Clinical evaluation of efficacy and tolerability of cysteamine 5% cream in comparison with tranexamic acid mesotherapy in subjects with melasma: a single-blind, randomized clinical trial study.

This study was aimed at evaluating the efficacy of Tranexamic Acid (TA) mesotherapy versus cysteamine 5% cream in the treatment of melasma. This single-blind, randomized clinical trial was conducted among 54 subjects between 2018 and 2019. Cysteamine 5% cream group was instructed to apply the cream on the melasma lesions 30 min before bed for 4 consecutive months. Conversely, 0.05 mL (4 mg/mL) TA mesotherapy was performed by a physician every 4 weeks until 2 months. The severity of melasma was evaluated using both Dermacatch® device and the modified Melasma Area Severity Index (mMASI). The most remarkable improvement rate was observed in the TA group at the third visit based on mMASI and Dermacatch® values at 47% and 15% in turn. The mMASI scores were substantially improved in both groups at the second visit (cysteamine vs TA 8.48 ± 2.34 and 7.03 ± 3.19; P = 0.359) and third visit (cysteamine vs TA 6.32 ± 2.11 and 5.52 ± 2.55; P = 0.952) as compared to baseline (cysteamine vs TA: 11.68 ± 2.70 and 10.43 ± 2.69). Dermacatch® values were significantly declined at the second and third visits (cysteamine vs TA 42.54 ± 12.84 and 38.75 ± 9.80, P = 0.365; 40.74 ± 12.61 and 36.17 ± 10.3, P = 0.123, respectively) compared with baseline (cysteamine vs TA 45.76 ± 13.41 and 42.41 ± 10.48), although the improvement rates between two groups were not significantly different. Findings suggest that none of the cysteamine and TA mesotherapy treatments measured by both mMASI and Dermacatch® methods have substantial advantages over the other; however, complications are less in the cysteamine than the TA mesotherapy group.

Influence of supplemented coated-cysteamine on morphology, apoptosis and oxidative stress status of gastrointestinal tract.

BACKGROUND: Cysteamine was coated to cover its odor and maintain the stability. However, coated cysteamine (CC) has not been clearly evaluated for its effects on the gastrointestinal mucosa status. We hypothesize that the appropriate CC supplementation in diet impacts the stomach and intestinal mucosa variously through regulating the morphology, apoptosis, and oxidative stress status in model of pigs. RESULTS: The results showed that villus height increased (P < 0.05), and crypt depth decreased (P < 0.05) in the ileum when pigs were fed the diet with low cysteamine (LCS) compared with the control diet. The ileal lesion score in the LCS group was significantly (P < 0.01) lower than that in the control group, while the gastric lesion score in the CC group was significantly (P < 0.01) higher compared with that of the control group. It also showed that the activities of total superoxide dismutase (T-SOD) and diamine oxidase (DAO) were upregulated (P < 0.05) in the LCS group. In addition, Bax and caspase 3 immunore-activity increased (P < 0.01), and Bcl-2 immunoreactivity decreased (P < 0.01) in the gastric mucosa of pigs fed the diet with high cysteamine (HCS). The Bax and caspase 3 immunoreactivity decreased (P < 0.01), and Bcl-2 immunoreactivity increased (P < 0.01) in ileum mucosa of pigs fed the HCS diet. CONCLUSIONS: Although moderate dietary coated cysteamine showed positive effects on GI mucosal morphology, apoptosis, and oxidative stress status, the excess coated cysteamine may cause apoptosis leading to GI damage in pigs.

The effect of food and liquid pH on the integrity of enteric-coated beads from cysteamine bitartrate delayed-release capsules.

