CPP Treatment Research Articles

Serum metabolomic analysis reveals key metabolites in drug treatment of central precocious puberty in female children.

Precocious puberty (PP) is a common condition among children. According to the pathogenesis and clinical manifestations, PP can be divided into central precocious puberty (CPP, gonadotropin dependent), peripheral precocious puberty (PPP, gonadotropin independent), and incomplete precocious puberty (IPP). Identification of the variations in key metabolites involved in CPP and their underlying biological mechanisms has increased the understanding of the pathological processes of this condition. However, little is known about the role of metabolite variations in the drug treatment of CPP. Moreover, it remains unclear whether the understanding of the crucial metabolites and pathways can help predict disease progression after pharmacological therapy of CPP. In this study, systematic metabolomic analysis was used to examine three groups, namely, healthy control (group N, 30 healthy female children), CPP (group S, 31 female children with CPP), and treatment (group R, 29 female children) groups. A total of 14 pathways (the top two pathways were aminoacyl-tRNA biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis) were significantly enriched in children with CPP. In addition, two short peptides (His-Arg-Lys-Glu and Lys-Met-His) were found to play a significant role in CPP. Various metabolites associated with different pathways including amino acids, PE [19:1(9Z)0:0], tumonoic acid I, palmitic amide, and linoleic acid-biotin were investigated in the serum of children in all groups. A total of 45 metabolites were found to interact with a chemical drug [a gonadotropin-releasing hormone (GnRH) analog] and a traditional Chinese medicinal formula (DBYW). This study helps to understand metabolic variations in CPP after drug therapy, and further investigation may help develop individualized treatment approaches for CPP in clinical practice.

The Immunomodulatory Effects of Phellodendri Cortex Polysaccharides on Cyclophosphamide-Induced Immunosuppression in Mice.

Cyclophosphamide is a commonly used anticancer drug, and immunosuppression is one of the most common side effects. How to recover the immunological function is important for cyclophosphamide-treated patients. In the present study, Phellodendri Cortex polysaccharides (CPP) could enhance the proliferation of mouse spleen lymphocytes in vitro. The immunoregulatory function of CPP was then investigated in cyclophosphamide-induced immunosuppressed mice. In CPP-treated groups, mice were orally treated with CPP at doses of 1, 0.5, and 0.25 g/kg bodyweight from 1 to 11 d, respectively. The cyclophosphamide was administrated in CPP and cyclophosphamide groups from 12 to 14 d. In the cyclophosphamide and normal control groups, the mice received equal volume of saline from 1 to 14 d. The results showed that CPP (1 g/kg) could significantly increase the bodyweight of mice, even during cyclophosphamide treatment. The organ coefficients of the spleen and thymus were recovered by CPP treatment. CPP upregulated the contents of cytokines (IL-2, IL-6, IFN-γ, and TNF-α) in serum, which were downregulated by cyclophosphamide. The mRNA levels of these cytokines were also elevated by CPP treatment in the spleen. Cyclophosphamide upregulated the expressions of NF-κB p65, TLR4, and MyD88, suggesting that the NF-κB signaling pathway was activated by cyclophosphamide. After CPP treatment, it was recovered to normal level. These results indicated that CPP alleviated the cyclophosphamide-induced immunosuppression.

Pathogenic and Low-Frequency Variants in Children With Central Precocious Puberty.

