Transient rise in nuclear calcium concentration is implicated in the regulation of events controlling gene expression. Mechanism by which calcium is transported to the nucleus is vehemently debated. Inositol 1,4,5-trisphosphate (InsP3) and inositol-1,3,4,5-tetrakisphosphate (InsP4) receptors have been located to the nucleus and their role in nuclear calcium signaling has been proposed. Outer nuclear membrane was separated from the inner membrane. The two membrane preparations were, as best as possible, devoid of cross contamination as attested by marker enzyme activity, Western blotting with antilamin antibody, and electron microscopy. InsP4 receptor and Ca(2+)-ATPase were located to the outer nuclear membrane. InsP3 receptor was located to the inner nuclear membrane. ATP or InsP4 induced nuclear calcium uptake. External free calcium concentration, in the medium bathing the nuclei, determined the choice for ATP or InsP4-mediated calcium transport. We present a mechanistic model for nuclear calcium transport. According to this model, calcium can reach the nucleus envelope either by the action of ATP or InsP4. However, the calcium release from the nucleus envelope to the nucleoplasm is mediated by InsP3 through the activation of InsP3 receptor, which is located to the inner nuclear membrane. The action of InsP3 in this process was instantaneous and transient and was sensitive to heparin.

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Two parent clones of a gamma-hydroxybutyrate (GHB) receptor, C12K32 and GHBh1, were isolated from a human frontal cortex cDNA library. The two clones differ by a deleted cytosine in C12K32. CHO cells transfected with either C12K32 or GHBh1 responded positively to submicromolar GHB stimulation. However, unlike C12K32, GHBh1 desensitizes rapidly on application of low concentrations of GHB. GHB receptor properties were then studied on C12K32 expressed in CHO cells. C12K32 bound GHB with a Kd of 114 nM and has no affinity for GABA or glutamate. GHB and NCS-382 displaced [3H]GHB with an IC50 of 53 +/- 8 and 120 +/- 18 nM, respectively. In patch-clamp experiments, GHB induced a dose-dependent response with an EC50 of 130 nM. This response was antagonized by NCS-382, was not reproduced by GABA, and was sensitive to the addition of GTP-gamma-S in the recording pipette. CHO cells transfected with C12K32 exhibited GTPgamma-35S binding with an EC50 of 462 nM for GHB and an IC50 of 2.9 microM for NCS-382. The present data led to the conclusion that both C12K32 and GHBh1 are two closely related isoforms of a human GHB receptor, GHBh1, that is described in the databank as the GPCR 172A.

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Through the development of a new class of unnatural ornithine derivatives as bioisosteres of arginine, we have designed an orally active peptidomimetic antagonist of neuropeptide FF receptors (NPFFR). Systemic low-dose administration of this compound to rats blocked opioid-induced hyperalgesia, without any apparent side-effects. Interestingly, we also observed that this compound potentiated opioid-induced analgesia. This unnatural ornithine derivative provides a novel therapeutic approach for both improving analgesia and reducing hyperalgesia induced by opioids in patients being treated for chronic pain.

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Spray drying of wheys and derivatives. Spray drying is one of the most convenient technique for producing conventional milk powders. However, its use for the dehydration of new and diversified products, such as whey and derivatives, is rather empirical and generally limited by the appearance of several problems such as the sticking and the caking of generated powders. The origin of these problems is linked to complex interactions between several factors: physical properties of the product (viscosity, relative humidity and hygroscopicity), its composition (mineral, protein and carbohydrate contents and pH) and process parameters (outlet and inlet temperatures, heating and cooling rates and agitation). This review paper highlights the research works that deal with the impact of these factors on spray drying. In particular, we focus on how these factors affect water activity, glass transition and lactose crystallization, the main important variable to be controlled for better optimization of spray drying process of whey derivative products. Lactose / water / crystallization / spray drying / whey Résumé-Le séchage par atomisation s'est imposé à l'échelle industrielle pour le traitement des produits laitiers conventionnels. Son adaptation à la déshydratation des produits nouveaux et diversifiés, tels que les lactosérums et perméats, se fait de manière empirique et pose un certain nombre de problèmes, en particulier le collage des produits en tour de séchage et leur mottage à l'état de poudre. Les facteurs à l'origine de ces deux phénomènes sont multiples et interdépendants : propriétés physiques des produits (viscosité, a w et hygroscopicité), composition des produits (teneur et nature minérale et protéique, forme du lactose et pH) et paramètres du procédé (températures d'entrée et de sortie, vitesses de chauffage et de refroidissement et agitation). Le lien entre ces différents facteurs est traité dans cette revue au travers de leur impact sur la dynamique de l'eau et, par conséquent, sur la cristallisation du lactose. Les connaissances actuelles dans ce domaine dérivent des résultats obtenus sur des mélanges « modèles ». Des travaux sur produits complexes, prenant en compte l'interdépendance de ces différents facteurs sont indispensables pour prédire et maîtriser les conditions permettant d'obtenir une poudre de bonne stabilité. Lactose / eau / cristallisation / séchage par atomisation / lactosérum

Although opiates represent the most effective analgesics, their use in chronic treatments is associated with numerous side effects including the development of pain hypersensitivity and analgesic tolerance. We recently identified a novel orally active neuropeptide FF (NPFF) receptor antagonist, RF313, which efficiently prevents the development of fentanyl-induced hyperalgesia in rats. In this study, we investigated the properties of this compound into more details. We show that RF313 exhibited a pronounced selectivity for NPFF receptors, antagonist activity at NPFF1 receptor (NPFF1R) subtype both in vitro and in vivo and no major side effects when administered in mice up to 30 mg/kg. When co-administered with opiates in rats and mice, it improved their analgesic efficacy and prevented the development of long lasting opioid-induced hyperalgesia. Moreover, and in marked contrast with the dipeptidic NPFF receptor antagonist RF9, RF313 displayed negligible affinity and no agonist activity (up to 100 μM) toward the kisspeptin receptor. Finally, in male hamster, RF313 had no effect when administered alone but fully blocked the increase in LH induced by RFRP-3, while RF9 per se induced a significant increase in LH levels which is consistent with its ability to activate kisspeptin receptors. Altogether, our data indicate that RF313 represents an interesting compound for the development of therapeutic tools aiming at improving analgesic action of opiates and reducing adverse side effects associated with their chronic administration. Moreover, its lack of agonist activity at the kisspeptin receptor indicates that RF313 might be considered a better pharmacological tool, when compared to RF9, to examine the regulatory roles of RF-amide-related peptides and NPFF1R in reproduction.