BACKGROUND: Cysteamine bitartrate delayed-release (DR) capsule (Procysbi®) is approved for treatment of nephropathic cystinosis in the USA, Canada, and the EU. The capsules contain cysteamine bitartrate beads that are enteric coated with acid-resistant Eudragit L 30 D-55, preventing drug release in the acidic stomach environment while allowing dissolution of the beads in the more alkaline environment of the small intestine. Patients who have difficulty swallowing capsules can open capsules, sprinkle beads onto 4 ounces of a suitable food or liquid, gently mix, and consume the entire content within 30 minutes. Foods found to be suitable for administration, and described in the Procysbi US labeling, include fruit juices (except grapefruit juice), applesauce, and berry jelly; there are minor variations in the foods and liquids recommended by regulatory authorities in other countries. This study aimed to assess the stability of enteric-coated beads exposed to additional foods at different conditions to expand the list of suitable foods for drug administration. METHODS: For each test condition, beads from eight opened 75 mg cysteamine bitartrate DR capsules were gently mixed with test food and maintained at a prespecified temperature and duration; remaining undissolved beads were then recovered from the food. The recovered beads were split into two portions: one assayed for remaining drug content and the other subjected to dissolution testing to assess the effect on the drug-release profile. RESULTS: The results show that bead integrity was maintained when mixed with foods at pH values <5.5 at all time points when refrigerated (2°C-8°C) and at room (20°C-22°C) and lukewarm (37°C-41°C) temperatures. Bead integrity was not maintained when mixed with foods at pH values of ≥5.5 at room temperature. CONCLUSION: The results from this in vitro dissolution study help in identifying additional foods that may be used for the administration of cysteamine bitartrate DR beads from opened capsules using the sprinkle method.

Novel approaches for improving stability of cysteamine formulations.

Cystinosis is a genetic disorder that leads to the formation of cystine crystals in many organs in the body including cornea. Ocular manifestation of this disease is treated by eye drops of cysteamine which can easily oxidize into its disulfide cystamine. The rapid oxidation limits the shelf life as well the duration during which the drug can be used after opening the eye drop bottle. We evaluate two approaches of preventing the oxidation of cysteamine with the goal of increasing the time of use after opening the bottle to one month. The first approach integrates antioxidants such as catalase enzyme and vitamins C and E into the aqueous solution. Results show that catalase is the most effective additive as it decreases the oxidation rate by 58%, which on its own is not sufficient to reach targeted one month stability. The second approach focuses on incorporating diffusion barriers to prevent oxygen from reaching the cysteamine solution. This was accomplished by two methods: formulation of a hydrophobic layer which floats on the surface of the aqueous solution and integration of OMAC® oxygen-resistant material into the eye drop bottle. Both methods delay the onset of cysteamine degradation and decrease the rate of degradation. In particular, an eye drop bottle with three layers of OMAC® has less than 10% degradation after one month of opening the bottle and withdrawing a drop each day. By integrating all three methods, we designed a system where >90% of cysteamine remains in the active form for 70 days after opening the bottle. In addition, we examine the use of OMAC® as heat-sealed pouches for storage of cysteamine eye drop bottles during packaging to eliminate the need for the current approach of freezing the formulation during shipping. The results show that such heat-sealed pouches would keep cysteamine stable for over one year at ambient conditions.

Effect of cysteamine hydrochloride supplementation on the growth performance, enterotoxic status, and glutathione turnover of broilers fed aflatoxin B1 contaminated diets.