BackgroundCentral precocious puberty (CPP) due to premature activation of GnRH secretion results in early epiphyseal fusion and to a significant compromise in the achieved final adult height. Currently, few genetic determinants of children with CPP have been described. In this translational study, rare sequence variants in MKRN3, DLK1, KISS1, and KISS1R genes were investigated in patients with CPP.MethodsFifty-four index girls and two index boys with CPP were first tested by Sanger sequencing for the MKRN3 gene. All children found negative (n = 44) for the MKRN3 gene were further investigated by whole exome sequencing (WES). In the latter analysis, the status of variants in genes known to be related with pubertal timing was compared with an in-house Cypriot control cohort (n = 43). The identified rare variants were initially examined by in silico computational algorithms and confirmed by Sanger sequencing. Additionally, a genetic network for the MKRN3 gene, mimicking a holistic regulatory depiction of the crosstalk between MKRN3 and other genes was designed.ResultsThree previously described pathogenic MKRN3 variants located in the coding region of the gene were identified in 12 index girls with CPP. The most prevalent pathogenic MKRN3 variant p.Gly312Asp was exclusively found among the Cypriot CPP cohort, indicating a founder effect phenomenon. Seven other CPP girls harbored rare likely pathogenic upstream variants in the MKRN3. Among the 44 CPP patients submitted to WES, nine rare DLK1 variants were identified in 11 girls, two rare KISS1 variants in six girls, and two rare MAGEL2 variants in five girls. Interestingly, the frequent variant rs10407968 (p.Gly8Ter) of the KISS1R gene appeared to be less frequent in the cohort of patients with CPP.ConclusionThe results of the present study confirm the importance of the MKRN3-imprinted gene in genetics of CPP and its key role in pubertal timing. Overall, the results of the present study have emphasized the importance of an approach that aligns genetics and clinical aspects, which is necessary for the management and treatment of CPP.

Physicochemical characterization and antioxidant effects of green microalga Chlorella pyrenoidosa polysaccharide by regulation of microRNAs and gut microbiota in Caenorhabditis elegans

A novel polysaccharide from Chlorella pyrenoidosa (CPP) was separated and purified with the average molecular weight 15.8 kDa. It was composed of seven monosaccharides including mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. FT-IR and NMR spectra analysis further revealed that CPP was an acidic polysaccharide consisting of β-L-Arap-(1→, →2)-α-L-Rhap-(1→, β-D-GlcpA-(1→, →4)-α-D-GalpA-(1→, →6)-β-D-Glcp-(1→, →3)-β-D-Manp-(1→, and →3, 6)-β-D-Galp-(1→. The CPP treatment could effectively prolong lifespan of Caenorhabditis elegans under the oxidative stress conditions and inhibit the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) as well as enhancing the level of superoxide dismutase (SOD). It could up-regulate the expressions of Daf-16 and Skn-1 genes via declining miR-48-3p, miR-48-5p, and miR-51-5p translocation. Moreover, 16S rRNA sequencing revealed that the CPP-enriched Faecalibacterium, Haemophilus, Vibrio, and Shewanella were strongly correlated with SOD, MDA, apoptosis, and ROS. These results indicated that CPP may be considered as a desired ingredient on regulating the aging and oxidative diseases.

Superior hypogastric plexus block as an effective treatment method for endometriosis-related chronic pelvic pain: an open-label pilot clinical trial

We aimed to investigate the effect of superior hypogastric plexus (SHP) block on pain relief and quality of life of patients with refractory endometriosis. Sixteen patients with refractory endometriosis underwent SHP block. The outcome measures included visual analogue scale (VAS) for chronic pelvic pain, VAS for dysmenorrhoea, and VAS for dyspareunia. The short-form endometriosis health profile (EHP-5) was used to measure quality of life. All the outcome measures were evaluated at weeks 0, 1, 4, 12 and 24. The mean baseline VAS scores significantly improved after the SHP block (p < .001 for all). The mean overall EHP-5 score also significantly improved from 54.3 ± 18.2 to 24.6 ± 13.3 (p < .001). The positive effects of SHP were not diminished over time. No serious adverse effect was noticed in any of the patients. Preliminary results suggest that SHP block could be used as an effective method in pain control and improvement of quality of life in refractory endometriosis. IMPACT STATEMENT What is already known on this subject? Safety and efficacy of SHP block in the treatment of CPP has been revealed in earlier investigations. However, the efficacy of SHP block for pain management in patients with refractory endometriosis has not been investigated in earlier investigations. What do the results of this study add? SHP block is an effective method for pain control and improvement of quality of life in patients with refractory endometriosis. The positive effects of this treatment did not diminish over 24-weeks follow-up of the study. No serious adverse effect was noticed in any of the patients. What are the implications of these findings for clinical practice and/or further research? Preliminary results suggest that SHP block could be used safely and effectively for controlling pain and improvement of quality of life in patients with refractory endometriosis.

