influence of cysteamine on the metabolic activity of red blood cells has been estimated in vitro. Cysteamine has a marked influence on the activity of mainly aldolase F-1, 6-P and glucose-6-P dehydrogenase in red blood cells in vitro. The anaerobic metabolism of erythrocytes is more active in the presence of lower doses of cysteamine. Higher concentrations of radioprotector stimulate the pentose phosphate shunt.

Anaerobiosis↗
PubMed1994

Induction of resistance to melarsenoxide cysteamine (Mel Cy) in Trypanosoma brucei brucei.

A population of Trypanosoma brucei brucei with reduced sensitivity to melarsenoxide cysteamine (Mel Cy) was produced in immunosuppresed mice using subcurative drug treatment. Melarsenoxide cysteamine resistance was stable after cyclical transmission through Glossina morsitans centralis. In vitro, the blood-stream forms showed 15-fold higher values for the minimal inhibitory concentration as compared with the parental clone. Cross-resistance could be determined with another arsenical drug, melarsoprol (14-fold) and to two different diamidines (diminazene aceturate: 47-fold; pentamidine methanesulphonate: 34-fold), but not to suramin. When cells were transformed to procyclic forms and tested in vitro, the sensitivity of the resistant population to melarsenoxide cysteamine was only 6-fold lower than that of the parent, but comparatively high cross-resistance could be shown to other drugs (melarsoprol; 85-fold; pentamidine methanesulphonate: 17-fold; quinapyramine sulphate: 40-fold). Selection of the resistant trypanosomes from non-resistant ones was possible under pentamidine methanesulphonate pressure in cell culture.

Animals↗
PubMed1998

Oxidation of cysteamine induced by gas-phase radicals from combustion smoke of poly (methyl methacrylate).

In order to obtain fundamental knowledge on biological damage caused by the smoke from combustion of poly(methyl-methacrylate) (PMMA), we investigated the oxidation of cysteamine induced by PMMA smoke. We suggest that the long-lived and oxygen-centered radicals involved in PMMA smoke should play an important role in the oxidation of cysteamine. The mechanism for the oxidation of cysteamine by combustion smoke of PMMA was postulated as radical initiated chain reactions, taking into account the effect of pH, oxygen and radical concentrations.

Chromatography, High Pressure Liquid↗
PubMed1990

A randomized placebo-controlled trial of cysteamine eye drops in nephropathic cystinosis.

Eighteen patients with nephropathic cystinosis who were younger than 42 months and 11 patients 4 to 31 years of age were entered into a double-masked, randomized, placebo-controlled trial of topical cysteamine eye drops between November 1985 and September 1989. Eight of the younger patients and 2 of the older patients showed marked clearing of corneal crystals in one eye compared with the fellow eye. When the code was broken, all 10 patients were found to have received cysteamine eye drops in the improved eye. Of the remaining 19 patients 4 were unavailable for follow-up. In 15 patients no marked difference was noted between the two eyes. Eight have presumably been in the protocol for too short a time and several have been poor compliers with the therapy. These results not only demonstrate the potential for primary prevention of corneal crystal deposition but also, for the first time, offer the possibility of reversing the corneal complications of cystinosis in older patients.

Adolescent↗
PubMed1996

Endogenous zinc concentrations in cysteamine-induced duodenal ulcers in the rat.

Exogenously administered zinc compounds have been shown to possess anti-ulcer activity against a wide variety of ulcerogenic agents, both in laboratory animal models and in human peptic ulcer disease. However, a strong possibility exists that endogenous zinc may also play an important role during noxious events by various mechanisms. Therefore, the aim of this study was to focus on the changes of endogenous zinc serum and tissue concentrations in cysteamine-induced duodenal lesions. We used atomic absorption spectrophotometry to determine the tissue and serum concentrations of zinc in normal (control) rats and those with cysteamine-induced duodenal ulcers. The results obtained in this study indicated that the onset, development and spontaneous healing of ulcer lesions were associated with certain shifts in zinc serum and tissue concentrations. Prior to ulcer formation, a significant increase was noted in serum zinc values. With the onset of duodenal lesions, zinc serum concentrations significantly decreased, while there was a significant increase in duodenal tissue concentrations when compared to healthy control animals. Zinc tissue concentrations decreased and returned to starting values by the end of the first week of spontaneous healing. This decrease in zinc tissue concentration corresponded to the healing rate of the duodenal ulcers. Serum zinc concentrations also returned to starting values within the first week period. These observations indicate and confirm that zinc could play an important role in duodenal ulcer disease and represent a natural defense system in the body.

Animals↗
PubMed1994

Phase advances of circadian rhythms in somatostatin depleted rats: effects of cysteamine on rhythms of locomotor activity and electrical discharge of the suprachiasmatic nucleus.

