Biomedical subjects

Xiong Zhang

Publications and source records attributed to Xiong Zhang.

At least 19 recordsLinked to original sources

PubMed2026

RNAi in the Rhizarian Phytopathogen Plasmodiophora brassicae: The Causal Agent of Clubroot Disease in Cruciferous Crops.

Although RNA interference (RNAi) is widespread and functionally important across eukaryotes, RNAi pathways are diverse or even lost in some lineages. Rhizaria represents a major and distinct eukaryotic supergroup that includes Plasmodiophora brassicae (Pb), the causal agent of cruciferous clubroot disease, yet RNAi in this lineage remains poorly understood. Here, we characterized an unusual RNAi pathway in Pb. Small RNA sequencing across five representative Pb life stages revealed abundant siRNAs and miRNAs characterized by a predominant 21-nt length, phased genomic distribution, 2-nt 3' overhangs, and a strong 5'-cytidine bias. Three Pb miRNAs were further validated by northern blotting and stem-loop RT-qPCR. Genome analysis identified two canonical AGO homologs, PbAGO1 and PbAGO2, but no Dicer homologs, except for an RNase III-containing Drosha-like protein, PbDRL. Functional analyses showed that PbAGO1 and PbAGO2 mediate gene silencing, whereas PbDRL is required for sRNA biogenesis. Further, the cell wall component chitin was identified from Pb zoosporangia during the early infection and RNAi interfering with its biosynthesis in transgenic plants of Arabidopsis and Brassica napus blocked Pb early infection and conferred broad-spectrum resistance. Our study uncovers an unusual RNAi pathway in Rhizaria and provides a promising strategy to control cruciferous clubroot disease.

Plasmodiophora brassicae↗

PubMed2026

Comparative evaluation of oxidative stress biomarkers F2-isoprostanes and 8-OHdG in Parkinson's disease and Type 2 Diabetes Mellitus: a systematic review and meta-analysis of human studies.

BACKGROUND: Oxidative stress is central to type 2 diabetes mellitus (T2DM) and Parkinson's disease (PD). However, the utility of biomarkers for lipid peroxidation (F2-isoprostanes) and DNA damage (8-OHdG) in the comorbidity of PD and T2DM remains unclear. METHODS: We conducted a systematic review and meta-analysis of 54 unique studies of human subjects aged ≥ 50 years (n = 7,521: 3,522 with T2DM, 722 with PD, and 3,277 controls), measuring biomarkers in serum, plasma, or leukocytes. Mixed-effects models quantified standardized differences (Hedges' g) across subgroups. RESULTS: In T2DM, F2-isoprostanes (g = 1.60, 95% CI: 0.95-2.25) and 8-OHdG (g = 2.64, 95% CI: 2.13-3.14) were markedly elevated (p < 0.001). Stronger effects were observed in younger cohorts and serum/plasma samples, with complications like nephropathy exhibiting extreme oxidative stress (g = 5.24). In PD, 8-OHdG was moderately elevated (g = 0.78, 95% CI: 0.18-1.39; p = 0.011), particularly in randomized controlled trials and plasma samples, whereas F2-isoprostanes were not significantly elevated (g = 0.47, 95% CI: -0.43-1.38). High heterogeneity in T2DM (I2 > 90%) reflected methodological variability. CONCLUSION: Distinct profiles - both markers elevated in T2DM but only 8-OHdG in PD - underscore 8-OHdG's potential in PD-T2DM comorbidity. Future research should focus on standardized assays, multi-compartmental or multi-modal sampling, and longitudinal studies to clarify mechanisms and therapeutic targets.

Humans↗

PubMed2025

Inactivation of β-1,3-glucan synthase-like 5 confers broad-spectrum resistance to Plasmodiophora brassicae pathotypes in cruciferous plants.

Clubroot disease, caused by the obligate intracellular rhizarian protist Plasmodiophora brassicae, is devastating to cruciferous crops worldwide. Widespread field P. brassicae pathotypes frequently overcome the pathotype-specific resistance of modern varieties, posing a challenge for durable control of this disease. Here a genome-wide association study of 3 years of data comprising field clubroot phenotyping of 244 genome-resequenced Brassica napus accessions identified a strong association of β-1,3-glucan synthase-like 5 (GSL5) with clubroot susceptibility. GSL5 was evolutionarily conserved, and inactivation of GSL5 by genome editing in Arabidopsis, B. napus, Brassica rapa and Brassica oleracea conferred broad-spectrum, high-level resistance to P. brassicae pathotypes without yield penalties in B. napus. GSL5 inactivation derepressed the jasmonic acid-mediated immunity during P. brassicae secondary infection, and this immune repression was possibly reinforced through stabilization of GSL5 by a P. brassicae effector, facilitating clubroot susceptibility. Our study provides durable resistance resources for cruciferous clubroot disease control and insights into plant resistance against intracellular eukaryotic phytopathogens.

