mone (LH). The increase in rats is preceded by increases in ovarian levels of cyclic AMP and progesterone. Systemic administration of indomethacin prevented the increase of ovarian prostaglandin F and blocked ovulation in rabbits and rats. Intrafollicular injection of indomethacin, in rabbits, at dosages which were ineffective when given via systemic injection, blocked the elevation of follicul...

1. Lung resistance was measured by the interruptor method in fifteen patients during infusion of prostaglandin E2 or FZa, for termination of pregnancy. 2. Small but significant reversible elevation in lung resistance occurred in patients receiving both prostaglandins; this was an unexpected finding in the case of prostaglandin E2. 3. The changes described were not harmful in normal subjects, bu...

Prostaglandins have been shown to play a role in carcinogenesis and the progression of many cancers, including prostate cancer. We have recently discovered that the biologically active form of vitamin D, 1,25(OH)2D or calcitriol, regulates multiple genes involved in the prostaglandin pathway. These effects include decreasing prostaglandin synthesis, increasing prostaglandin catabolism, and inhi...

1. An Amberlite XAD-2 column in a heated (37 degrees C) jacket was incorporated in between two banks of bioassay organs superfused with Krebs bicarbonate solution in cascade. The column removed prostaglandins, E1, E2 and F2alpha and also rabbit aorta contracting substance (RCS) and possibly slow reacting substance of anaphylaxis (SRS-A). 2. The column gave free passage to histamine in concentra...

The mechanism of the antifertility effect of the IUD has not been clearly elucidated. Recent experimental results suggest that prostaglandins released by such a device could inhibit implantation (Chaudhuri, 1971; Saksena, Lau & & Castracane, 1974), either by expelling the blastocyst through uterine contractions or by exerting a luteolytic effect. This hypothesis has been tested by administering...

The electrophilic eicosanoids prostaglandins A(1) or A(2) impaired p53-dependent transcription of endogenous genes and exogenous p53-luciferase reporter plasmids in RKO and HCT 116 colon cancer cells. Cellular accumulation of genetically wild-type, but transcriptionally silent p53 varied as a function of exposure time and concentration of prostaglandins A(1) and A(2). Prostaglandins A(1) and A(...

During the last 25 years prostaglandins and, more recently, leukotrienes have commanded increasing interest in the field of medical research. The identification of these substances as potent local hormones which contribute to many physiological and pathological processes has made them the target for potential new therapies. An understanding of the origin of prostaglandins and leukotrienes has l...

The expression of Ia antigen by various murine and human macrophage populations and the ability of prostaglandins of the E series to regulate Ia antigen expression were explored. Monocytes and macrophages from human and murine populations demonstrated a dichotomy in the expression of Ia antigen. Both human monocytes and macrophages expressed elevated levels of Ia antigen compared to their murin...

Recent reports [ 1,2] indicated the presence of seven metabolites of prostaglandin Ez (PGE,) and five metabolites of prostaglandin Fzor (PGFZLY) in the urine of rats after intravenous injection with radioactive prostaglandins. These results suggested that PGE, and PGF2, are converted into three groups of metabolites via three separate pathways which involve oxidation of the hydroxyl group at C-...

Concentrations of prostaglandins E, F, and 6-keto-prostaglandin F1 alpha were estimated in central venous blood and amniotic fluid in 21 women with eclampsia and 16 healthy pregnant controls. Central venous blood concentrations of 6-keto-prostaglandin F1 alpha and prostaglandin E were significantly lower in patients than controls before delivery and remained reduced for at least 48 hours after ...