Genetic characterization of an α-specific gene responsible for sexual agglutinability in Saccharomyces cerevisiae: mapping and gene dose effect

Summary A recessive ag1 mutation leads to specific defect in sexual agglutinability specifically in cells of the yeast Saccharomyces cerevisiae. The cryptopleurine resistance gene cry^R 1, closely linked to the mating type locus, was used to select / strains which emerged from / strains by mitotic nonreciprocal recombination, to genetically analyse ag1, since ag1 is expressed only in mating type. The ag1 gene was found to be linked to the centromere tightly, to met3 at 4.4 cM, and to ilv3 at 12 cM on chromosome X. Sexual agglutinability of cells was shown to be dependent on the dose of the AG1 gene, using / isogenic strains carrying AG1/AG1, AG1/ag1 or ag1/ag1. The sst2-1 mutation did not suppress the ag1 mutation. Based on these results, function of the AG1 gene is discussed.Abbreviations cM centimorgan - FDS first division segregation - NPD nonparental ditype - PD parental ditype - SDS second division segregation - TT tetratype     

α 2-Adrenoceptors activate dihydropyridine-sensitive calcium channels via Gi-proteins and protein kinase C in rat portal vein myocytes

The presence of functional ₂-adrenoceptors was investigated in isolated smooth muscle cells from rat portal vein using the nystatin-perforated patch-clamp technique. The free cytoplasmic calcium concentration ([Ca²⁺]_i) was estimated using emission from the dye Fura-2. Activation of ₂-adrenoceptors by clonidine (an ₂-adrenoceptor agonist) or noradrenaline (a non-selective -adrenoceptor agonist), both in the presence of 0.1 M prazosin to block ₁-adrenoceptors, caused a slow and sustained increase in [Ca²⁺]_i which was inhibited by 0.1 M rauwolscine (an ₂-adrenoceptor antagonist). A similar Ca²⁺ response was obtained with oxymetazoline (a selective _2A-adrenoceptor agonist) suggesting that the increase in [Ca²⁺]_i resulted from activation of the _2A-adrenoceptor subtype. The increase in [Ca²⁺]_i did not occur in calcium-free solution or in the presence of oxodipine (a voltage-dependent calcium channel blocker), indicating that it depended on a calcium influx. The _2A-adrenoceptor-activated calcium influx was unchanged after complete release of the stored calcium induced by applications of ryanodine and caffeine. In addition, no accumulation of inositol trisphosphate was detected in the presence of 0.1 M prazosin. Taken together, these results indicate that _2A-adrenoceptor activation does not stimulate phosphoinositide turnover and subsequent calcium release from intracellular stores. Wholecell patch-clamp experiments showed that _2A-adrenoceptor activation promoted calcium influx through voltage-dependent L-type channels. Concomitant with calcium influx, _2A-adrenoceptor activation induced a 10- to 15-mV depolarization. Similar effects on both calcium channel current and [Ca²⁺]_i were obtained with mastoparan, an activator of Gi-proteins. Activation of calcium influx by both _2A-adrenoceptors and mastoparan was reduced by treatment with pertussis toxin and GF 109203X (a protein kinase C inhibitor). These data suggest that activation of protein kinase C through a transduction pathway involving Gi-proteins phosphorylates voltage-activated L-type calcium channels and thus, increases their opening probability.     

