FP receptor; prostaglandin F (PGF) receptor; Endogenous Metabolite

Goat luteal cells undergo necrosis, autophagy, and endoplasmic reticulum prolapse when exposed to dinoprost (prostaglandin F2α; 1 μM) for a full day [1]. Dinoprost (1 μM) raised GRP78 and UPR sensor substantially throughout a 24-hour period.

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The ET-1-induced (10(-8) M) contraction in isolated BTM was inhibited by PGF2alpha (10(-6) M) and fluprostenol (10(-6) M). This effect was blocked by FP receptor antagonists. Carbachol-induced contraction or baseline tension was not affected by PGF2alpha or fluprostenol. In cultured TM cells, ET-1 caused a transient increase in [Ca2+]i that was reduced by PGF2alpha. No reduction occurred in the presence of the FP receptor antagonist Al-8810. Western blot analysis revealed the expression of the FP receptor in native and cultured TM. Conclusions: FP receptor agonists operate by direct interaction with ET-1-induced contractility of TM. This effect is mediated by the FP receptor. Thus, FP receptor agonists may decrease IOP by enhancing aqueous humor outflow through the TM by inhibiting ET-1-dependent mechanisms.[1]

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Corpus luteum (CL) is a transient endocrine tissue that produces progesterone for maintaining pregnancy in mammals. In addition, the regression of CL is necessary for the initiation of the estrous cycle. Extensive research has shown that the prostaglandin F2α (PGF2α) induces the regression of CL in ruminants. However, the mechanisms of endoplasmic reticulum (ER) stress and autophagy in the regression of goat CL induced by PGF2α are still unclear. In this study, ovaries of dioestrus goats and goats that were 3 months pregnant were collected to detect the location of the ER stress-related protein GRP78. The relationship between the different stages of the luteal phase of goat CL during the estrous cycle and changes in the expression of ER stress-related proteins and autophagy-related proteins was confirmed by western blot analysis. The results showed that both ER stress and autophagy were activated in the late luteal phase of the goat CL. To reveal the function of ER stress and autophagy in the CL regression process induced by PGF2α, we used 4-phenyl butyric acid (4-PBA) and chloroquine (CQ) for inhibiting ER stress and autophagy, respectively. Through the apoptotic rate detected by the flow cytometry and the expression of ER stress- and autophagy-related proteins detected by western blotting, we demonstrated that ER stress promoted goat luteal cell apoptosis and autophagy, and that apoptosis can be enhanced by the inhibition of autophagy. In addition, knockdown of EIF2S1, which blocked the PERK pathway activation, promoted apoptosis by reducing autophagy in goat luteal cells treated with PGF2α. In conclusion, our study indicates that ER stress promotes goat luteal cell apoptosis to regulate the regression of CL and activates autophagy to inhibit the goat luteal cell apoptosis via PERK signaling pathway[2].

Apoptosis analysis [1]
Cell Types: Goat luteal cells
Tested Concentrations: 1 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: Significant apoptosis rate increased (15.62±3.12%). Autophagy detection [1]
Cell Types: goat luteal cells
Tested Concentrations: 1 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: There is extensive overlap between LC3 and LAMP1 in luteal cells, and autophagic lysosomes are formed in goat luteal cells.

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Western Blot Analysis[1]
Cell Types: Goat luteal cells
Tested Concentrations: 1 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: Expression of GRP78 and UPR sensors, including cleaved ATF6, phospho-EIF2S1, EIF2S1, ATF4, phospho-IRE1, autologous Phagocytosis-related intracellular protein LC3-II and pro-apoptotic factor cleaved Caspase3 were Dramatically increased.

Goat ovaries were collected from sexually mature healthy goats and from goats that were pregnant for 3 months in a local abattoir within 10–20 min of slaughter. The duration of pregnancy was determined by the size and morphological characteristics of the fetus. Fresh ovaries stored on ice were taken back to our laboratory within 30 min for subsequent sampling. The complete CL was exfoliated during the estrous cycle from the non-pregnant goats’ ovaries on ice, and each CL was divided into two equal parts. These CL tissues were frozen in liquid nitrogen and stored at −80°C until RNA and protein extraction. Based on the detection of morphological characteristics and the levels of marker genes’ expression, such as STAR, 3βHSD, LH-R, and CYP19A1, in these goat CLs as previously described (Farin et al., 1986), the stages of the luteal phase of the CLs were categorized into five main groups [i.e., early (1–3 day after ovulation), mid1 (4–7 day after ovulation), mid2 (8–12 day after ovulation), mid3 (13–16 day post-ovulation), and late (17–20 post-ovulation)] (Figures 1B,C). For one independent experiment, we exfoliated goat CLs from at least three ovaries in each luteal stage (n = 3 ovaries per stage). All other ovaries fixed in paraformaldehyde (4%) for immunohistochemistry analysis were collected from three dioestrus goats and three pregnant goats.