This study aimed to investigate the effect of cysteamine hydrochloride (CSH) supplementation on the growth performance, opportunistic bacteria and enterotoxic markers, visceral lesions, glutathione turnover, and inflammatory factors of broilers fed diets contaminated with aflatoxin B1 (AFB1). One-day-old Arbor Acres broilers (n = 480) were randomly allocated to 4 treatments with 6 replicates of 20 chicks each for a 2 × 2 design with CSH (0 or 200 mg/kg) and AFB1 (0 or 40 µg/kg). The trial lasted for 42 d. Results showed that AFB1 negatively affected (P < 0.05) growth performance, opportunistic bacteria and enterotoxic markers, intestinal lesions, glutathione turnover, and inflammatory factors. The CSH increased (P < 0.05) feed intake and body weight gain. The enterotoxic status was relieved in the CSH treatments by reducing (P < 0.05) the populations of gut Escherichia coli, Gram-negative bacteria, serum diamine oxidase, and intestinal lesions. The CSH also increased (P < 0.05) serum reduced glutathione, glutathione s-transferases, and glutathione reductase, and decreased (P < 0.05) the mRNA levels of tumor necrosis factor-α, interleukin-6, and interleukin-1ß. Significant interactions (P < 0.05) were found on Gram-negative bacteria, diamine oxidase, and glutathione s-transferases. The results suggest that the CSH can improve glutathione turnover and reduce the risk of enterotoxic disease induced by AFB1 in broilers.

Effects of cysteamine supplementation on the intestinal expression of amino acid and peptide transporters and intestinal health in finishing pigs.

This study aimed to evaluate the effects of cysteamine supplementation on the expression of jejunal amino acid and peptide transporters and intestinal health in finishing pigs. Sixty barrows were allocated into two experimental diets consisting of a basal control diet supplemented with 0 or 142 mg/kg cysteamine. After 41 days, 10 pigs per treatment were slaughtered. The results showed that cysteamine supplementation increased the apparent digestibility of crude protein (CP) (P < 0.05) and the trypsin activity in jejunal digesta (P < 0.01). Cysteamine supplementation also increased the messenger RNA abundance of SLC7A7, SLC7A9 and SLC15A1, occludin, claudin-1 and zonula occludens protein-1 (P < 0.001) in the jejunum mucosa. Increased glutathione content (P < 0.01) and glutathione peroxidase activity (P < 0.05) and decreased malondialdehyde content (P < 0.01) were observed in pigs receiving cysteamine. Additionally, cysteamine supplementation increased the concentrations of secretory immunoglobulin A (IgA) (P < 0.05), IgM (P < 0.001) and IgG (P < 0.001) in the jejunal mucosa. It is concluded that cysteamine supplementation could influence protein digestion and absorption via increasing trypsin activity, enhancing the digestibility of CP, and promoting the expression of jejunal amino acid and peptide transporters. Moreover, cysteamine improved intestinal integrity, antioxidant capacity and immune function in the jejunum, which were beneficial for intestinal health.

Improving the cytoplasmic maturation of bovine oocytes matured in vitro with intracellular and/or extracellular antioxidants is not associated with increased rates of embryo development.

The production of reactive oxygen species (ROS) is a normal process that occurs in the cellular mitochondrial respiratory chain. However, an increase in ROS levels during in vitro production of bovine embryos induces oxidative stress, leading to failed embryonic development. Therefore, we investigated whether supplementation of IVM medium with intracellular (cysteine and cysteamine; C + C) and/or extracellular (catalase; CAT) antioxidants improves the culture system, affects the mitochondrial membrane potential, affects the intracellular levels of ROS and glutathione (GSH) in the bovine oocytes at the end of maturation, and thereby affects the subsequent embryonic development. At the end of IVM, the metaphase II rates were unaffected by the treatments (76.7 ± 1.7% to 80.6 ± 5.2%; P > 0.05). The intracellular ROS levels, expressed in arbitrary fluorescence units, found in the oocytes treated with intracellular antioxidants (C + C and C + C + CAT groups; 1.06, averaged) were as low as those observed in immature oocytes (0 hour: 1.00 ± 0.12). Among mature oocytes, higher (P < 0.05) ROS levels were found in the control group (1.91 ± 0.10) when compared to the ROS levels found in oocytes treated with antioxidants. Intracellular GSH levels in all groups were lower (0.17 ± 0.09 to 0.51 ± 0.05; P < 0.05) than those in immature oocytes (1.00 ± 0.08), although GSH levels in the C + C group (0.51 ± 0.05) were greater (P < 0.05) than in the control, CAT, and C + C + CAT groups (0.23; averaged). The mitochondrial membrane potential in all groups was improved (1.6; averaged; P < 0.05) compared to the membrane potential observed in the immature oocytes (1.00 ± 0.05), with the exception of the C + C group (0.94 ± 0.03). There was no effect (P > 0.05) of antioxidant supplementation on embryonic development to the blastocyst stage (36.1%; averaged); however, there was an increased tendency (P = 0.0689) to obtain a higher blastocyst rate for the C + C + CAT group (47.5 ± 5.6%) compared to the control group (29.9 ± 4.8%). In conclusion, despite improvements in specific parameters of cytoplasmic maturation, the addition of intracellular and/or extracellular antioxidants during IVM did not affect embryo development.