Cyclocarya paliurus (Batal.) Iljinskaja polysaccharides alleviate type 2 diabetes mellitus in rats by resisting inflammatory response and oxidative stress

Abstract This study aimed to investigate the effects of Cyclocarya paliurus (Batal.) Iljinskaja polysaccharides (CPP) on the glucose-lipid metabolism in T2DM rats. T2DM model was established in 40 Wistar rats which were then randomly divided into model, CPP-1, CPP-2 and CPP-3 groups. Ten normal rats were selected as the control group. The CPP-1, CPP-2 and CPP-3 group were intragastrically administrated with 100, 200 and 400 mg/kg CPP for 4 weeks, respectively. Results showed that, during the treatment, compared with model group, in CPP treatment groups the T2DM symptoms were lightened, and the body weight was improved. After treatment, compared with model group, in CPP-3 group the blood fasting plasma glucose, fasting insulin and glycosylated hemoglobin levels were reduced (P < 0.05), the blood total cholesterol, triglyceride and low-density lipoprotein cholesterol levels were decreased (P < 0.05), the serum C-reactive protein, tumor necrosis factor α and interleukin 6 levels were decreased (P < 0.05), the serum malondialdehyde level was reduced (P < 0.05), and the serum superoxide dismutase and glutathione peroxidase levels were increased (P < 0.05). In conclusion, CPP can alleviate the T2DM in rats, which may be related to its resisting inflammatory response and oxidative stress in body.

NMDA Receptors in Visual and Olfactory Sensory Integration in Male Long Evans Rats: A Role for the Orbitofrontal Cortex

Sensory integration (SI) is a cognitive process whereby the brain uses unimodal or multimodal sensory features to create a comprehensive representation of the environment. Integration of sensory input is necessary to achieve a coherent perception of the environment, and to subsequently plan and coordinate action. The neural mechanisms mediating SI are poorly understood; however, recent studies suggest that the regulation of SI involves N-methyl-d-aspartate receptors (NMDARs) in orbitofrontal cortex (OFC). Thus, we tested this hypothesis directly in two experiments using object oddity tests that require SI for visual and olfactory stimuli. First, we blocked NMDARs with acute CPP treatment (i.p., 10 mg/kg) and tested rats in unimodal visual and olfactory SI tests, and respective control unimodal oddity tests that do not require SI. Second, we used intra-OFC infusions of AP5 (30 mM) to examine the role of NMDARs in the OFC in the oddity tests requiring SI. Systemic blockade of NMDARs impaired performance on the visual tests regardless of whether SI was required for determining oddity. In the olfactory tests, systemic treatment with CPP impaired the test requiring SI while sparing olfactory oddity, demonstrating a selective impairment in the olfactory SI. Intra-OFC blockade of NMDARs impaired olfactory SI, without effect on visual SI, demonstrating that intra-OFC NMDARs are essential for olfactory, but not visual SI. The present results are discussed in the context of the function of the OFC and its associated circuitry.

Lower abdominal pain as a problem in child gynecology

Lower abdominal pain in a girl is a common problem in gynecology of the developmental age (10-20%). It corresponds to the criteria of the concept of “chronic pelvic pain” (CPP), which is defined in accordance with the American College of Obstetricians and Gynecologists (ACOG) as chronic, non-cyclical pain in the area of the lower abdomen, unrelated to the menstrual cycle, lasting at least three months, or cyclic pain lasting for six months. The overriding aim of treatment of CPP in girls and young women is to alleviate existing pain, prevent recurrence of chronic symptoms, ensure future reproductive functions, and restore proper functioning and improve quality of life.

Cationic cell-penetrating peptide is bactericidal against Neisseria gonorrhoeae.