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Ex Vivo Bovine TM Contractility Measurement: Bovine eyes were obtained fresh from a slaughterhouse. TM strips (2-4 mm long) were carefully dissected. The strips were mounted in an organ bath containing Ringer's solution at 37°C, pH 7.4, gassed with 5% CO₂ in air. They were allowed to equilibrate for at least 1 hour under control conditions. Direct isometric tension measurements were performed using a force-length transducer. To test the effect of Dinoprost (PGF₂α) on ET-1-induced contraction, tissue strips were pre-incubated with Dinoprost (PGF₂α) (10⁻⁶ M) for 20 minutes before ET-1 (10⁻⁹ or 10⁻⁸ M) was applied in the continued presence of the prostaglandin. For experiments with FP receptor antagonists, the tissue was pre-incubated with the antagonist (PGF₂α dimethylamide or PGF₂α dimethylamine, 10⁻⁶ M) for 20 minutes before the addition of Dinoprost (PGF₂α) and subsequently ET-1. Contractions induced by ET-1 were expressed relative to the response obtained with a maximal effective concentration of carbachol (10⁻⁶ M) tested in each strip as an internal control, which was set to 100% force. [1]

Absorption, Distribution and Excretion
Currently studied seminal compounds include prostaglandins (25 mg/ml). /Prostaglandins/ Aside from typically slow and species-dependent isomerization, PGS E and PGS F are fairly stable in the blood, but they are rapidly degraded and inactivated by tissue-binding enzymes; approximately 80-90% or more is destroyed during a single passage through the liver or lungs. /Prostaglandins/ The degree of binding of prostaglandins to plasma proteins appears to have little effect on their metabolic and clearance rates. …Whether prostaglandins are administered in free form or bound to rat plasma albumin, the clearance rate of (3)H remains unchanged. /Prostaglandins/

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Metabolism/Metabolites …Prostaglandin metabolism is rapid… /Prostaglandins/

Interactions
Fenamic acid, phenylbutazone, and aspirin (with weaker effects) can inhibit the contractile response of isolated human bronchial muscle to prostaglandin F2α.

[1]. Endothelin antagonism: effects of FP receptor agonists prostaglandin F2alpha and fluprostenol on trabecular meshwork contractility. Invest Ophthalmol Vis Sci. 2006 Mar;47(3):938-45.

[2]. Prostaglandin F2α Induces Goat Corpus Luteum Regression via Endoplasmic Reticulum Stress and Autophagy. Front Physiol. 2020 Sep 11;11:868.

Prostaglandin F2α is a prostaglandin Fα with the structure prostaglandin-5,13-diene-1-acid, substituted with hydroxyl groups at positions 9, 11, and 15. It is a naturally occurring prostaglandin used for labor induction. It is a metabolite in both humans and mice. It is a prostaglandin Fα and a monocarboxylic acid. It is the conjugate acid of prostaglandin F2α(1-). Dinoprost has been used to treat headaches. Dinoprost has been reported in Homo sapiens, Japanese deer, and other organisms with relevant data. Dinoprost is a synthetic analogue of naturally occurring prostaglandin F2α. Prostaglandin F2α stimulates uterine myometrial activity, relaxes the cervix, inhibits progesterone production, and induces luteal dissolution through direct action on the corpus luteum. (NCI04) Prostaglandin F2α is a naturally occurring prostaglandin that stimulates uterine myometrial activity, relaxes the cervix, inhibits progesterone production, and induces luteal dissolution through direct action on the corpus luteum. Elevated expression of prostaglandin F2α (PGF2) is observed in certain types of cancer. A naturally occurring prostaglandin, it has oxytocin, luteolytic, and abortifacient effects. Due to its vasoconstrictive properties, this compound also has a variety of other biological functions. See also: dinoprost tromethamine (salt form). Mechanism of Action: ...There is no single prostaglandin receptor. ...Multiple responses to prostaglandins have been shown to be calcium-dependent, and alterations in calcium flow have been observed. ...Prostaglandins can both stimulate and inhibit the accumulation of cyclic adenosine monophosphate (cAMP). Prostaglandins: Responses to prostaglandin F2α vary among species, but vasodilation has been observed after injection of PGF2α into the human brachial artery...PGF2α can cause vasoconstriction in the superficial veins of the hand...Parenteral injection of prostaglandin F2α rapidly reduces progesterone secretion and causes corpus luteum degeneration...This effect can interrupt early pregnancy, which depends on corpus luteum rather than placental progesterone. Oxytocin and prostaglandins affect uterine smooth muscle through different mechanisms. The mechanisms of action and effects of these drugs are additive. The potential benefits of combined use are currently being explored. /Prostaglandins/