Antioxidant supplementation overcomes the deleterious effects of maternal restraint stress-induced oxidative stress on mouse oocytes.

In this study, using a mouse model, we tested the hypothesis that restraint stress would impair the developmental potential of oocytes by causing oxidative stress and that antioxidant supplementation could overcome the adverse effect of stress-induced oxidative stress. Female mice were subjected to restraint stress for 24 h starting 24 h after equine chorionic gonadotropin injection. At the end of stress exposure, mice were either killed to recover oocytes for in vitro maturation (IVM) or injected with human chorionic gonadotropin and caged with male mice to observe in vivo development. The effect of antioxidants was tested in vitro by adding them to IVM medium or in vivo by maternal injection immediately before restraint stress exposure. Assays carried out to determine total oxidant and antioxidant status, oxidative stress index, and reactive oxygen species (ROS) and glutathione levels indicated that restraint stress increased oxidative stress in mouse serum, ovaries, and oocytes. Whereas the percentage of blastocysts and number of cells per blastocyst decreased significantly in oocytes from restraint-stressed mice, addition of antioxidants to IVM medium significantly improved their blastocyst development. Supplementation of cystine and cysteamine to IVM medium reduced ROS levels and aneuploidy while increasing glutathione synthesis and improving pre- and postimplantation development of oocytes from restraint-stressed mice. Furthermore, injection of the antioxidant epigallocatechin gallate into restraint-stressed mice significantly improved the blastocyst formation and postimplantation development of their oocytes. In conclusion, restraint stress at the oocyte prematuration stage impaired the developmental potential of oocytes by increasing oxidative stress and addition of antioxidants to IVM medium or maternal antioxidant injection overcame the detrimental effect of stress-induced oxidative stress. The data reported herein are helpful when making attempts to increase the chances of a successful outcome in human IVF, because restraint was applied at a stage similar to the FSH stimulation period in a human IVF program.

Repeated administration of PEP-1-Cu,Zn-superoxide dismutase and PEP-1-peroxiredoxin-2 to senescent mice induced by D-galactose improves the hippocampal functions.

Oxidative stress initiates age-related reduction in hippocampal neurogenesis and the use of antioxidants has been proposed as an effective strategy to prevent or attenuate the reduction of neurogenesis in the hippocampus. In the present study, we investigated the effects of Cu,Zn-superoxide dismutase (SOD1) and/or peroxiredoxin-2 (PRX2) on cell proliferation and neuroblast differentiation in the dentate gyrus in a model of D-galactose-induced aging model. For this study, we constructed an expression vector, PEP-1, fused PEP-1 with SOD1 or PRX2, and generated PEP-1-SOD1 and PEP-1-PRX2 fusion protein. The aging model was induced by subcutaneous injection of D-galactose (100 mg/kg) to 6-week-old male mice for 10 weeks. PEP-1, PEP-1-SOD1 and/or PEP-1-PRX2 fusion protein was intraperitoneally administered to these mice at 13-week-old once a day for 3 weeks and sacrificed at 30 min after the last administrations. The administration of PEP-1-SOD1 and/or PEP-1-PRX2 significantly improved D-galactose-induced deficits on the escape latency, swimming speeds, platform crossings, spatial preference for the target quadrant in Morris water maze test. In addition, the administration of PEP-1-SOD1 and/or PEP-1-PRX2 ameliorated D-galactose-induced reductions of cell proliferation and neuroblast differentiation in the dentate gyrus and significantly reduced D-galactose-induced lipid peroxidation in the hippocampus. These effects were more prominent in the PEP-1-SOD1-treated group with PEP-1-PRX2. These results suggest that a SOD1 and/or PRX2 supplement to aged mice could improve the memory deficits, cell proliferation and neuroblast differentiation in the dentate gyrus of D-galactose induced aged mice by reducing lipid peroxidation.