α1-Proteinase inhibitor and mucus proteinase inhibitor in human lung emphysema

Summary The role of the antiproteases ₁-proteinase inhibitor (₁PI) and mucus proteinase inhibitor (MPI) in human lung emphysema was investigated by measuring their amount and functional activity against trypsin, leukocyte elastase, and pancreatic elastase in the bronchoalveolar lavage fluid (BALF). In addition, leukocyte elastase was quantified in the lavage samples by measuring the concentration of the elastase-₁Pl-complex. The study population consisted of 38 patients (5 nonsmokers, 8 former smokers, 25 smokers) with aquired emphysema (i.e., emphysema which is not caused by ₁PI deficiency), and 44 individuals (16 nonsmokers, 8 former smokers, 20 smokers) without emphysema. No differences were found between patients with and without emphysema in the activities of ₁PI and MPI, or in the concentration of ₁PI The concentration of MPI was significantly higher in the BALF of patients with emphysema than in that of patients without emphysema (p = 0.025). A significantly higher concentration of elastase-₁PI complex was found in patients with emphysema than in those without emphysema (p = 0.041). This finding could reflect the higher proteinase burden to which patients with emphysema are exposed. The increase of MPI in lavage fluid of patients with emphysema seems to be the result of increased production in emphysematous lungs. However, it remains unclear why patients develop emphysema while showing an increased content of MPI.Abbreviations ₁PI ₁-proteinase inhibitor - BALF bronchoalveolar lavage fluid - ELISA enzyme-linked immunosorbent assay - LEIC leukocyte elastase inhibitory capacity - MPI mucus proteinase inhibitor - PEIC pancreatic elastase inhibitory capacity - TIC trypsin inhibitory capacity     

Expression and ligand-binding function of the integrin α4β1 (VLA-4) on neural-crest-derived tumor cell lines

Human neural-crest-derived tumor cell lines, including three neuroblastomas, an astrocytoma, a glioblastoma, a rhabdomyosarcoma and a melanoma were screened for the expression of the integrin ₄₁ (VLA-4). The neuroblastomas IMR-32 and SK-N-SH, the astrocytoma 131-INI, the glioblastoma Fogerty and the rhabdomyosarcoma TE-671 expressed ₄₁ as determined by cytofluorometry and immunoprecipitation. Another neuroblastoma line, LA-N-1, did not express ₄₁. Analysis of immunoprecipitated ₄₁ showed that the ₄ subunit from the various cell types differed in relative molecular weight (M _r ). The variability in the observed M _r could be accounted for by differences in the levels of N-linked glycosylation. The observed variability in M _r did not appear to affect function since intact cells and solubilized ₄₁ bound to a synthetic peptide identical in sequence to the CS-1 region of the alternatively spliced IIICS domain of fibronectin, a known ₄₁, ligand.     

Glomerulonephritis as late manifestation of severe αl-antitrypsin deficiency

An association of ₁-antitrypsin deficiency with glomerulonephritis is rare and has so far been observed only in children or young adults. We report a 63-year-old man with severe ₁-antitrypsin deficiency associated with pulmonary emphysema, cirrhosis of the liver, and mesangioproliferative glomerulonephritis with nephrotic syndrome. Following initial presentation with nephropathy, further work-up revealed ₁-antitrypsin deficiency of proteinase inhibitor Z. In the absence of glomerular ₁-antitrypsin deposits the relationship between renal disease and ₁-antitrypsin deficiency remains unclear. ₁-Antitrypsin deficiency should be considered in adults with abnormal renal function and chronic liver disease.Abbreviations A1AT ₁-antitrypsin - Pi proteinase inhibitor     

Interferon-α activates cytotoxic function but inhibits interleukin-2-mediated proliferation and tumor necrosis factor-α secretion by immature human natural killer cells