Somatostatin is synthesized in the suprachiasmatic nucleus (SCN), a circadian pacemaker in mammals. To explore the functional significance of somatostatin in the circadian system, we examined rhythms of rat locomotor activity and electrical firing rate of SCN neurons in the brain slice after temporal depletion of somatostatin levels in the SCN. Intraperitoneal administration of cysteamine (200 mg/kg), a somatostatin depletor, significantly reduced somatostatin level in the in vivo SCN 5 min after injection and kept low level as long as 3 to 4 days. This administration, on the other hand, induced significant phase advances of about 51 min in the subsequent free-running rhythm of locomotor activity of the rat. A marked phase advance in the circadian rhythm of firing rate in the SCN was also observed after administration of cysteamine in coronal hypothalamic slices. These persistent phase shifts after administration of a somatostatin depletor may suggest that the change of somatostatin level in the SCN have a feedback influence on the circadian pacemaker.

Animals↗
PubMed1995

Modulation of bleomycin-induced mitotic recombination in yeast by the aminothiols cysteamine and WR-1065.

The cancer chemotherapy drug bleomycin (BLM) is a potent inducer of genetic damage in a wide variety of assays. The radioprotectors cysteamine (CSM) and WR-1065 have been shown in previous studies to potentiate the induction of micronuclei and chromosome aberrations by BLM in Go human lymphocytes. By contrast, WR-1065 is reported to reduce the induction of hprt mutations by BLM in Chinese hamster cells. To elucidate the basis for these interactions, we examined the effects of CSM and WR-1065 on the induction of mitotic gene conversion by BLM in the yeast Saccharomyces cerevisiae. Treatment with BLM causes a dose-dependent increase in the frequency of mitotic gene conversion and gene mutations. Unlike its potentiation of BLM in Go lymphocytes, WR-1065 protected against the recombinagenicity of BLM in yeast. CSM was also strongly-antirecombinagenic under, some conditions, but the nature of the interaction depended strongly on the treatment conditions. Under hypoxic conditions, cysteamine protected against BLM, but under oxygen-rich conditions CSM potentiated the genetic activity of BLM. The protective effect of aminothiols against BLM may be ascribed to the depletion of oxygen required for the activation of BLM and the processing of BLM-induced damage. Aminothiols may potentiate the effect of BLM by acting as an electron source for the activation of BLM and/or by causing conformational alterations that make DNA more accessible to BLM. The results indicate that aminothiols have a strong modulating influence on the genotoxicity of BLM in yeast as they do in other genetic assays. Moreover, the modulation differs markedly depending on physiological conditions. Thus, yeast assays help to explain why aminothiols have been observed to potentiate BLM in some genetic systems and to protect against it in others.

Alleles↗
PubMed1980

Synergistic action of cysteamine and BrdU-substituted DNA in the induction of sister chromatid exchanges.

The effect of different BrdU-concentrations on the cysteamine-induced SCE-rate was investigated in V-79 Chinese hamster cell monolayer cultures. Both cysteamine and its auto-oxidation product cystamine act synergistically with BrdU in the induction of SCEs. A given concentration of these substances produces a low SCE-frequency at low BrdU-concentrations -- but the incidence of SCEs is significantly increased at increased BrdU-concentrations. -- Using one-cycle substitution experiments and the determination of the relative level of substitution by means of 3HBrdU-incorporation, this synergism was shown to depend on the BrdU incorporated in the DNA and on the extent to which this incorporation takes place.

Animals↗
PubMed1988

Autoradiographic study on healing process of cysteamine-induced duodenal ulcer in rat. Possible importance of Brunner's glands in ulcer healing.

The healing process of cysteamine-induced duodenal ulcer was studied by [3H]thymidine autoradiography. After the development of ulcer in the duodenum, cell proliferation was markedly activated not only in the crypts but also in the Brunner's glands near the ulcer. In the initial stages of ulcer healing, they both contributed to form the surface covering regenerating epithelium. Granulation tissue also proliferated at the base of the ulcer. In later stages of ulcer healing, new crypts were formed in the floor of the ulcer. New villi regenerated from these crypts and Brunner's glands regenerated by proliferation in situ. The ulcer base then was completely covered with new villi and granulation tissue was replaced by dense fibrous connective tissue. The present study suggested that the Brunner's glands, together with the crypts of Lieberkühn, play an important role in the healing process of cysteamine-induced duodenal ulcer.

Animals↗
PubMed1989

Effect of duodenal ulcerogens cysteamine, mepirizole, and MPTP on duodenal myoelectric activity in rats.