Effect of andrographolide on cysteamine-induced duodenal ulcer in rats.

The aim of this study was to evaluate the gastroprotective efficacy of andrographolide isolated from Andrographis paniculata in rats induced with duodenal ulcers. Duodenal ulcers were induced by cysteamine administration in rats pretreated with 3 mg kg⁻¹ BW day⁻¹ of andrographolide for 30 days. Ulcer score, myeloperoxidase activity, TBARS level, GSH/GSSG ratio and enzyme antioxidants were measured in the duodenal tissue. Brush border and basolateral membranes were isolated to assay sucrase, maltase, alkaline phosphatase and total ATPases. Ulcer score was significantly minimised in rats pretreated with andrographolide. Elevation in myeloperoxidase and TBARS levels were found to be minimised significantly due to andrographolide treatment. Membrane-bound enzyme activities and the thiol redox status of glutathione were significantly maintained in duodenal mucosa of rats that received andrographolide. This study reveals that the major component of A. paniculata, andrographolide, has potent antiulcer properties that are most likely caused by minimising inflammatory changes, counteracting free radical formation and maintaining the thiol redox status in the duodenum.

Cysteamine increases expression and activity of H+-K+-ATPase of gastric mucosal cells in weaning piglets.

AIM: To determine the in vivo and in vivo effects of cysteamine (CS) on expression and activity of H(+)-K(+)-ATPase of gastric mucosal cells in weaning piglets. METHODS: Eighteen litters of newborn Xinhuai piglets were employed in the in vivo experiment and allocated to control and treatment groups. From 12 d of age (D12), piglets in control group were fed basal diet, while the treatment group received basal diet supplemented with 120 mg/kg CS. Piglets were weaned on D35 in both groups. Six piglets from each group (n = 6) were slaughtered on D28 (one week before weaning), D35 (weaning), D36.5, D38, D42, and D45 (36 h, 72 h, one week and 10 d after weaning), respectively. Semi-quantitative RT-PCR was performed to determine the levels of H(+)-K(+)-ATPase mRNA in gastric mucosa. H(+)-K(+)-ATPase activity in gastric mucosa homogenate was also determined. Gastric mucosal epithelial cells from piglets through primary cultures were used to further elucidate the effect of CS on expression and activity of H(+)-K(+)-ATPase in vivo. Cells were treated for 20 h with 0.001, 0.01, and 0.1 mg/mL of CS (n = 4), respectively. The mRNA expression of H(+)-K(+)-ATPase and somatostatin (SS) as well as the H(+)-K(+)-ATPase activity were determined. RESULTS: in vivo, both mRNA expression and activity of H(+)-K(+)-ATPase in gastric mucosa of control group exhibited a trend to increase from D28 to D45, reaching a peak on D45, but did not show significant age differences. Furthermore, neither the mRNA expression nor the activity of H(+)-K(+)-ATPase was affected significantly by weaning. CS increased the mRNA expression of H(+)-K(+)-ATPase by 73%, 53%, 30% and 39% on D28 (P = 0.014), D35 (P = 0.017), D42 (P = 0.013) and D45 (P = 0.046), respectively. In accordance with the mRNA expression, H(+)-K(+)-ATPase activities were significantly higher in treatment group than in control group on D35 (P = 0.043) and D45 (P = 0.040). In vivo, CS exhibited a dose-dependent effect on mRNA expression and activity of H+-K+-ATPase. Both H(+)-K(+)-ATPase mRNA expression and activity in gastric mucosal epithelial cells were significantly elevated after 20 h of exposure to the moderate (H(+)-K(+)-ATPase expression: P=0.03; H(+)-K(+)-ATPase activity: P = 0.014) and high concentrations (H(+)-K(+)-ATPase expression: P=0.017; H(+)-K(+)-ATPase activity: P = 0.022) of CS. Significant increases in SS mRNA expression were observed to accompany the elevation of H(+)-K(+)-ATPase expression and activity induced by the moderate (P = 0.024) and high concentrations (P = 0.022) of CS. Low concentration of CS exerted no effects either on expression and activity of H(+)-K(+)-ATPase or on SS mRNA expression in cultured gastric mucosal epithelial cells. CONCLUSION: No significant changes are observed in mRNA expression and activity of H(+)-K(+)-ATPase in gastric mucosa of piglets around weaning from D28 to D45. CS increases expression and activity of gastric H(+)-K(+)-ATPase in vivo and in vivo. SS is involved in mediating the effect of CS on gastric H(+)-K(+)-ATPase expression and activity in weaning piglets.