Disease Resistance↗

PubMed2006

Allodynia and hyperalgesia suppression by a novel analgesic in experimental neuropathic pain.

SCP-1, n-[alpha-(benzisothiazol-3(2ho-ona,1-dioxide-2yl)-acetyl]-p-aminophenol (100 nmol), when intrathecally injected, suppressed tactile allodynia and thermal hyperalgesia in a rat neuropathic pain model. The tactile allodynia suppression lasted for at least 4h and SCP-M1 (100 nmol), the main metabolite of SCP-1, displayed similar suppression as SCP-1, but shorter latency, indicating SCP-M1 may be the bioactive component of SCP-1. Acetaminophen was less potent than SCP-1 and SCP-M1. To study mechanisms underlying SCP-1 action, we recorded voltage-gated Ca(2+) channel currents in acutely isolated dorsal root ganglion neurons using the whole-cell patch-clamp technique. SCP-1 and SCP-M1 inhibited non-L-type calcium channel currents up to 23.0+/-2.3% and 23.1+/-3.5%, respectively, at a depolarized pulse to -10 mV from a holding potential of -80 mV. Acetaminophen only induced 6.8+/-1.0% inhibition. The results suggest SCP-1 possesses anti-nociceptive activity in the rat model involving calcium channel blocking properties.

Acetaminophen↗

PubMed2006

The neuroprotection conferred by activating the mitochondrial ATP-sensitive K+ channel is mediated by inhibiting the mitochondrial permeability transition pore.

In order to further explore the mechanisms by which activation of mitochondrial ATP-sensitive potassium channels (mitoKATP) confers neuroprotection, we investigated the role of the mitochondrial permeability transition pore (MPTP) in in vivo and in vitro models. Adult male Sprague-Dawley rats were exposed to 90 min of middle cerebral artery occlusion (MCAO) followed by reperfusion for 22 h, when neurological scores and infarct volumes were evaluated. Activating mitoKATP by infusion of 2 mmol/L diazoxide into the ventricles 20 min before MCAO or inhibiting the MPTP by infusion of 1 micromol/L cyclosporin A 15 min before reperfusion significantly increased functional score and reduced infarction volume. Subsequent intracerebroventricular infusion of 2 mmol/L atractyloside, the MPTP opener, 10 min before reperfusion significantly attenuated the neuroprotective effects of diazoxide and cyclosporin A. The swelling of mitochondria isolated from brain was evaluated by spectrophotometry and served as a measure of MPTP opening. In isolated mitochondria, 100 micromol/L atractyloside attenuated the decrease of mitochondrial swelling induced by 30 micromol/L diazoxide or cyclosporin A (0.5 or 1 micromol/L). Furthermore, 100 micromol/L diazoxide or 1 micromol/L cyclosporin A both attenuated the fluorescence intensity in isolated mitochondria loaded with rhod-2 acetoxymethylester, and 100 micromol/L atractyloside abolished the effects of diazoxide and cyclosporin A. These results suggest that activation of mitoKATP protects the brain against injury, and this is probably mediated by attenuating mitochondrial Ca2+ overload and thus inhibiting MPTP opening during brain ischemia and reperfusion.

Animals↗

PubMed2006

[Effect of panax notoginseng saponins injection on brain edema in intracerebral hemorrhage rats].