Natural killer (NK) cells play an important role in host defense mechanisms against infection and neoplasia. Interferon- (IFN-) has been shown to activate NK cells and to augment their cytotoxic activity, albeit its role in the maturation pathway of NK cells has not been elucidated. The present study examined whether IFN- activates the immature NK subset (Free cells) to become cytotoxic and also ascertained whether IFN- uses the same pathway of activation as that mediated by interleukin-2 (IL-2). Incubation of sorted Free cells overnight with IFN- resulted in augmentation of their cytotoxic function against NK sensitive target cells. The enhanced cytotoxic activity was not accompanied by a new recruitment of NK-target binder cells but by an increase in the frequency of killer cells in the conjugate fraction. Activation of the Free subset by IFN- resulted in upregulation of CD69, CD11b, and CD2 surface expression and stimulated secretion of IFN-. Unlike IL-2, IFN- did not stimulate the Free cells to proliferate or secrete TNF- and activation of cytotoxicity and modulation of surface antigens by IFN- were independent of TNF-. The failure of IFN- to stimulate secretion and proliferation by Free cells appeared to be mediated by negative signals. This was corroborated in experiments demonstrating that when Free cells were cultured with both IFN- and IL-2, a significant inhibition was observed for both the IL-2 dependent secretion of TNF- and proliferation. These results demonstrate that IFN- serves as both an activator and a regulator of NK function. Further, activation of the immature Free NK cells by IL-2 and IFN- proceeds by TNF--dependent and independent pathways, respectively. The findings also support our contention that the mechanism of activation of the cytotoxic machinery of NK cells is not linked to the mechanism of activation of cytokine secretion and/or proliferation.Abbreviations used IFN interferon - IL interleukin - PBL peripheral blood leukocytes - PE phycoerythrin - PE-GAM PE-conjugated Fab2 goat anti-mouse IgG - NK natural killer - NRS normal rabbit serum - TNF tumor necrosis factor - FCS fetal calf serum - FITC fluorescein isothiocyanate - PBS phosphate-buffered saline - MACS magnetic cell sorting - ELISA enzyme-linked immunosorbent assay - BSA bovine serum albumin - PKC protein kinase C - mAb monoclonal antibody - PBMC peripheral blood mononuclear cells - BCLL B-chronic lymphocytic leukemia - E effector - T target     

Presence of two isoforms of Na,K-ATPase with different pharmacological and immunological properties in the rat kidney

Previous studies have demonstrated the presence of two populations of Na,K-ATPase with distinct kinetic, pharmacological and immunological characteristics along the rabbit nephron, indicating that the proximal segments of the nephron express exclusively the ₁ isoform of the catalytic subunit, whereas the collecting duct expresses an ₃-like isoform. Because pharmacological studies have shown the existence of two populations of Na,K-ATPase with different sensitivities to ouabain in the rat cortical collecting duct, which may result from the presence in the same nephron segment of the two isoforms demonstrated in the different segments of the rabbit nephron, the present study was undertaken to characterize the properties of Na,K-ATPase along the rat nephron. Results indicate that each segment of the rat nephron contains two subpopulations of Na,K-ATPase: a component highly sensitive to ouabain (IC₅₀ 5.10^–6 M) which is recognized by an anti- ₃ antibody and another moiety of lower affinity for ouabain (IC₅₀ 5.10^–4 M) which is recognized by an anti- ₁ antibody. Whether these two subpopulations correspond to different isoforms of the subunit of Na,K-ATPase ( ₁ and ₃-like) remains to be determined.     

β subunits determine the time course of desensitization in rat α3 neuronal nicotinic acetylcholine receptors

Standard two-electrode voltage-clamp techniques were used to investigate some of the pharmacological and functional properties of two types of rat neuronal nicotinic acetylcholine receptors expressed in Xenopus oocytes after pairwise injection of 34 or 32 mRNAs. Currents of several A amplitude were elicited by fast application of micromolar concentrations of either acetylcholine (ACh) or 1,1-dimethyl-4-piperazine (DMPP). The activation of either receptor type by DMPP showed cooperativity (Hill coefficient, n1.7) with a half-maximal activation concentration (EC₅₀) of 15–30 M. In 34 receptors, ACh displayed cooperativity (n=1.8) but was less efficacious than DMPP, yet its EC₅₀ was about equal to that of DMPP. Finally, in 32 receptors, ACh was much less efficacious and had a much lower EC₅₀. Desensitization induced by either DMPP or ACh was slow in 34 nicotinic ACh receptors but was rapid and extensive in 32 receptors, causing a significant proportion of the response to wane within the first few seconds of agonist application.     