Exogenous gamma-glutamyl cycle compounds supplemented to in vitro maturation medium influence in vitro fertilization, culture, and viability parameters of porcine oocytes and embryos.

High concentrations of intracellular glutathione (GSH) enhance in vitro production of porcine embryos. Objectives were: (1) to determine the effects of gamma-glutamyl cycle compound supplements to the IVM medium on IVF and IVC; and (2) to evaluate embryo viability. Porcine oocytes were matured in NCSU 23 medium supplemented with either l-cysteine (3.3 mM), l-cysteamine (150 P < 0.05microM), l-cysteine and l-cystemaine, l-glycine (1, 2.5, or 5 mM), l-glutamate (1, 2.5, or 5 mM), l-alpha-aminobutyrate (3.3mM), beta-mercaptoethanol (BME) (25 microM), l-cysteine and BME, or l-alpha-aminobutyrate and BME. Increases (P < 0.05) in GSH concentrations were observed using l-cysteine, 1.0 mM l-glutamate, l-alpha-aminobutyrate, and l-alpha-aminobutyrate with BME. Oocytes matured with l-alpha-aminobutyrate and BME had a lower (P < 0.05) occurrence of polyspermy during IVF compared to controls and a greater percentage (P < 0.05) of embryos reaching the blastocyst stage compared to other treatment groups. For Objective 2, oocytes were matured in NCSU 23 or NCSU 23 supplemented with l-alpha-aminobutyrate with BME. Embryo cell death was determined using an Annexin V-FITC assay. Supplementation had no effect on the time of cell death. Embryo mortality was increased (P < 0.05) from 24 to 42 h post-IVF, with the greatest occurrence around 36 h. In conclusion, supplementing l-alpha-aminobutyrate and BME into the IVM medium increased intracellular GSH concentrations, decreased the occurrence of polyspermy during IVF, and increased embryo development parameters during IVC, but did not affect cell death during embryo development. The onset of cell death occurred from 24 to 42 h post-IVF, with the greatest occurrence around 36 h post-IVF.

Cysteamine-a somatostatin-inhibiting agent-induced growth hormone secretion and growth acceleration in juvenile grass carp (Ctenopharyngodon idellus).