Cell-penetrating peptides (CPPs) have been evaluated for intracellular delivery of molecules and several CPPs have bactericidal activity. Our objectives were to determine the effect of a 12 amino acid CPPs on survival and on the invasive and inflammatory potential of Neisseria gonorrhoeae. Survival of MDR and human challenge strains of N. gonorrhoeae grown in cell culture medium with 10% FBS was determined after treatment with the CPP and human antimicrobial peptide LL-37 for 4 h. Confocal microscopy was used to examine penetration of FITC-labelled CPP into bacterial cells. The ability of the CPP to prevent invasion of human ME-180 cervical epithelial cells and to reduce the induction of TNF-α in human THP-1 monocytic cells in response to gonococcal infection was assessed. Cytotoxicity of the CPP towards the THP-1 cells was determined. The CPP was bactericidal, with 95%-100% killing of all gonococcal strains at 100 μM. Confocal microscopy of gonococci incubated with FITC-labelled CPP revealed the penetration of the peptide. CPP treatment of N. gonorrhoeae inhibited gonococcal invasion of ME-180 cells and reduced the expression of TNF-α induced in THP-1 cells by gonococci. The CPP showed no cytotoxicity towards human THP-1 cells. Based on these promising results, future studies will focus on testing of CPP in the presence of other types of host cells and exploration of structural modifications of the CPP that could decrease its susceptibility to proteolysis and increase its potency.

Bonding of resin luting cements to dentine after casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) treatment

ObjectiveTo determine whether the application of casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) in the proprietary paste to dentine would affect the subsequent bonding of resin-based adhesive luting cements. MethodsFlat mid-coronal occlusal dentine surfaces of extracted human molars were prepared and randomly divided into three groups with different treatment periods of CPP–ACP-containing paste, Tooth MousseTM, i.e., no treatment; 5min; or 5 days. Resin composite blocks were luted using either Variolink N, Panavia F2.0, Rely X U100, or Clearfil SA Luting, following the manufacturers׳ instructions. After storage in 100% relative humidity condition at 37°C for 24h, the bonded assemblies were sectioned perpendicular to the interface in x and y directions, obtaining stick-shaped specimens, to assess the adhesion using a microtensile bond strength test. Fractography and micromorphology of resin cement–dentine interface were examined under a SEM. ResultsDentine bond strengths of Variolink N and Rely X U100 appeared to be similar for all tested groups. Clearfil SA Luting showed a decrease of bond strength with a strong tendency for adhesive failure between resin cement and dentine following the CPP–ACP application. An increase of bond strength was observed for Panavia F2.0 bonded to CPP–ACP-treated dentine. Micromorphological evaluation revealed intimate interfacial contact and formation of pronounced resin tags for Variolink N and Panavia F2.0, regardless of CPP–ACP treatment. For the self-adhesive luting materials tested, no distinct interaction zone between the resin cements and dentine could be observed and fewer resin tags were formed. Voids at the interface were detected for Clearfil SA Luting bonded to dentine following the treatment of CPP–ACP for both application times. ConclusionsPrior application of the CPP–ACP-containing paste to dentine compromised the bonding effectiveness of self-adhesive resin cements. However, with separate pretreatment steps to the tooth surface, dentine adhesion of conventional resin cements seemed not to be negatively influenced by CPP–ACP application.

Impacts of chemical crop protection applications on related CO2 emissions and CO2 assimilation of crops

A major global challenge is to provide agricultural production systems that are able to sustain growing demands for food, feed, fibre and renewable raw materials without exacerbating climate change. Detailed and reliable data on the CO(2) balance of different agricultural management activities and inputs as a basis to quantify carbon footprints of agriculture are still lacking. This study aims to fill this gap further by quantifying the net balance of emitted and assimilated CO(2) due to the application of crop protection treatments on the farm, and by assessing their partial contribution to GHG emissions and mitigation in agriculture. The study focuses on key agricultural crops including wheat, corn, oilseeds and sugar crops. The final CO(2) balance, considering GHG emissions due to on-farm CPP treatment in comparison with CO(2) storage in additional biomass, CO(2) protected with respect to agrotechnical inputs and land inputs and CO(2) saved with respect to associated global land use changes, is positive and may reach multiples of up to nearly 2000. The results highlight the importance of the positive yield effects of the CPP programme applications on the farm, resulting in additional assimilated biomass at the farm level and less land use changes at the global level, and thus lower pressure on environmentally important indicators of overall agricultural sustainability.