Presence,activities, and molecular forms of cathepsin G,elastase,α 1-antitrypsin,andα 1-antichymotrypsin in bronchiectasis

The presence, activities, and molecular forms of the serine proteinases, elastase, and cathepsin G, and their endogenous inhibitors, ₁-antitrypsin and ₁-antichymotrypsin, were investigated in bronchoalveolar lavage (BAL) fluid of bronchiectasis patients divided into mild, moderate, and severe disease subgroups and compared to BAL fluid from healthy controls. Immunochemical characterization and quantitation were performed by Western immunoblot. The activities of elastase and cathepsin G were recorded spectrophotometrically using synthetic substrates. The results showed a significant difference in elastase and cathepsin G activities in BAL fluid of the three subgroups, revealing the following data—mild subgroup, 0.21±0.09 mU/g and 57.35±20.9 U/g; moderate subgroup, 1.87±1.12 mU/g and 89.24±31.4 U/g; and severe subgroup, 2.64±1.63 mU/g and 139.18±58.3 U/g, respectively—compared to those of the healthy control group, 0.09±0.03 mU/g and 50.96±16.5 U/g. Evidently, the protective shield of plasma-derived antiproteinases was sufficient in healthy subjects and, also, in mild cases of bronchiectasis, but not in cases of severe and moderate forms of bronchiectasis, in which free and catalytically active elastase and cathepsin G were detected. The serine proteinases inhibitors (serpins), ₁-antitrypsin and ₁-antichymotrypsin, have evidently been oxidized and/or proteolytically cleaved in the cases of moderate and severe bronchiectasis. The results indicate that insufficient endogenous downregulation of catalytically active elastase and cathepsin G in BALF leads to tissue injury, resulting in alterative and deformative processes in the bronchiectasis lung.Abbreviations used BAL bronchoalveolar lavage - BALF bronchoalveolar lavage fluid - BE bronchiectasis - ₁-AT ₁-antitrypsin - ₁-ACT ₁-antichymotrypsin - ECM extracellular matrix - CT computerized tomography - PMN polymorphonuclear leukocyte - NCM nitrocellulose membrane - SDS-PAGE sodium dodecyl sulfatepolyacrylamide gel electrophoresis - TBS Tris-buffered saline     

Differential secretion of TNF-α and IFN-γ by human peripheral blood-derived NK subsets and association with functional maturation

Natural killer cells can be separated into three major subsets (free, binder, and killer) based on their ability to bind and kill sensitive target cells. The nonbinder, nonkiller free cells are the most immature and can be activated to become binders and killers. Natural killer (NK) cells synthesize and secrete several cytokines that are intimately involved in NK activation. This study investigated the secretion of tumor necrosis factor-alpha (TNF-) and interferon-gamma (IFN-) by purified NK cells and NK subsets following activation by various stimuli. K562 target cells stimulated secretion of both TNF- and IFN- by both the binder and the killer subsets but not by the free subset. IFN- activated the secretion of IFN- only, whereas IL-2 activated the secretion of both TNF- and IFN- by the binder and killer subsets and secretion was augmented by the addition of K562 to the cultures. Phorbol myristate acetate (PMA) and ionophore stimulated TNF- and IFN- secretion in both the binder and the killer subsets, though IFN- secretion was more pronounced in the binder subset. Activation of TNF- and IFN- secretion was dependent on de novo protein synthesis. Analysis at the single-cell level demonstrated that the binder subset had the highest frequency of cells secreting IFN-. These results demonstrate that both the binder and the killer subsets can be activated to secrete TNF- and IFN-, whereas the free NK subset secretes little or no TNF- and IFN- following activation. These data suggest that the ability of NK cells to secrete TNF- and IFN- following activation correlates with the functional stage of maturation of NK cells.     

Behavior of soluble HLA class I antigens in patients with chronic hepatitis C during interferon therapy: An early predictor marker of response?