Effects of cysteamine hydrochloride (CSH)-a somatostatin-inhibiting agent on growth hormone (GH) secretion from pituitary fragments (PF) or hypothalamus plus pituitary fragments (HPF) under static incubation conditions, serum GH, 3,5,3(')-triiodothyronine (T(3)) and thyroxine (T(4)) levels, and growth in juvenile grass carp (Ctenopharyngodon idellus) were investigated. CSH (0.1, 1, and 10 mM) had no influences on GH release from PF after 1 and 6h incubation, but was effective in stimulating GH release from HPF in a dose-dependent manner after 1 and 6h incubation. Moreover, prolonged treatment of HPF with CSH decreased the magnitude of enhancement of GH levels in culture medium. CSH and neuropeptides [e.g., human GH-releasing hormone (hGHRH, 100 nM), luteinizing hormone-releasing hormone analog (LHRH-A, [D-Trp(6),Pro(9)]LHRH, 100 nM)], or salmon gonadotropin-releasing hormone analogue (sGnRH-A, [D-Ala(6),Pro(9)]LHRH, 100 nM), alone and in combination during static incubation stimulated GH release from HPF after 1h incubation; in addition, there was an additive, not a synergistic effect of CSH and neuropeptides on stimulation of GH release. Administration of CSH (2.5mg/g diet) in combination with LHRH-A (5 microg/g diet) in diet twice daily for 8 weeks resulted in higher serum GH, T(3), and T(4) levels, ratio of RNA/DNA in muscle, food conversion efficiency, and growth rate than CSH or LHRH-A alone. At trial termination, significant decreases in condition factors and body lipid levels were observed in fish fed with CSH and/or LHRH-A. No significant differences were recorded for viscero-somatic index, hepato-somatic index, and percent body moisture and protein in muscle. These findings, taken as a whole, strongly suggest that the action of CSH stimulating GH release in vitro appears to be mediated through hypothalamic pathways and dietary delivery of CSH directly or indirectly stimulates endogenous GH, T(3), and T(4) secretion, and subsequently leads to a increase in growth rate in grass carp.

Male pronuclear formation in denuded porcine oocytes after in vitro maturation in the presence of cysteamine.

The present study was conducted to examine effects of cysteamine in culture medium on progression of meiosis, glutathione (GSH) content, kinase activities (histone H1 kinase and mitogen-activated protein kinase), and male pronuclear formation after in vitro insemination of cumulus-denuded oocytes (DOs) in the pig. DOs, obtained by mechanically removing cells from cumulus-oocyte complexes (COCs) with a small-bore pipette, were cultured for 45 h in TCM199 supplemented with sodium pyruvate, gonadotropins, estradiol, and 10% porcine follicular fluid, with or without cysteamine (150 microM). Maturation rates of DOs cultured with and without cysteamine were not different (60-70%) but were significantly lower than those of COCs (90-100%) (p < 0.05). GSH content of matured DOs cultured with cysteamine was significantly higher than that of DOs cultured without cysteamine (p < 0.05). Values for both types of kinase activity in matured DOs cultured with and without cysteamine were not different (p > 0.05). After in vitro insemination, DOs cultured with cysteamine showed significantly higher rates of male pronuclear formation (80.3 +/- 3.0%) than DOs cultured without cysteamine (16.4 +/- 0.5%) (p < 0.05). These results indicate that the addition of cysteamine to culture medium increased oocyte GSH content and promoted male pronuclear formation after sperm penetration of porcine DOs but had no effects on their maturation rates or kinase activities.

Comparative studies of intracerebroventricularly administered cysteamine and pantethine in different behavioral tests and on brain catecholamines in rats.

In a passive avoidance test, intracerebroventricular administration (post-trial treatment) of the somatostatin-depleting compound cysteamine decreased the avoidance latency of the rats in a dose-related manner, while the effect of pantethine (which is metabolized to cysteamine) was less pronounced. In open-field studies, both compounds decreased the motor activity (ambulation, rearing) of the animals 15 min after the injection followed by a subsequent recuperation of the locomotor depression. Following pantethine, the ambulation increased during the later tests (60 min, 240 min, 24 hr). Cysteamine decreased the noradrenaline and increased the dopamine and dihydroxyphenyl acetic acid content in the hypothalamus, whereas the effects of pantethine were less expressed. Both compounds slightly decreased the striatal noradrenaline and increased the dihydroxyphenyl acetic acid levels at 15 and 60 min after administration. However, contrary to pantethine, 4 hr after treatment with cysteamine, there was a decrease in dihydroxyphenyl acetic acid concentration in this brain region. These findings suggest that both pantethine and cysteamine attenuate passive avoidance latency after intracerebroventricular treatment. The different efficiency of pantethine and its metabolite cysteamine might be connected to the low pantetheinase activity of the brain tissue; however, some direct effects of pantethine cannot be excluded. The different effects of the two compounds on the open-field activity are possibly associated with the diverse effects of the compounds on the striatal dopaminergic neurotransmission.