Surgical treatment of choroid plexus tumors

The purpose of this study is to evaluate the results of microsurgical treatment for choroid plexus tumors (CPT) in adult patients. From 1990 to 2008, 14 patients >18 years were treated at our institution for CPT, including seven males and seven females with a mean age of 46 years. Mean follow-up was 40 months. We reviewed the respective patients' charts, operative, and follow-up notes. Telephone interviews were performed as necessary. Neurological status was determined using the Karnofsky performance index pre- and post-operatively and at last follow-up. This series includes 12 plexus papillomas (CPP) and two atypical plexus papillomas (APP). Ten tumors were located in the fourth ventricle, two tumors in the cerebellopontine angle, one growth each in the third and lateral ventricle. In 12 cases, a complete tumor resection was achieved. No recurrence was observed in these cases. Two recurrent CPP were diagnosed 11 and 25 years after the initial surgery. Brain stem infiltration prevented a complete tumor removal in one case. In the other, the degree of resection after the first operation could not be ascertained. None of the patients received adjuvant chemo- or radiotherapy. In four patients (29%), a permanent ventricular-peritoneal shunt was necessary. Three patients initially presented with a Karnofsky index of 60 or below. During follow-up, three patients (21%) never improved beyond a Karnofsky index of 60. Surgery aiming radical excision is the key to successful treatment of CPP and APP in adults. Postoperative outcomes may be less than satisfactory in some patients.

Effects of Calcium Phosphate Precipitation Method on Acid Resistance to Apatite Powder and Bovine Tooth

The aims of this study were to evaluate the effects of CPP method on the crystallinity of apatite powder and on the acid resistance of bovine enamel. Crystallinity degrees of apatite powder before and after CPP treatment were measured by powder X-ray diffraction analysis. Polished bovine enamel specimens treated with CPP method or NaF were immersed in a lactic acid solution for up to five days. The demineralized depth of enamel was measured with a surface roughness analyzer. XRD peaks became sharper after the CPP treatment, indicating an increased crystallinity of the apatite powder. The demineralized depth of bovine enamel treated with CPP method was shallower than that of enamel treated with NaF. Results of this study revealed that the CPP method increased the crystallinity of apatite powder and the acid resistance of enamel. Therefore, the CPP method would be useful not only for treating dentin hypersensitivity, but also for the prevention of dental caries.

Polycyclic aromatic hydrocarbons induce both apoptotic and anti-apoptotic signals in Hepa1c1c7 cells.

In this study we show that benzo[a]pyrene (B[a]P) and the cyclopenta polycyclic aromatic hydrocarbons (CP-PAH) cyclopenta[c,d]pyrene (CPP), benz[j]aceanthrylene (B[j]A) and benz[l]aceanthrylene (B[l]A) induce apoptosis in Hepa1c1c7 cells, as measured by fluorescence microscopy and flow cytometry. The compounds induced formation of the active form of caspase-3, cleavage of its intracellular substrate, poly(ADP-ribose)polymerase (PARP), and DNA fragmentation. B[j]A was found to be the most potent in inducing apoptosis, followed by B[a]P, CPP and B[l]A. All compounds increased expression of CYP1A1 with relative potencies B[j]A > B[a]P >> CPP > B[l]A, corresponding well with their relative apoptotic responses. alpha-Naphthoflavone (alphaNF), an inhibitor of CYP1A1, reduced the induced apoptosis. B[a]P and CP-PAH exposure also resulted in an accumulation of the tumour suppressor protein p53. No changes were observed in the protein levels of Bax and Bcl-2, whereas the anti-apoptotic Bcl-xl protein was down-regulated, as judged by western blot analysis. Fluorescence microscopic analysis revealed a translocation of p53 to the nucleus and of Bax to the mitochondria. Furthermore, caspase-8 was activated and Bid cleaved. Interestingly, the levels of anti-apoptotic phospho-Bad (Ser155 and Ser112) had a biphasic increase after B[a]P or CPP treatment. Whereas alphaNF markedly reduced the activation of B[a]P to reactive metabolites, as measured by covalent binding to macromolecules, it did not inhibit the up-regulation of phospho-Bad. Neither of the compounds triggered apoptosis in primary cultures of rat lung cells (Clara cells, type 2 cells and lung alveolar macrophages), possibly due to a lack of CYP1A1 induction. In conclusion, B[a]P and the CP-PAH induced apoptotic as well as anti-apoptotic signals in Hepa1c1c7 cells.