Soluble HLA class I antigens (sHLA-I), ₂-microglobulin ( ₂-.) and alanine aminotransferase (ALT) serum levels have been evaluated in 16 patients affected by chronic hepatitis C treated for six months with recombinant interferon- (rIFN-, 3 MU three times a week). The predictor role of sHLA-I and ALT modifications with respect to the response to rIFN- therapy was also evaluated. Six patients responded (group 1), five patients relapsed following an initial response (group 2), and five did not respond to rIFN- treatment (group 3). The baseline serum levels of sHLA-I and ₂- were significantly higher in all three groups of HCV-positive patients with respect to HCV-negative controls (P<0.05). A significant increase of sHLA-I serum level with respect to baseline value (P<0.001) was observed in group 1 patients after two weeks of rIFN- treatment. sHLA-I serum level then decreased, although remaining steadily and significantly increased with respect to baseline (P values ranging from 0.05 to 0.01) in the following five months and then returned to baseline one month after the end of rIFN- administration. No significant variations of ₂- serum levels were detected throughout the observation period. In group 1 patients ALT serum levels significantly decreased after two weeks of rIFN- treatment (P<0.001) and then remained in the normal range throughout the observation period. In the other two groups of patients no relevant variations of sHLA-I and ₂- serum levels were found during and after rIFN- therapy. The modifications of sHLA-I serum levels discriminate, as a single marker, group 1 patients from group 2 and 3 patients after two weeks of rIFN- treatment (P<0.003). The association of sHLA-I and ALT modifications improves the discriminant power and leads to a complete differentiation of the three groups of patients after four weeks of rIFN- treatment (P<0.0001). If confirmed in a larger series of patients, these results will provide a useful marker to predict which patients affected by chronic hepatitis C will respond to treatment and will help to avoid their ineffective treatment with an expensive and potentially harmful drug.     

The effect of an α-ketoglutarate-pyridoxine complex on human maximal aerobic and anaerobic performance

Summary The administration of 30 mg/kg of body weight of an -ketoglutarate-pyridoxine complex (-KG compl; stoichiometric ratio -KG: pyridoxine 46.35 to 53.65) to trained non-athletic individuals increases max by 6% (p<0.005). The kinetics of the on- and off-responses at the onset and offset of a rectangular work load is not affected by the drug. Peak blood lactate concentration [La_b] following two supramaximal running work loads lasting 60 s and 132±4 s, respectively is significantly (p<0.05 and p<0.005) less after the -KG compl treatment (La_b=–1.1 and –2.7 mmol·1^–1, respectively) than in a control group. The half time (t1/2) of La disappearance from blood during recovery is unaffected by the -KG compl treatment (19.7 min vs 19.5 min). The increase in max and the corresponding decrease of [La_b] are not found after separate administration of either of the components of the complex. It is concluded that -KG complex stimulates aerobic metabolism, probably prompting mitochondrial reabsorption of -KG, which activates the malate-oxalacetate shuttle and the generation of high energy phosphates at the substrate level.     

In vitro response of mitochondrial succinate oxidase system to epinephrine in human blood lymphocytes from health individuals and patients with neurocirculatory dystonia

Activities of succinate dehydrogenase (SDH) and -glycerophosphate dehydrogenase (hyaloplasmic and mitochondrial: -GPDH_H and -GPDH_M) in peripheral blood lymphocytes, and the response of SDH activity to exogenous epinephrine in vitro (the epinephrine test) were studied in 20 healthy subjects and 46 patients with hypertensive neurocirculatory dystonia. Activities of SDH, -GPDH_H, and -GPDHM in blood lymphocytes and SDH adrenoreactivity in epinephrine test were higher in patients than in healthy controls. Treatment with hypotensive agents (isradipin and pyrroxan) moderated adrenoreactivity. Phytotherapy normalized the baseline activities of succinate oxidase system and -glycerophosphate pathway in blood lymphocytes.     

Is there a role for the tumor cell integrin αIIbβ3 and cytoskeleton in tumor cell-platelet interaction?