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Therapeutic Uses
Nonsteroidal abortifacients; oxytocin
…Some doctors prefer to postpone abortion until after 16 weeks of gestation, when the intra-amniotic route can be performed more safely. /Denoprost Tromethamine/
Extra-amniotic route (currently under investigation) requires the placement of an indwelling catheter in the uterus outside the ovary via the vagina. ...Used only for termination of pregnancy between 13 and 15 weeks of gestation... /Denoprost Tromethamine/
Intrauterine administration achieves effective concentrations within the myometrium, requiring the lowest possible dose. Intra-amniotic instillation is performed by inserting a long spinal needle into the amniotic sac via the abdomen. /Denoprost Tromethamine/
For more complete data on the therapeutic uses of prostaglandin F2α (15 in total), please visit the HSDB record page.

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Drug Warnings
Asthmatic patients are particularly sensitive; PGF2α has been shown to cause severe bronchospasm.
Some researchers have noted that prostaglandins may exhibit a narrow dose-response range in producing physiological contractions and causing excessive uterine tone; this potential risk can be avoided by very cautiously increasing the infusion rate gradually. Prostaglandin drugs used for mid-pregnancy abortion…can cause…common but tolerable side effects. However, for very early abortion (menstrual delay of several weeks), success rates have been reported to be low, and the required doses can cause serious side effects. Prostaglandins are contraindicated in acute pelvic inflammatory disease. Caution should be exercised in patients with a history of hypertension, asthma, glaucoma, epilepsy, or cardiovascular disease. For more complete data on drug warnings for prostaglandin F2α (11 in total), please visit the HSDB records page.

C20H34O5

354.4810

354.24

C, 67.77; H, 9.67; O, 22.57

551-11-1

Dinoprost tromethamine salt;38562-01-5;(5R)-Dinoprost;4510-16-1;Dinoprost-d4;34210-11-2;Dinoprost-d9

5280363

White to light brown <25°C powder,>35°C liquid

1.2±0.1 g/cm3

531.0±50.0 °C at 760 mmHg

120°C

289.0±26.6 °C

0.0±3.2 mmHg at 25°C

1.569

2.14

4

5

12

25

432

5

O([H])[C@@]1([H])C([H])([H])[C@]([H])([C@]([H])(/C(/[H])=C(\[H])/[C@]([H])(C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H])O[H])[C@@]1([H])C([H])([H])/C(/[H])=C(/[H])\C([H])([H])C([H])([H])C([H])([H])C(=O)O[H])O[H]

PXGPLTODNUVGFL-YNNPMVKQSA-N

InChI=1S/C20H34O5/c1-2-3-6-9-15(21)12-13-17-16(18(22)14-19(17)23)10-7-4-5-8-11-20(24)25/h4,7,12-13,15-19,21-23H,2-3,5-6,8-11,14H2,1H3,(H,24,25)/b7-4-,13-12+/t15-,16+,17+,18-,19+/m0/s1

(Z)-7-((1R,2R,3R,5S)-3,5-dihydroxy-2-((S,E)-3-hydroxyoct-1-en-1-yl)cyclopentyl)hept-5-enoic acid

Cerviprost; HSDB 3315; Panacelan; Prostaglandin F2a; Prostaglandin F2alpha; Prostaglandin F2a; PGF2alpha; amoglandin; Enzaprost; Protamodin;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~100 mg/mL (~282.10 mM)
DMSO : ~100 mg/mL (~282.10 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.05 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.05 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)