Ionic composition and osmolality of paddlefish ( Polyodon spathula , Acipenseriformes) seminal fluid

Changes in ionic composition as Na+,K+, Ca2+ and Mg2+, osmolality inseminal fluid, percentage of motile spermatozoaand velocity were investigated in response toCPP and different dosage of LHRHa. The lowestvelocity of sperm was observed after use CPPtreatment. The velocity of spermatozoa,significant main effect of the treatment(P < 0.0001) and the time of sperm collection(P < 0.0104) were evaluated. The osmolality ofseminal fluid was different betweenexperimental groups of LHRHa (48.0–62.7mOsmol.kg−1) and CPP (33.0–46.3mOsmol.kg−1) treatments. The osmolalitywas significantly higher on the first day andone-half, then declined on day three, rangingfrom 33.0 to 62.7 mOsmol.kg−1. Analysisof variance showed significant main effects ofthe treatment (P < 0.0001) and the time ofsperm collection (P < 0.0002) on the osmolalityof seminal fluid. The level of Na+ andK+ ion was different between experimentalgroups of LHRHa and CPP treatment. The highestconcentration of 11.11 mmol.l−1 wasobserved at Na+ ion. Then theconcentrations declined on the level 1.56, 0.52and 0.36 mmol.l−1 for K+, Ca2+and Mg2+ ions, respectively. There werehighly positive correlations between osmolalityof seminal fluid and dosage of LHRHa treatment(r = 0.84), velocity of spermatozoa andosmolality of seminal fluid (r = 0.57) andosmolality of seminal fluid and Na+concentration at seminal fluid (r = 0.70).Injection with LHRHa increased quality of spermas velocity of sperm, level of Na+,K+ and osmolality at seminal fluidcompared to CPP treatments.

Discrimination reversal conditioning of an eyeblink response is impaired by NMDA receptor blockade.

In the present study we examined the effects of the specific NMDA receptor antagonist CPP on discrimination reversal learning in rabbits. We report two primary findings. First, the institution of NMDA receptor blockade had no effect on a learned discrimination. Second, after stimulus reversal, CPP treatment impaired acquisition of the discrimination reversal. This impairment manifested itself early in training as a retardation in acquisition of a CR to the new CS+ and late in training as an inability to suppress responsiveness to the new CS-. Given the comparability of the present results with previously published results for phenytoin-treated rabbits, we suggest that the effects of phenytoin on learning in this paradigm is at least in part mediated by its effects on NMDA receptors. We further suggest that these findings emphasize the need to better define the role of NMDA receptor activation and hippocampally-mediated circuits in a variety of associative learning paradigms.

Estrogen and NMDA receptor antagonism: effects upon reference and working memory

Since both estrogen and NMDA receptor antagonists act on the hippocampus CA1 region and behaviorally affect hippocampal memory tasks, we examined how estrogen depletion (ovariectomy) and NMDA receptor antagonism interact upon spatial memory of the mouse. After ovariectomy or sham operation, mice were given a 2-week recovery before behavioral tests began under the influence of vehicle or (±)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP 2, 5 and 10 mg/kg) intraperitoneal injections. CPP is a competitive, full NMDA receptor antagonist. Spatial reference memory was tested by the water maze, spatial working memory was tested by the radial arm maze, while overall locomotive activity was monitored by the Y-maze. Results from the water maze and the Y-maze did not show any spatial reference memory or activity differences between sham-operated and ovariectomized mice. The radial arm maze, however, highlighted some working memory differences between intact and ovariectomized mice. CPP treatment impaired dose dependently –the performance of ovariectomy and sham-operated mice equally on both water maze and radial arm maze, while the drug had no effect on Y-maze performance. These results suggest that short term estrogen deprivation has no effect upon spatial –reference memory, while it impairs spatial working memory. This effect is probably not mediated by NMDA receptors.