In vitro tumor cell-platelet interaction was examined using B16 amelanotic (B16a) melanoma cells. These tumor cells express the _IIb3-type cytoadhesin. Aggregation studies demonstrated that tumor cell surface _IIb3 mediates the recognition of platelets since pretreatment of tumor cells with antibody against _IIb3 prevents platelet-tumor cell interaction as well as platelet activation measured by aggregometry, platelet eicosanoid metabolism and ultrastructural analysis. In B16a cells, disruption of the microfilaments and intermediate filaments inhibits mobility of _IIb3 on the cell surface. Microtubules do not play a role in receptor mobility, because B16a cells do not possess well-defined microtubules in interphase and colchicine does not affect receptor mobility. Disruption of microfilaments or intermediate filaments results in an inhibition of tumor cell-platelet interaction as evidenced by aggregometry studies and ultrastructural analysis. We suggest that platelet interaction with tumor cells begins with _IIb3-mediated receptor recognition followed by not only platelet activation but also microfilament- and vimentin intermediate filament-dependent tumor cell activation.     

Mechanism of modulation of single sodium channels from skeletal muscle by the β 1-subunit from rat brain

We studied the molecular mechanism of the rat skeletal muscle -subunit (_I) gating kinetics modulation by the brain ₁-subunit by heterologous expression of single sodium channels from _I and ₁ in Xenopus laevis oocytes. Coexpression of ₁ reduced mean open time at –10 mV to 21% when compared to channels expressed by _I alone. Channels formed by _I exerted multiple openings per depolarization, which occurred in bursts, in contrast to the channels formed by the _I/₁ complex that opened in average only once per depolarizing voltage pulse. Macroscopic current decay (mcd), as evidenced by reconstructed open probability vs. time , was greatly accelerated by ₁, closely resembling mcd of sodium currents from native skeletal muscle. Generally was larger for channels expressed from the pure _I subunit.From our single channel data we conclude that ₁ accelerates the inactivation process of the sodium channel complex.     

Isoenzymes of γ-glutamyl transpeptidase in liver diseases

Summary A new method for the separation of isoenzymes of-glutamyl-transpeptidase is described, using electrophoresis on acetate cellulose gel and a developing solution composed by-glutamyl-naphthylamide, and a colored diazonium compound.The method permits the separation of up to four different isoenzymes, which we called-GT₁,-GT₂,-GT₃,-GT₄, the first two showing an electrophoretic migration similar to that of ₁- and ₂-globulins and the other two to that of-globulins.The present technique has proved its usefulness in detecting isoenzymes in serum with values of total-glutamyl-transpeptidase higher than 80 U/L.The application of this method in 52 patients with different types of biliary obstruction and hepatocellular damage has shown that it provides new possibilities in differential diagnosis.     

ω-Grammotoxin blocks action-potential-induced Ca2+ influx and whole-cell Ca2+ current in rat dorsal-root ganglion neurons

Field-potential stimulation of rat dorsal-root ganglion (DRG) neurons evoked action-potential-mediated transient increases in intracellular free calcium concentration ([Ca²⁺]_i) as measured by indo-1-based microfluorimetry. Field-potential-evoked [Ca²⁺]_i transients were abolished by tetrodotoxin, and their dependence on stimulus intensity exhibited an abrupt threshold. -Conotoxin GVIA (-CgTx, 100 nM) inhibited action-potential-mediated Ca²⁺ influx by 79%, while nitrendipine (1 M) had little effect. -Grammotoxin SIA (-GsTx, 267 nM), a peptide toxin purified from the venom of the tarantula spider, Grammostola spatulata, blocked action-potential-mediated Ca²⁺ influx as effectively as did -CgTx, suggesting that -GsTx blocks N-type Ca²⁺ channels. In contrast to block by -CgTx, the block produced by -GsTx reversed upon washout of the peptide. -GsTx (270 nM) blocked 80%, and -CgTx (1 M) blocked 64%, of whole-cell Ca²⁺ current (I _Ca) elicited by step depolarization to 0 mV from a holding potential of –80 mV. -GsTx completely occluded inhibition of I _Ca by -CgTx. However, when applied after -CgTx, -GsTx produced an additional inhibition of 27%, indicating that -GsTx also blocked a non-N-type Ca²⁺ channel. BayK8644 (1 M) elicited an increase in I _Ca in the presence of maximally effective concentrations of -GsTx, suggesting that -GsTx does not block L-type channels. Thus, -GsTx displays a selectivity for Ca²⁺ channel subtypes which should prove useful for studying Ca²⁺ channels and Ca²⁺-channel-mediated processes.     

