Prostaglandins and Semen
Murray D. Mitchell in Eicosanoids in Reproduction, 2020
Prostaglandins (PGs) are undoubtedly involved in several aspects of male reproductive physiology, but the uniquely high concentrations in human semen are of particular interest since we are now closer to an explanation of their function. Despite the early work of von Euler, who proposed the prostate as the source of PG in human semen, the evidence is now clear that the seminal vesicles are the main source of PG. Apart from the involvement of PGs in sperm transport from the upper part of the reproductive tract (which would involve PG synthesis in the vasa and the epididymides), there is no evidence to suggest that PGs are involved in the ejaculatory process. The possibility that low testosterone levels could reduce both PGs and fertility cannot be dismissed, as testosterone has a very marked effect on PG secretion in hypogonadal men, and a beneficial effect on sperm motility (presumably indirect, via stimulation of accessory glands) has been reported.
Eicosanoids and the Uterine Cervix
Murray D. Mitchell in Eicosanoids in Reproduction, 2020
The eicosanoids are only part of a complex web of substances that can modify the cervix structure. A web is highly organized and made of chains of events; thus, it would be inappropriate and quite meaningless to consider the eicosanoids and the cervix alone as they can be controlled by and have a controlling action on other parts of the cervix chain. In vivo investigations on the capacity of the uterine cervix to synthesize eicosanoids are confined inevitably to animals. Prostaglandin binding sites in the human cervix are enhanced by estrogen priming, but administration of progesterone following estrogen priming resulted in a down-regulation of progesterone binding sites to negligible levels. Dispersed tissue studies on the collagenous and muscle components of the cervix are required to elucidate their separate biochemical responsiveness to eicosanoids, steroids, relaxin, and oxytocin as well as their ability to synthesize the ground substances.
Eicosanoids in Human Pregnancy and Parturition
Murray D. Mitchell in Eicosanoids in Reproduction, 2020
The involvement of eicosanoids, prostanoids in particular, in human pregnancy and parturition has been studied extensively. The capacity of the human placenta for inactivation of prostaglandins (PGs), for example, suffices to catabolize ten times more PG per minute than needs to be administered intravenously for the induction of labor. The doses of PG synthesis inhibitors that have been used in uncontrolled studies have varied considerably. Gastrointestinal irritation is common with the use of PG synthesis inhibitors, and it can occur irrespective of the route of administration. All intrauterine tissues in late pregnancy are capable of converting free arachidonic acid to PG endoperoxides through the action of prostaglandin endoperoxide synthase, also known as cyclooxygenase. Autopsy and cardiac catheterization data from infants who presented with congestive heart failure at or after birth have suggested that severe constriction of the ductus may also occur before birth in association with the inhibition of PG synthesis.
Normal Phase High Performance Liquid Chromatography of Some Prostaglandin B
Published in Journal of Liquid Chromatography, 1989
William Feely, Herman Shmukler, Robert Dorman
15-Keto-13, 14-trans-prostaglandin B1 methyl ester, 13,14-trans-prostaglandin B1 methyl ester, 13,14-cis-prostaglandin B1 methyl ester, 13,14-dihydro-prostaglandin B1 methyl ester and 13,14-dehydro-prostaglandin B1 are organic intermediates used in the synthesis of prostaglandin Bx, a polymeric derivative of 15-keto-prostaglandin B1 methyl ester. PGBx has been shown to protect laboratory animals against cardiogenic shock, cerebral ischemia and hypoxia. A normal phase, high performance liquid chromatographic analysis is presented which permits the identification and quantitation of these PGB1 intermediates.
Bovine iris-sphincter muscle lacks FP receptor binding sites
Published in Ocular Immunology and Inflammation, 1999
P. Bhattacherjee, B.S. Williams, Partha Mukhopadhyay, C.A. Paterson
PURPOSE: To determine the affinity, density, and specificity of the binding sites of tritium-labeled prostaglandin F 2a in membrane preparations of bovine iris-sphincter muscle and corpus luteum. METHODS: Membrane preparations were incubated with 0.312-40.0 nM 3 H-prostaglandin F 2a in saturation experiments, or 8 nM 2a H-prostaglandin F 2a in competition studies, in the presence or absence of varying concentrations of unlabeled prostaglandin F 2a or other prostaglandin receptor agonists. The affinity (K 2a ) and the density of the binding sites (B 2a ) of 3 H-prostaglandin F 2a in the bovine iris-sphincter muscle were determined by Scatchard analysis. Reverse transcription polymerase chain reaction was performed with bovine iris-sphincter muscle and corpus luteum total RNA and the PCR products were hybridized with specific 32 P-labeled probe for further confirmation of FP receptor expression. RESULTS : Specific binding sites of 3 H-prostaglandin F 2a in the membranes of bovine iris-sphincter muscle are saturable with an affinity of 9.5 nM and a density of 596 fmoles/mg of protein. Prostaglandin E 2a , 17-phenyl trinor prostaglandin E 2a , and GR63799 (EP, EP 2a , and EP 2a receptor agonists, respectively) inhibited 3 H-prostaglandin F 2a binding with an IC 2a of 0.0048 µM, 0.0038 µM, and 0.044 µM, respectively. Fluprostenol, a specific FP receptor agonist did not inhibit 3 H-prostaglandin F 2a binding. In contrast, prostaglandin F 2a and fluprostenol effectively inhibited 3 H-prostaglandin F 2a binding in the bovine corpus luteum with an IC 2a of 0.031 µM and 0.037 µM, respectively. CONCLUSIONS: Our results demonstrate that in the bovine iris-sphincter muscle, FP receptors are not expressed and 3 H-prostaglandin F 2a binds to EP 2a and EP 2a receptor sites. RT-PCR results demonstrated that FP receptor mRNA, which is present in bovine corpus luteum, is probably absent in iris-sphincter muscle.
Lack of association between polymorphisms in the prostaglandin F
Published in Ophthalmic Genetics, 2012
Catherine A. McCarty, Richard Berg, Richard Patchett, Russell A. Wilke, James K. Burmester
Purpose: To evaluate the association between variants in the prostaglandin Fα receptor (PTGFR) and solute carrier organic anion transporter family 2A1 (SLCO2A1) genes and intraocular pressure (IOP) response to prostaglandin analogs. Methods: The medical records of subjects with previously diagnosed open angle glaucoma or ocular hypertension were searched for intraocular pressure measurements before and after prescriptions of prostaglandin analogs. Stored DNA samples were genotyped for the following SNPs: rs3753380 (promoter region) and rs3766355 (intronic region) of the prostaglandin F2α receptor gene, and rs34550074 (Ala396Thr) of SLCO2A1. The mean change in IOP by genotype was measured. Results: Prostaglandin analogs were prescribed to 267 subjects; 242 (204 right eyes, 205 left eyes) met the inclusion/exclusion criteria for the current study. There was no significant association between genotype and IOP response to prostaglandin analogs (p = 0.48, p = 0.54, p = 0.90). Conclusion: In summary, we found no indication for an association between SNPs in the prostaglandin F2α receptor gene or SLCO2A1 and IOP response to prostaglandin analogs in a population of European descent.