Effect of cerebral hypoxia on NMDA receptor binding characteristics after treatment with 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) in newborn piglets

Previous studies have shown that hypoxia modifies the NMDA receptor/ion channel complex in cortical brain cell membranes of newborn piglets. The present study tests the hypothesis that blockade of the glutamate recognition site of the NMDA receptor with the competitive antagonist 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) prevents modification of the receptor during hypoxia. Twenty seven anesthetized, ventilated newborn piglets were randomized into four groups: 7 normoxic (Nx), 6 CPP-treated normoxic (CPP-Nx), 8 hypoxic (Hx) and 6 CPP-treated hypoxic (CPP-Hx). Treatment groups received CPP 2 mg/kg i.v. The CPP-Hx group received CPP 30 min prior to hypoxia, which was induced by lowering the FiO2 to 5-7% for 1 h. Physiologic data showed no change in heart rate, blood pressure, arterial blood gas values, glucose or lactate following CPP administration. During hypoxia there was a significant decrease in PaO2, pH and an increase in lactate compared to baseline values. The CPP-Hx group had significantly higher lactate levels than the Hx group during hypoxia. P2 membrane fractions were prepared and thoroughly washed. Characteristics of the NMDA receptor ion channel were determined by [3H]MK-801 binding assays and characteristics of the glutamate recognition site by specific NMDA-displaceable [3H]glutamate binding assays. Brain tissue ATP and PCr levels confirmed tissue hypoxia, and were not preserved by CPP administration. [3H]MK-801 binding assays revealed that CPP treatment attenuated the hypoxia-induced decrease in the number of receptors (Bmax) and receptor binding affinity (Kd) during hypoxia. CPP treatment also decreased receptor affinity (increased Kd) for [3H]MK-801 binding during normoxia and hypoxia. Assays of [3H]glutamate binding revealed that hypoxia decreased both the Bmax and the Kd of the NMDA receptor for [3H]glutamate and both were preserved by CPP treatment prior to hypoxia. CPP had no effect on [3H]glutamate Bmax or Kd during normoxia. We conclude that hypoxia decreases the Bmax and Kd of the NMDA receptor glutamate recognition site for [3H]glutamate and the ion channel site for [3H]MK-801 in newborn piglets. These changes are prevented by CPP administration prior to hypoxia. The different effects of CPP binding during normoxia and hypoxia suggest a use-dependent mechanism for CPP binding during hypoxia, possibly through an hypoxia-induced alteration of the high-affinity binding site for CPP. During both normoxia and hypoxia CPP binding appeared to induce a conformational change in the receptor causing a decrease in binding affinity for [3H]MK-801. CPP administration did not preserve brain tissue ATP or PCr levels during hypoxia and may alter cellular metabolism in addition to its action at the NMDA receptor. However, even with depletion of the energy precursors ATP and PCr, and with higher lactate levels in the CPP-Hx group, CPP was able to maintain NMDA receptor binding characteristics during hypoxia and may decrease excitotoxic cellular damage from hypoxia.

Effect of cerebral hypoxia on NMDA receptor binding characteristics after treatment with 3-(2-carboxypiperazin-4-yl) propyl-1-phosphonic acid (CPP) in newborn piglets