Increased gastric acid secretion, enhanced acid delivery to the duodenum, and reduced alkaline secretion in the proximal duodenum are relatively well-established pathophysiologic abnormalities in duodenal ulcer. Impaired duodenal motility, however, may also contribute to duodenal ulceration by altering the distribution of acid and alkaline secretions along the upper digestive tract. We tested the hypothesis that the duodenal ulcerogens cysteamine, MPTP, and mepirizole modify duodenal motility in the rat and that motility changes might be a common and early alteration in experimental duodenal ulceration. All three duodenal ulcerogens rapidly produced extensive changes in duodenal myoelectric activity and reduced the frequency of myoelectric slow waves. Cysteamine induced marked hypermotility for at least 6 hr; MPTP rapidly decreased motility and fragmented the myoelectric migrating pattern. Mepirizole induced biphasic changes: an early hypermotility phase of about 30 min was followed by profound hypomotility. These results indicate that marked alterations of duodenal motility are common during experimental duodenal ulceration. In light of the differential effect of the ulcerogens on duodenal motility, it remains to be determined how these changes influence acid neutralization in the proximal duodenum. Nevertheless, our results suggest that all three duodenal ulcerogens, which are different in structure, alter duodenal motility.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1989

Augmentation of cysteamine-induced ulceration of rat duodenum by systemically administered gamma-aminobutyric acid (GABA).

Subcutaneous administration of a single dose of gamma-aminobutyric acid (GABA, 10 mg/100 g) in conjunction with a pretreatment dose of aminooxyacetic acid (AOAA 2.5 mg/100 g subcutaneously) to prevent the degradation of GABA, significantly augmented the incidence and intensity of cysteamine HCl-induced duodenal ulceration in rats. This effect of GABA could be reduced by the GABA receptor antagonist, bicuculline (30 micrograms/100 g subcutaneously). These results suggest peripheral GABA receptors can modulate cysteamine HCl-induced duodenal ulcer.

Aminooxyacetic Acid↗
PubMed1996

Clinical polymorphism of cystinosis encephalopathy. Results of treatment with cysteamine.

Of the 26 cystinotic patients over 19 years of age followed in our institution, 7 developed CNS complications at a mean age of 23 years. Two forms were observed. The first, associating cerebellar and pyramidal signs, mental deterioration and finally pseudo-bulbar palsy, may be called cystinosis encephalopathy. The other form resembled a stroke-like episode with coma and hemiplegia or milder symptoms. Hydrocephalus was rare and not associated with clinical symptoms in this series. Cysteamine was administered for longer than 6 months to 4 of the patients with encephalopathy. Two had an almost complete disappearance of their symptoms including the gross abnormalities of MR imaging in one; one improved partially and remained stable, and one continued to deteriorate but was suspected of non-compliance. These results suggest that cysteamine may be an effective treatment of cystinosis encephalopathy and encourage prescription of this drug in cystinosis in order to prevent this complication.

Adolescent↗
PubMed1983

Handling of L-[35S]cystine by cysteamine-pretreated cystinotic and normal fibroblasts.

In short incubations with 0.1 mM L-[35S]cystine in phosphate-buffered saline medium, and long incubations with label in complete minimum Eagle's medium with Earle salts, cystine-depleted cystinotic cells reaccumulate labeled cystine more rapidly than pretreated normal cells. Cysteamine pretreatment of both normal and cystinotic cells resulted in an initial increased conversion of exogenous cystine to intracellular cysteine. In 24-h incubations in complete medium, cysteamine-pretreated cells showed enhanced conversion of 0.1 mM L-[35S]cystine to cysteine and reduced glutathione. Addition of cycloheximide to the incubation media decreased the incorporation of 35S into cellular protein by more than 90% but did not affect the accumulation of intracellular labeled cystine in cystinotic cells. Therefore, the incorporation and release of cystine from protein is not an obligatory source of accumulated cystine and we speculate that there may be early extralysosomal entrapment of cystine in cystinotic cells.

Cell Line↗
PubMed1988

Palmitoyl derivatives of L-cysteine, cysteamine, L-cystine, cystamine and their incorporation into the bilayers of unilamellar liposomes.

The amino groups of the amino acids L-cysteine and L-cystine as well as their biogene amines cysteamine and cystamine were derivatized with palmitoyl residues. The obtained lipophilic R-SH and R-S-S-R components were incorporated into the bilayers of unilamellar liposomes. The resulting liposomes carrying about 2000 functional groups each remained stable and homogeneous during 60 days after incorporation of N-palmitoyl cysteamine and N,N'-dipalmitoyl cystamine. The incorporation of the lipophilic amino acid derivatives, however, destabilized the resulting liposomes. Via the thiol residues of the functionalized liposomes activated molecules can be linked to the liposomal surface by disulfide bonds.

Amino Acids↗
PubMed1986

Somatostatin, insulin and glucagon secretion by the perfused pancreas from the cysteamine-treated rat.

In rats, administration of a single dose of cysteamine (300 mg/kg, intragastrically) induces a depletion of pancreatic somatostatin content (approximately 60%) without modifying pancreatic insulin or glucagon content. In perfused pancreases from cysteamine-treated rats, there was a lack of somatostatin response to glucose, arginine or tolbutamide. In the absence of stimulated somatostatin release, the secretory responses of insulin and glucagon to glucose, to arginine, and to tolbutamide were not significantly different from those observed in pancreases from control rats. Our data do not support the concept that pancreatic somatostatin plays a major role in the control of insulin and glucagon release.

Animals↗