Modulation of hematopoietic colony formation of stem cells in peripheral blood by anti-TGF-β in patients with severe immunosuppression

Summary The influence of transforming growth factor- (TGF-) on hematopoiesis has been evaluated by adding blocking antibodies against TGF- to colony forming assays (CFU-c). When optimum concentrations of recombinant growth factors, granulocyte-macrophage colony stimulating factor (GM-CSF), and interleukin-3 (IL-3) were added to stem cells from the peripheral blood of healthy individuals and certain patients with tumors or HIV infection, the anti-TGF- capable of blocking 5 ng/ml of active TGF- had no significant influence on erythroid or myeloid colony formation. However, in certain immunosuppressed individuals, anti-TGF- resulted in a significant decrease of erythroid colony formation and slight suppression of myeloid colony formation. The significant inhibition of hematopoiesis by plasma of HIV patients could be due to the presence of active forms of TGF-. The results of the blocking experiments are consistent with the concept that TGF- in low concentrations is essential for erythropoiesis and myelopoiesis but that higher levels of TGF- primarily inhibit erythropoiesis in vitro. TGF- serves as a coordinating factor when efficient recruitment of granulocytes and monocytes is more essential than erythropoiesis and stem cell growth.Abbreviations BFU-E burst forming unit-erythroid - CFC colony forming cells - CFU-GEMM colony forming unit-granulocyte/erythroid/macrophage/megacaryocyte - CFU-GM colony forming unit-granulocyte/macrophage - EPO erythropoietin - GM-CSF granulocyte/macrophage-colony stimulating factor - HIV human immunodeficiency virus - IL-1 interleukin-1 - IL-3 interleukin-3 - IMDM Iscove's Modified Dulbecco's medium - PBS phosphate buffered saline - TGF- transforming growth factor- - TNF- tumor necrosis factor-     

Modulation of desynchronized sleep through microinjection of α1-adrenergic agonists and antagonists in the dorsal pontine tegmentum of the cat

Noradrenaline is involved in the regulation of the sleep/waking cycle by acting through various receptor types. In previous studies we investigated the role of - and ₂-adrenergic receptors through local microinjections of various drugs into the dorsal pontine tegmentum (DPT) of the cat. This region is known to be crucially involved in desynchronized sleep execution. In this study we examined the role of ₁-adrenergic receptors. The ₁-agonist methoxamine and the ₁antagonist prazosin were injected into the DPT of freely moving, unaesthetized cats. We found that methoxamine notably reduced desynchronized sleep, and that this effect was both dose-dependent and site-specific. These effects were prevented by the subsequent injection of prazosin. On the other hand, the injection into the DPT of prazosin alone produced scarce or inconsistent effects on the sleep/waking cycle.     

Action of prostaglandin F2α on the course of pregnancy and plasma 17β-estradiol concentration in mice

The effect of prostaglandin F₂ (2 mg/kg at each stage of development) on the preimplantation development of mice and on their plasma 17-estradiol concentration was investigated. Prostaglandin F₂ inhibited mitotic division in the embryo and reduced the percentage of embryos shedding the zona pellucida. Meanwhile the 17-estradiol concentration in the peripheral blood plasma fell. Under physiological conditions there was a significant increase in the 17-estradiol concentration at the blastocyst stage after shedding of the zona pellucida.Department of Histology and Embryology, Pediatric Faculty, N. I. Pirogov Second Moscow Medical Institute. Laboratory of Endocrinology, Moscow University. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 88, No. 10, pp. 468–470, October, 1979.