OBJECTIVE: To study the effect of panax notoginseng saponins (PNS) in treating hemorrhagic apoplexy at super-early stage in rats. METHODS: Rat model of hypertension with cerebral hemorrhage was induced by collagenase method. Sixty rats were randomly divided into 5 groups: the sham operated group, model group, PNS high, middle, and low dose group, 12 in each; 4 h after modeling, PNS or normal saline was intraperitoneally injected into the rats every 12 h, the total is 5 times. Contents of water, sodium and potassium ion in brain, and the diameter of hematoma in rats of different groups were measured 24 h and 72 h after modeling. RESULTS: Compared with the model rats, nerve defect symptoms aggravated, the contents of water and sodium ion in ipsilateral cortex and basal ganglia were significantly higher, the content of potassium ion was lower and the hematoma diameter was obviously less in the PNS-treated rats (all P < 0.05). CONCLUSION: PNS may worsen the brain edema and increase the nerve defect score when it was applied at the early stage of cerebral hemorrhage, but could promote the absorption of hematoma, indicating PNS should be used cautiously in treating patients with large amount of cerebral hemorrhage at super-early stage.

Animals↗

PubMed2005

Heterogeneous expression and regulation of hippocampal prostaglandin E2 receptors.

Although prostaglandin E2 (PGE2) has been shown to be critical to hippocampal synaptic signaling and neuronal survival, it is still not clear which subtypes of PGE2 receptors (EPs) are expressed and how these EPs are regulated in the hippocampus. To address these questions, the expression of the EPs was profiled in the hippocampus. Messenger RNAs and proteins of the four receptors, EP 1-4, were detected both in the hippocampus and in the neocortex. EP 2 and EP 3 appeared in greater abundance, whereas EP 1 and EP 4 were barely detectable. EP 1, EP 2 and EP 4 were mainly colocalized with synaptophysin, suggesting the presence of EP 1, EP 2, and EP 4 in presynaptic terminals. It appeared that interleukin-1 beta increased the expression of EP 2 and EP 4 mRNAs. A blockade of synaptic transmission with either tetrodotoxin or MK-801 plus 6,7-dinitroquinoxaline-2,3-dione (DNQX) for 6 hr increased EP 3 and EP 4 mRNA, whereas high K(+) (90 mM) or 4-aminopyridine enhanced EP 2 and EP 4. The EP 1 level did not change significantly under these conditions. The expressions of EP 2, EP 4, and EP 3 were further elevated or reduced in neurons treated with high K(+) for 24 hr. However, mRNA of EP 3 was down-regulated in neurons treated with tetrodotoxin or MK-801 plus DNQX for 24 hr. In addition, both EP 2 and EP 4 mRNAs were up-regulated within 4 hr after high-frequency stimulation associated with long-term potentiation induction in hippocampal slices. Our results indicate that the four EPs are heterogeneously expressed in the hippocampus, and their expression is differentially regulated by neuronal activities, suggesting that EPs may actively participate in hippocampal synaptic transmission and plasticity.

Animals↗

PubMed2005

Neuroprotection by iron chelator against proteasome inhibitor-induced nigral degeneration.

The cause of the neurodegenerative process in Parkinson's disease (PD) remains unclear, but evidence suggests that failure of the ubiquitin-proteasome system may play a major role in the pathogenesis of the disease. Iron is believed to be a key contributor to PD pathology by inducing aggregation of alpha-synuclein and by generating oxidative stress. Our present studies have shown that micro-injection of the proteasome inhibitor lactacystin into the substantia nigra (SN) of C57BL/6 mice causes significant loss of dopaminergic cells and induces intracellular inclusion body formation. We have also found that co-injection of the iron chelator desferrioxamine not only attenuates the lactacystin-induced dopamine neuron loss, but also reduces the presence of ubiquitin-positive intracellular inclusions in the SN, whereas use of iron-deficient diet has no such protective effects. These results may support that iron plays a key role in proteasome inhibitor-induced nigral pathology and that reducing iron reactivity may prevent dopaminergic neuron degeneration and reduce abnormal protein aggregation.

Acetylcysteine↗

PubMed2005

Genetic analysis of parkin co-regulated gene (PACRG) in patients with early-onset parkinsonism.

Parkin co-regulated gene (PACRG) is a recently identified gene which is transcriptionally co-regulated with parkin gene (PRKN) by a shared bidirectional promoter. To determine whether early-onset parkinsonism (EOP) is associated with PACRG mutation, we screened 112 patients with EOP and found three nucleotide variants: (1) T>C transition in intron 2 (nt 87004; NT_007422), (2) C>T transition (L214L) in exon 6 (nt 585706; NT_007422), and (3) T>A substitution in intron 5 (nt 585630; NT_007422), located 18 bp upstream from exon 6. Since none of these variations appear to be pathogenically relevant, our results suggest that mutation of PACRG plays little or no role in the development of EOP.