Previous studies have shown that hypoxia modifies the NMDA receptor/ion channel complex in cortical brain cell membranes of newborn piglets. The present study tests the hypothesis that blockade of the glutamate recognition site of the NMDA receptor with the competitive antagonist 3-(2-carboxypiperazin-4-yl)propyl-l-phosphonic acid (CPP) prevents modification of the receptor during hypoxia. Twenty seven anesthetized, ventilated newborn piglets were randomized into four groups: 7 normoxic (Nx), 6 CPP-treated normoxic (CPP-Nx), 8 hypoxic (Hx) and 6 CPP-treated hypoxic (CPP-Hx). Treatment groups received CPP 2 mg/kg i.v. The CPP-Hx group received CPP 30 min: prior to hypoxia, which was induced by lowering the FiO 2, to 5–7% for 1 h. Physiologic data showed no change in heart rate, blood pressure, arterial blood gas values, glucose or lactate following CPP administration. During hypoxia there was a significant decrease in PaO 2, pH and an increase in lactate compared to baseline values. The CPP-Hx group had significantly higher lactate levels than the Hx group during hypoxia. P 2 membrane fractions were prepared and thoroughly washed. Characteristics of the NMDA receptor ion channel were determined by [ 3H]MK-801 binding assays and characteristics of the glutamate recognition site by specific NMDA-displaceable [ 3H]glutamate binding assays. Brain tissue ATP and PCr levels confirmed tissue hypoxia, and were not preserved by CPP administration. [ 3H]MK-801 binding assays revealed that CPP treatment attenuated the hypoxia-induced decrease in the number of receptors ( B max) and receptor binding affinity ( K d) during hypoxia. CPP treatment also decreased receptor affinity (increased K d) for [ 3H]MK-801 binding during normoxia and hypoxia. Assays of [ 3H]glutamate binding revealed that hypoxia decreased both the B max and the Kd of the NMDA receptor for [ 3H]glutamate and both were preserved by CPP treatment prior to hypoxia. CPP had no effect on [ 3H]glutamate B max or K d during normoxia. We conclude that hypoxia decreases the B max and K d of the NMDA receptor glutamate recognition site for [ 3H]glutamate and the ion channel site for [ 3H]MK-801 in newborn piglets. These changes are prevented by CPP administration prior to hypoxia. The different effects of CPP binding during normoxia and hypoxia suggest a use-dependent mechanism for CPP binding during hypoxia, possibly through an hypoxia-induced alteration of the high-affinity binding site for CPP. During both normoxia and hypoxia CPP binding appeared to induce a conformational change in the receptor causing a decrease in binding affinity for [ 3H]MK-801. CPP administration did not preserve brain tissue ATP or PCr levels during hypoxia and may alter cellular metabolism in addition to its action at the NMDA receptor. However, even with depletion of the energy precursors ATP and PCr, and with higher lactate levels in the CPP-Hx group, CPP was able to maintain NMDA receptor binding characteristics during hypoxia and may decrease excitotoxic cellular damage from hypoxia.

IGF-1 AND IGFBP-3 REMAIN HIGH AFTER TREATMENT-INDUCED PUBERTAL ARREST IN GIRLS WITH CENTRAL PRECOCIOUS PUBERTY (CPP)

Insulin like growth factor-1 (IGF-1) increases during normal adolescence and in CPP secondary to the rise in sex steroids and GH. Treatment of CPP using GnRH analog suppresses GH as well as gonadotropins. We examined IGF-1 and its major binding protein-IGFBP-3 in sera of ten girls diagnosed with CPP, before and during the first 3 months of GnRH analog therapy. Serum IGF-1 was increased in patients with CPP as compared with controls (48.8 + 6.5 vs 23.1 + 4.9 nmol/L, p < 0.01). GnRH analog therapy caused serum E2 levels to return to prepubertal levels in all 10 patients, whereas serum IGF-1 levels decreased minimally after one (43.2 ± 5.6 nmol/L), two (42.3 ± 6.4 nmol/L), and three (44.1 ± 7.2 nmol/L) months of therapy. Serum IGFBP-3 concentrations measured using IRMA were also higher in CPP compared with controls (4.7 ± 0.37 vs 3.7 ± 0.42 mg/L p < 0.01). These differences were also evident when all IGF binding proteins were measured by Western ligand blotting. GnRHa therapy caused a small and insignificant decrease in serum IGFBP-3 levels after one (4.57 ± 0.33 mg/L), two (4.48 ± 0.4 mg/L) and three (4.42 ± 0.3 mg/L) months of therapy. This lack of suppression of both IGF-1 and IGFBP-3 despite therapy which halts pubertal progression and reverses GH secretion underscores the complex regulation of IGF-1 and its binding proteins during puberty.