Effects of systemic and intracerebroventricular cysteamine on dexamethasone-induced suppression of corticosterone levels in the rat.

To investigate whether somatostatin systems plays a significant role in the regulation of the hypothalamic-pituitary-adrenal axis, the effects of cysteamine, a drug which reduces somatostatin levels, on the dexamethasone-induced suppression of plasma corticosterone levels were examined in the rat. Male Long Evans rats were handled daily for 1 week prior to receiving a standard dexamethasone suppression test. On the 1st day, rats received a 9.00 a.m. saline injection and blood samples were taken from the tail at 1.00 p.m. On the 2nd day, rats received dexamethasone or saline at 9.00 a.m. and a second blood sample was taken at 1.00 p.m. Experimental groups were pretreated with systemic injections of cysteamine, 5 min or 14 h, prior to receiving dexamethasone. Additional groups, previously implanted with guide cannulae, were given an infusion of cysteamine or saline into the lateral ventricle 14 h prior to dexamethasone. Circulating corticosterone levels were determined by radioimmunoassay. Rats were sacrificed immediately following each experiment and the hypothalamus dissected and assayed for levels of somatostatin immunoreactivity. The results of the first experiment showed that dexamethasone (10 micrograms/kg) alone reduced plasma corticosterone levels from control values (174 +/- 36 ng/ml) to undetectable levels (less than 25 ng/ml). Pretreatment with cysteamine 5 min prior to dexamethasone, while having no significant effect on basal corticosterone levels, completely blocked the dexamethasone-induced suppression of corticosterone levels. Similar observations were obtained with rats pretreated with cysteamine 14 h prior to dexamethasone. In contrast, intracerebroventricular cysteamine pretreatment did not block the dexamethasone-induced suppression of corticosterone levels. These results add further evidence in support of an involvement of somatostatin systems in the regulation of the hypothalamic-pituitary-adrenal axis.

[Bovicystan treatment of subclinical ketosis in cows]. / Lekuvane na subklinichnata ketoza pri kravi s bovitsistan.

Experiments with normal animals (10 sheep and 15 cows) revealed that the intravenous injection of bovicystan led to a considerable and dependable rise of the blood sugar for 2 to 36 hours the peak being at the 6th hour. The treatment of 95 freshly calved cows on 8 farms with signs of subclinical ketosis (ketonemia 22.4 +/- 1.9 mg%, ketonuria up to dilution of 1:2-1:16 and hypoglycemia 26.7 +/- 2.6 mg%) resulted in a 92.6 per cent total curative effect, consisting in the full inhibition of ketonuria, drop of the ketone bodies in the blood up to 16.5 +/- 1.2 mg%, on an average, and rise of the blood sugar up to 47.7 +/- 1.2 mg%, on an average. In 27.4 per cent of the treated cows ketonuria disappeared after the first injection, in 50.5 per cent - after the second one, and in 14.7 per cent only did ketonuria faded after the third injection of the preparation within a period of 24 hours. At the 48th hour following the last introduction of bovicystan there was an increase in the blood serum level of carotene and lactose, and a decrease in the level of inorganic phosphorus. One to three weeks after treatment with bovicystan in some 27.6 to 33.0 per cent of the cows on 2 of the farms signs of subclinical ketosis reappeared.