Adult↗

PubMed2005

[Expression of keratinocyte basement membrane related genes during the process of re-epithelialization of burn wound in scalded rats].

OBJECTIVE: To study the expression of keratinocyte (KC) basement membrane (BM) related genes during the process of re-epithelialization of burn wound in scalded rats with cDNA microarray technique. METHODS: Twenty-four SD rats were inflicted with deep partial thickness scald with an area of 45 cm(2) on the back, and they were randomly divided into A [3 postscald day (PSD)], B (10 PSD), C (14 PSD) and D (re-epithelialization complete day) groups, with 6 rats in each group. Tissue samples were harvested from 1 cm of wound margin on 3, 10 and 14 PSD. On the re-epithelialization complete day, tissue samples were harvested from the center of the wound in D group and digested with enzyme into KC suspensions. Skin samples from the back of 6 uninjured rats were taken as normal control. The differential expression of KC BM related genes during different stages of re-epithelialization was assayed with cDNA microarray. RESULTS: The expression of laminin (LN) gamma 1 (2.068) and integrin beta8 (2.200) was up-regulated on 3 PSD compared with that in control. The expression of integrin beta1 and LN receptor 1 was up-regulated on 10 and 14 PSD, (2.472 and 2.658), while that of integrin beta2 and beta1 (0.419 and 0.462) down-regulated on 10 and 14 PSD, and the expression of type IV collagen alpha1 and alpha3 was up-regulated during re-epithelialization. CONCLUSION: The expression of integrin beta1, LN gamma 1, LN receptor 1, type IV collagen alpha1 and alpha3 genes were up-regulated during re-epithelialization, which might be beneficial to the construction of BM in new skin and the formation of stable conjunction between KC and BM.

Animals↗

PubMed2005

[Analysis of 994(G--> T) mutation in the plasma platelet-activating factor acetylhydrolase gene in the patients with cerebral infarction].

OBJECTIVE: To investigate the relationship between plasma platelet-activating factor acetylhydrolase (PAF-AH) gene 994(G--> T) mutation in exon 9 and the patients with cerebral infarction in Chinese Hans. METHODS: The authors conducted a case-control study including 108 patients in three groups (atherosclerotic cerebral infarction group, lacunar infarction group and cerebral embolism group) and 215 normal subjects as controls. Genomic DNA was analyzed for the mutant allele by a specific polymerase chain reaction. RESULTS: The frequency of the mutant genotype in the 102 patients with cerebral infarction was 35.19%(32.41% heterozygotes and 2.78% homozygotes), and was 38.10%(34.92% heterozygotes and 3.18% homozygotes) in the atherosclerotic cerebral infarction group, being all significantly higher than the control group's 20.46% (18.60% heterozygotes and 1.86% homozygotes)(P< 0.01); however, the frequencies of the mutant genotype in the lacunar infarction group and cerebral embolism group were 32.35% (29.41% heterozygotes and 2.94% homozygotes) and 27.27% (27.27% heterozygotes and 0 homozygotes) respectively, being not statistically different from those of the controls (P> 0.05). CONCLUSION: These findings show that the 994(G--> T) mutation of plasma PAF-AH gene may be an independent risk for atherosclerotic cerebral infarction, but not for lacunar infarction.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

PubMed2005

[Association of TNFA-308 gene polymorphisms with susceptibility to chronic periodontitis in Chinese patients].

PURPOSE: The purpose of this study was to investigate the relationship between TNFalpha-308 gene polymorphisms and susceptibility to chronic periodontitis in Chinese patients. METHODS: DNA samples with buccal swabs were collected from 63 severe CP patients, 103 initial to moderate CP patients, and 80 healthy controls in Chinese Han nationality. The TNFA-308 gene polymorphisms were analyzed with PCR-RFLP. The data were analyzed by X(2) test using SPSS10.0. RESULTS: There were no significant genotype distribution differences of TNFA-308 between either two of the three subject groups. CONCLUSION: Further study was needed since we did not find the relationship between TNFA-308 gene polymorphism and periodontitis in this present study.

Asian People↗

PubMed2005

[The influence of topical application of insulin on the formation of basement membrane in scalded rats].

