15-hydroxy-11-alpha-9-alpha-(epoxymethano)prosta-5-13-dienoic-acid and butaprost

The cyclooxygenase-prostanoid pathway regulates myometrial contractility through activation of prostanoid receptors on uterine smooth muscles. However, the possible expression of prostanoid receptors on autonomic nerves cannot be excluded completely. The aim of the present study was to clarify the presence of neural prostanoid receptors on adrenergic nerves in the porcine uterine longitudinal muscle. In [(3)H]-noradrenaline-loaded longitudinal muscle strips of porcine uterus, electrical field stimulation (EFS) evoked [(3)H]-noradrenaline release in a stimulation frequency-dependent manner. The EFS-evoked release was completely abolished in Ca(2+)-free (EGTA, 1mM) incubation medium and by tetrodotoxin or omega-conotoxin GVIA, suggesting that [(3)H]-noradrenaline was released from neural components. The EFS-evoked [(3)H]-noradrenaline release was significantly enhanced by treatment with indomethacin. In the presence of indomethacin, PGE(2) and PGF(2alpha), but not PGD(2), inhibited the EFS-evoked [(3)H]-noradrenaline release. Of synthetic prostanoid receptor agonists examined, both U46619 (TP) and sulprostone (EP(1)/EP(3)) decreased the EFS-evoked [(3)H]-noradrenaline release in a concentration-dependent manner, while fluprostenol (FP), BW245C (DP) and butaprost (EP(2)) were almost ineffective. SQ29548 (TP receptor antagonist) blocked the effect of U46619, but SC19220 (EP(1) receptor antagonist) did not change the inhibition by sulprostone or PGE(2). Double immunofluorescence staining using protein gene product 9.5, tyrosine hydroxylase, EP(3) receptor and TP receptor antibodies suggested the localization of EP(3) or TP receptors on adrenergic nerves in the porcine uterus. These results indicated that neural EP(3) and TP receptors are present on adrenergic nerves of the porcine uterine longitudinal muscle. Endogenous prostanoid produced by cyclooxygenase can regulate noradrenaline release in an inhibitory manner through activation of these neural prostanoid receptors.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Alprostadil; Animals; Dinoprost; Dinoprostone; Electric Stimulation; Female; In Vitro Techniques; Microscopy, Confocal; Microscopy, Fluorescence; Myometrium; Neurons; Norepinephrine; Prostaglandin D2; Prostaglandins; Prostaglandins F, Synthetic; Receptors, Androgen; Receptors, Prostaglandin; Swine

1. The prostanoid receptor(s) on human airways smooth muscle (HASM) cells that mediates the inhibitory effect of PGE(2) on interleukin (IL)-1 beta-induced granulocyte/macrophage colony-stimulating factor (GM-CSF) release has been classified. 2. IL-1 beta evoked the release of GM-CSF from HASM cells, which was suppressed by PGE(2), 16,16-dimethyl PGE(2) (nonselective), misoprostol (EP(2)/EP(3)-selective), ONO-AE1-259 and butaprost (both EP(2)-selective) with pIC(50) values of 8.61, 7.13, 5.64, 8.79 and 5.43, respectively. EP-receptor agonists that have selectivity for the EP(1)-(17-phenyl-omega-trinor PGE(2)) and EP(3)-receptor (sulprostone) subtypes as well as cicaprost (IP-selective), PGD(2), PGF(2 alpha) and U-46619 (TP-selective) were poorly active or inactive at concentrations up to 10 microM. 3. AH 6809, a drug that can be used to selectively block EP(2)-receptors in HASM cells, antagonised the inhibitory effect of PGE(2), 16,16-dimethyl PGE(2) and ONO-AE1-259 with apparent pA(2) values of 5.85, 6.09 and 6.1 respectively. In contrast, the EP(4)-receptor antagonists, AH 23848B and L-161,982, failed to displace to the right the concentration-response curves that described the inhibition of GM-CSF release evoked by PGE(2) and ONO-AE1-259. 4. Inhibition of GM-CSF release by PGE(2) and 8-Br-cAMP was abolished in cells infected with an adenovirus vector encoding an inhibitor protein of cAMP-dependent protein kinase (PKA) but not by H-89, a purported small molecule inhibitor of PKA. 5. We conclude that prostanoid receptors of the EP(2)-subtype mediate the inhibitory effect of PGE(2) on GM-CSF release from HASM cells by recruiting a PKA-dependent pathway. In addition, the data illustrate that caution should be exercised when using H-89 in studies designed to assess the role of PKA in biological processes.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; 8-Bromo Cyclic Adenosine Monophosphate; Adenoviridae; Adolescent; Adult; Aged; Alprostadil; Cell Survival; Cyclic AMP-Dependent Protein Kinases; Dinoprostone; Enzyme Inhibitors; Female; Gene Expression; Genetic Vectors; Granulocyte Colony-Stimulating Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Indomethacin; Interleukin-1; Isoquinolines; Male; Middle Aged; Misoprostol; Myocytes, Smooth Muscle; Prostaglandins E, Synthetic; Protein Isoforms; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP2 Subtype; Receptors, Prostaglandin E, EP4 Subtype; Signal Transduction; Sulfonamides; Trachea; Xanthones

