dinoprost and cicaprost

We have investigated the actions of various prostanoid receptor agonists on an isolated preparation of the ferret cervical vagus using a grease-gap extracellular recording technique. The potency ranking for depolarization was BW245C (5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl) hydantoin; DP-selective, EC50=0.14 microM)>prostaglandin E2 (nonselective EP agonist)>U-46619 (11alpha, 9alpha-epoxymethano-15S-hydroxyprosta-5Z,13E-dienoic acid; TP agonist)>prostaglandin F2alpha (FP receptor agonist). Sulprostone (EP1/EP3-selective), fluprostenol (FP-selective) and cicaprost and iloprost (both IP-selective) had minimal effects. It is likely that DP, EP2/EP4 and TP receptors are present on the vagal fibres of the ferret.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Biguanides; Dinoprost; Dinoprostone; Dose-Response Relationship, Drug; Electrophysiology; Epoprostenol; Ferrets; Hydantoins; Iloprost; In Vitro Techniques; Male; Prostaglandins; Prostaglandins F, Synthetic; Serotonin; Vagus Nerve

1. A variety of prostanoids were examined for their ability to alter the periarterial nerve stimulation-induced release of noradrenaline (NA) and neuropeptide Y immunoreactive compounds (NPY-ir) from the perfused mesenteric arterial bed of the rat. 2. Periarterial nerve stimulation (16 Hz) increased the overflow of NA, NPY-ir and perfusion pressure. 3. The prostacyclin (PGI2) analogues, carbaPGI2 and cicaprost both produced a concentration-dependent attenuation of the nerve stimulation-induced increase in NA, NPY-ir overflow and perfusion pressure. 4. The prostaglandin (PG) analogue PGE2 attenuated the evoked increase in NPY-ir overflow as well as a modest decrease in NA. 5. PGE1, sulprostone and iloprost attenuated the nerve stimulation-induced increase in NA overflow but not NPY-ir. 6. Neither PGF2alpha nor the thromboxane A2 analogue U46619 altered the evoked increase in NA or NPY-ir overflow. 7. The results support the view that sympathetic co-transmitter release can be differentially modulated by paracrine/autocrine mediators at sympathetic neuroeffector junctions.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Alprostadil; Animals; Dinoprost; Dinoprostone; Electric Stimulation; Epoprostenol; Iloprost; Male; Mesenteric Arteries; Neuropeptide Y; Norepinephrine; Perfusion; Prostaglandins; Radioimmunoassay; Rats; Rats, Sprague-Dawley

In order to characterize prostanoid receptors present in the non-pregnant porcine uterus, the effects of naturally occurring prostaglandins (D2, E2, F2alpha, I2) and synthetic prostanoid receptor agonists on contractility of the longitudinal and circular muscles were examined in vitro. The potent contractile actions of prostaglandin F2alpha and cloprostenol indicate the presence of excitatory FP receptors in the porcine uterus. The longitudinal muscle was more sensitive to FP receptor agonists than was the circular muscle. Prostaglandin D2 produced an excitatory response in the longitudinal muscle but completely inhibited the spontaneous contraction of the circular muscle. BW-245C (5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl)hydantoin, 1 nM-10 microM, a DP receptor agonist) inhibited the spontaneous contractions of both muscles, but the inhibition was conspicuously stronger in the circular muscle. Prostaglandin I2 caused excitatory and inhibitory responses in the longitudinal and circular muscles, respectively, at relatively high concentrations (10-100 microM). Cicaprost, an IP receptor agonist caused inhibition of the contraction in the circular muscle but contracted the longitudinal muscle. Iloprost, an EP(1)/IP receptor agonist, caused excitatory responses in both muscles at relative high concentrations. Prostaglandin E2 caused excitatory responses at 1-100 nM and inhibitory responses at 100 nM-10 microM in both muscle layers. ONO-DI-004 ((17S)-2,5-ethano-6-oxo-17,20-dimethyl prostaglandin E1, an EP1 receptor agonist) and ONO-AE-248 ((16S)-9-deoxy-9beta-chloro-15-deoxy-16-hyfroxy-17,17-trimethylene-19,20-didehydro prostaglandin F2, an EP3 receptor agonist) contracted the longitudinal muscle but had little effect on the circular muscle. ONO-AE1-259 (11,15-O-dimethyl prostaglandin E2, an EP2 receptor agonist) inhibited the spontaneous contractions of both muscle layers to almost the same degree, but ONO-AE1-329 (16-(3-methoxymethyl)phenyl-omega-tetranor-3,7-dithia prostaglandin E1, an EP4 receptor agonist) did not inhibit the myometrial contraction. The present results indicate that contractile (FP, EP1, EP3) and relaxatory (DP, IP, EP2) prostanoid receptors are present in the non-pregnant porcine uterus. There are marked muscle layer-related differences in the degree of responsiveness of prostanoid receptor agonists, and these differences suggest that there is a heterogeneous distribution of prostanoid receptors in the longitudinal and circular m

Topics: Animals; Cloprostenol; Dinoprost; Dinoprostone; Dose-Response Relationship, Drug; Epoprostenol; Female; Hydantoins; Iloprost; In Vitro Techniques; Muscle Contraction; Myometrium; Prostaglandin D2; Receptors, Prostaglandin; Swine

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Dinoprost; Dinoprostone; Epoprostenol; Histamine; Histamine Release; Immunoglobulin E; Male; Mast Cells; Oxytocics; Peritoneal Cavity; Platelet Aggregation Inhibitors; Prostaglandin D2; Prostaglandins, Synthetic; Rats; Rats, Sprague-Dawley; Receptors, Prostaglandin; Structure-Activity Relationship; Vasoconstrictor Agents

Because a balance between the vasodilator effect of Prostacyclin and the vasoconstrictor effect of Prostaglandin F2 alpha (PGF2 alpha) may be necessary for the regulation of utero-placental-fetal blood flow, a study was designed to assess the influence of a stable prostacyclin analogue, Cicaprost, on the response to Prostaglandin F2 alpha in the perfused human placenta. Cicaprost produced a dose-dependent inhibition of the pressor response of 50 mcg of PGF2 alpha. The decrease in PGF2 alpha-induced pressor response by 0.1 mcg of Cicaprost was not significant, only 6.95 +/- 8.2%. However, 0.5 mcg and 1.0 mcg of Cicaprost significantly attenuated the pressor response of PGF2 alpha by 36.6 +/- 9.5% and 46.8 +/- 8.3%, respectively (MEAN +/- S.E.).

Topics: Blood Pressure; Dinoprost; Dose-Response Relationship, Drug; Epoprostenol; Female; Humans; In Vitro Techniques; Perfusion; Placenta; Pregnancy; Vasoconstrictor Agents