OBJECTIVE: To investigate the influence of topical application of insulin on the formation of basement membrane (BM) in rats with deep partial thickness scald. METHODS: Ninety-six SD rats were inflicted with deep partial thickness scald on the back and were randomized into A group (n = 48, with subcutaneous injection of 2 ml of isotonic saline on the 1 post scald day (PSD)) and B group (n = 48, with subcutaneous injection of 0.1 U of insulin and 2 ml of isotonic saline on the 1 PSD). The rats received the treatment every other day until wound re-epithelization completed. Then the rats were sacrificed on 2, 3, 4, 5, 6, 10, 14 PSD, and on the day when the wound re-epithelialized completely. The skin samples of 1 cm in width were harvested at the edge of the wound for reticular fiber staining and for morphological observation of the wound BM with transmission electron microscope. The expression of laminin-5 mRNA and laminin in keratinocyte was determined by RT-PCR and Western blotting, respectively. RESULTS: Integrated and continuous structure of the basement membrane was observed in B group. Laminin-5 mRNA expression was much higher in B group than that in A group on 10 and 14 PSD (P < 0.05 or P < 0.01). Laminin-5 mRNA expression was decreased in both groups when epithelialization completed. But the Laminin-5 protein expression on 14 PSD and the day of epithelization (56 +/- 8, 101 +/- 13) was obviously higher in B group than that in A group (39 +/- 5, 73 +/- 16), (P < 0.05). CONCLUSION: Subcutaneous injection of 0.1 U insulin beneath the scald wound is beneficial to the acceleration of the wound re-epithelialization process, and to the improvement of the wound healing quality.

Animals↗

PubMed2004

[Mechanisms of pethidine-induced vasodilatation].

OBJECTIVE: To investigate the vasodilating effects of pethidine, particularly in association with intracellular calcium. METHODS: Aorta rings of Sprague-Dawley rats, with or without endothelium, were prepared in organ bath to measure the vascular tone. Pre-contractions by KCl (80 mmol/L) and phenylephrine (PhE) (10(-6)mol/L) were induced. RESULTS: Pethidine did not alter the resting tension of aorta rings, but produced dose-dependent relaxation in KCl and PhE pre-treated aorta rings with or without endothelium. Pethidine did not change the caffeine-stimulated contraction, and still had similar inhibition in KCl pre-contracted aorta rings after pretreatment with ruthenium red. Pethidine decreased the contractile responses induced by PhE in Ca(2+)-free solution or by adding calcium into Ca(2+)-free solution. CONCLUSION: Pethidine could produce an endothelium-independent vasodilatation in KCl and PhE pre-contracted aorta rings, which is related to inhibition of Ca(2+)entry and IP3-sensitive Ca(2+) release in vascular smooth muscle.

Animals↗

PubMed2004

[The content of decorin and its mRNA expression in normal human skin and hyperplastic scars].

OBJECTIVE: To investigate the content of decorin and its mRNA expression in normal human skin and hyperplastic scars at different stages, so as to explore the relationship between the change of decorin and its synthesis. METHODS: Scar tissue samples from 22 patients undergoing scar excision and 10 specimens of normal skin or prepuce were obtained. The content and distribution of decorin in the tissue samples were determined with immunohistochemistry and Western blot, and the expression of decorin mRNA was detected by in situ hybridization. RESULTS: The content of decorin was rich in the normal skin dermis with lower expression of the mRNA. In contrast, the decorin content was scarce in hyperplastic scars (HS) within 6 months, but increased gradually beginning from 7 to 12 months, and increased continuously for 13 to 36 months. There was no difference between the decorin content in normal skin and that in HS after 36 months (P > 0.05). Furthermore, the mRNA expression level in HS tissue was lower than that in normal skin within 6 months, but increased from 7 to 12 months. The mRNA expression continuously increased during 13 to 36 months and then returned to the level similar to that in normal skin thereafter. CONCLUSION: The decrease of decorin in hyperplastic scar was resulted primarily from reduced synthesis. The increase in decorin level coincided with the time of scar tissue stabilization, which implied that the delayed appearance was correlated with the formation of HS.

Blotting, Western↗

PubMed2004

[Effects of topical application of insulin on the wound healing in scalded rats].