1. Since the role of prostanoid receptors in intestinal peristalsis is largely unknown, the peristaltic motor effects of some prostaglandin (DP, EP, IP), thromboxane (TP) and leukotriene (LT) receptor agonists and antagonists were investigated. 2. Propulsive peristalsis in fluid-perfused segments from the guinea-pig small intestine was triggered by a rise of the intraluminal pressure and recorded via the intraluminal pressure changes associated with the peristaltic waves. Alterations of distension sensitivity were deduced from alterations of the peristaltic pressure threshold and modifications of peristaltic performance were reflected by modifications of the amplitude, maximal acceleration and residual baseline pressure of the peristaltic waves. 3. Four categories of peristaltic motor effects became apparent: a decrease in distension sensitivity and peristaltic performance as induced by the EP1/EP3 receptor agonist sulprostone and the TP receptor agonist U-46619 (1-1000 nM); a decrease in distension sensitivity without a major change in peristaltic performance as induced by PGD(2) (3-300 nM) and LTD(4) (10-100 nM); a decrease in peristaltic performance without a major change in distension sensitivity as induced by PGE(1), PGE(2) (1-1000 nM) and the EP1/IP receptor agonist iloprost (1-100 nM); and a decrease in peristaltic performance associated with an increase in distension sensitivity as induced by the EP2 receptor agonist butaprost (1-1000 nM). The DP receptor agonist BW-245 C (1-1000 nM) was without effect. 4. The peristaltic motor action of sulprostone remained unchanged by the EP1 receptor antagonist SC-51089 (1 micro M) and the DP/EP1/EP2 receptor antagonist AH-6809 (30 micro M), whereas that of U-46619 and LTD(4) was prevented by the TP receptor antagonist SQ-29548 (10 micro M) and the cysteinyl-leukotriene(1) (cysLT(1)) receptor antagonist tomelukast (10 micro M), respectively. 5. These observations and their pharmacological analysis indicate that activation of EP2, EP3, IP, TP and cysLT(1) receptors, but not DP receptors, modulate intestinal peristalsis in a receptor-selective manner, whereas activation of EP1 seems to be without influence on propulsive peristalsis. In a wider perspective it appears as if the effect of prostanoid receptor agonists to induce diarrhoea is due to their prosecretory but not peristaltic motor action.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Alprostadil; Animals; Bridged Bicyclo Compounds, Heterocyclic; Dinoprostone; Dose-Response Relationship, Drug; Fatty Acids, Unsaturated; Female; Guinea Pigs; Hydantoins; Hydrazines; Iloprost; In Vitro Techniques; Intestine, Small; Leukotriene Antagonists; Leukotriene D4; Male; Oxazepines; Peristalsis; Prostaglandin D2; Prostaglandins A; Receptors, Leukotriene; Receptors, Prostaglandin; Xanthenes; Xanthones; Yohimbine

The aim of this study was to compare the effect of two known spasmogens, oxytocin and the stable thromboxane receptor mimetic, U46619, on human myometrium treated with the prostaglandin E receptor (EP2) agonist, butaprost (selective for the EP2 receptor). Strips of myometrium from pregnant and non-pregnant donors were set up in a superfusion apparatus. Butaprost was administered as a bolus dose and via infusion. During the infusion of 10(-6) M butaprost, spasmogens were administered as bolus doses. Butaprost caused dose-related inhibition of myometrial activity when administered as a bolus dose (3-100 nmol) and concentration-dependent inhibition during infusion studies (10(-8)-10(-5 )M). Butaprost (10(-6 )M) attenuated the response to U46619 (0.l-10 nmol) in pregnant myometrium, but this difference was not statistically significant. Responses of pregnant myometrium to oxytocin (0.01-0.1 nmol) were significantly attenuated (P<0.05) in the presence of butaprost (10(-6)M). Butaprost physiologically antagonised the oxytocin response, possibly by increasing intracellular cAMP levels. This antagonism was much more marked than that seen with butaprost and U46619. It is unclear why these two types of antagonism differ and this effect is currently being investigated further using other prostanoid and non-prostanoid agents.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Alprostadil; Analysis of Variance; Depression, Chemical; Dose-Response Relationship, Drug; Female; Humans; In Vitro Techniques; Myometrium; Oxytocin; Parasympatholytics; Pregnancy; Receptors, Prostaglandin E; Tocolytic Agents; Uterine Contraction