OBJECTIVE: To investigate the effects of topical application of small dose of insulin on the wound healing of the scalded rats, so as to explore its mechanism. METHODS: The rats employed in the study were subjected to deep partial thickness burn and were divided into group A (with subcutaneous injection of isotonic saline into the rat wounds as control), B and C (with subcutaneous injection of 0.1 U and 1 U insulin in the rat wounds respectively) and D (with subcutaneous injection of 0.1 U insulin in the rat abdomen as control). The wound healing time and wound healing rate were assessed every other day after 3 postburn days (PBDs). The histological changes of the wounds after injection were examined, the changes in the cell cycle of epidermal cells in the wound were analyzed by flow-cytometry, and blood glucose concentration of each group was determined. RESULTS: The wound healing time in group B (18.36 +/- 4.12 d) was significantly shorter than that in other groups (A: 24.57 +/- 5.19 d, C: 21.46 +/- 2.97 d, D: 24.50 +/- 1.05 d, P < 0.01). The wound healing rate of the rats in group B in 5, 9, 11, 13, 15, 17 and 19 PBD was obviously higher than that in group A, and was markedly higher than that in group C on 17 PBD (P < 0.05 - 0.01). The epithelial layer was thinner with less epidermal nails but much more fibroblasts in epidermal layer in group A, while the epithelial layer was thicker with abundant epidermal nails in group B and C with many fibroblasts in the dermis. The amount of cells in S phase at 4 PBD in group B was dramatically higher than that in group A, and cells in G2M phase at 4 - 5 PBD in group B was also higher than that in group A and C (P < 0.05 - 0.01). The blood level of glucose in group A and B fluctuated between 3.42 to 4.62 mmol/L at 24 PBH, while that in group C and D decreased obviously 1 hour after injection (P < 0.01), but gradually returned to normal 4 hours after injection. CONCLUSION: Local injection of small dose of insulin may accelerate burn wound healing due to its role in promoting the proliferation and division of the repairing cells.

Administration, Topical↗

PubMed2004

[Effect of puerarin on L-type calcium channel in isolated rat ventricular myocytes].

OBJECTIVE: To observe the effect of Puerarin on L-type calcium channel in isolated rat ventricular myocytes. METHOD: The cardiac ventricular myocytes were isolated enzymatically by Langendorff perfusion techniques at constant flow rate. Whole-cell recording of patch-clamp techniques was used to observe the current of L-type calcium channel. RESULT: Puerarin 2.4 mmol x L(-1) could inhibit the current of L-type calcium channel of rat ventricular myocytes and this inhibition was time-dependent. Purerarin elevated the current-voltage (I-V) curve of calcium current. CONCLUSION: Puerarin can inhibit L-type calcium current of rat ventricular myocytes. Which implies that puerarin takes part in anti-myocardial ischemia and anti-arrhythmics partly due to the inhibition of L-type calcium channel.

Animals↗

PubMed2003

Interleukin-2 increases activity of sarcoplasmic reticulum Ca2+-ATPase, but decreases its sensitivity to calcium in rat cardiomyocytes.

To further explore the role of interleukin-2 (IL-2) in cardiac function, we investigated its effects on the intracellular calcium transient and the activity of sarcoplasmic reticulum (SR) Ca2+-ATPase in rat cardiomyocytes. IL-2 (200 U/ml) decreased the amplitude of electrically stimulated and caffeine-induced intracellular Ca2+ transients in ventricular myocytes, but increased the end-diastolic calcium level. IL-2 did not affect the sarcolemmal L-type Ca2+ channel activity. The activity of SR Ca2+-ATPase from IL-2-treated hearts increased in a dose-dependent manner, but the sarcolemmal Ca2+-ATPase activity did not change. After incubation of SR with ATP, the activity of SR Ca2+-ATPase from IL-2-treated hearts increased much more than that in the control group. The responsiveness of SR Ca2+-ATPase from IL-2-perfused hearts to the free calcium concentration was inhibited. The Ca2+ uptake and Ca2+ content were reduced in the SR vesicles prepared from IL-2-treated rat heart. Pretreatment with the kappa-opioid receptor antagonist nor-binaltorphimine (10 nM) attenuated the effect of IL-2 on the SR Ca2+-ATPase activity, SR Ca2+ uptake, and Ca2+ content. The activity of Ca2+-ATPase in SR isolated from untreated hearts did not change when IL-2 and SR were coincubated. Thus, we conclude that the decreased calcium transient induced by IL-2 results from reduced SR calcium release, which is due to decreased SR Ca2+ uptake mediated by cardiac kappa-opioid receptors, but not from reduced activity of the sarcolemmal L-type calcium channel.

Adenosine Triphosphate↗