Estrogen regulation of methyl p-hydroxyphenyllactate hydrolysis: correlation with estrogen stimulation of rat uterine growth.

We have recently demonstrated that methyl p-hydroxyphenyllactate (MeHPLA) is the endogenous ligand for nuclear type II binding sites in the rat uterus and other estrogen target and non-target tissues. MeHPLA binds to nuclear type II binding sites with a very high binding affinity (Kd approximately 4-5 nM), blocks uterine growth in vivo, and inhibits MCF-7 human breast cancer cell growth in vitro. Conversely, the free acid (p-hydroxyphenyllactic acid, HPLA) interacts with type II binding sites with a much lower affinity (Kd approximately 200 nM) and does not inhibit estrogen-induced uterine growth in vivo or MCF-7 cell growth in vitro.

Methyl p-hydroxyphenyllactate. An inhibitor of cell growth and proliferation and an endogenous ligand for nuclear type-II binding sites.

We previously described and partially characterized endogenous ligands for nuclear type II sites in normal and malignant tissues. Chromatography of these ligands on Sephadex LH-20 revealed that two peaks with binding activity (alpha and beta) could be resolved. The beta-peak component was present in all normal tissues that we examined, but not in malignant tissues, and it inhibited the growth of MCF-7 human breast cancer cells in vitro.

Bioflavonoid interaction with rat uterine type II binding sites and cell growth inhibition.

Competition analysis with a number of known bioflavonoids demonstrated that these compounds (luteolin, quercetin, pelargonin) compete for [3H]estradiol binding to cytosol and nuclear type II sites in rat uterine preparations. The inhibition of [3H]estradiol binding to type II sites was specific and these bioflavonoids did not interact with the rat uterine estrogen receptor. Since estradiol stimulation of nuclear type II sites in the rat uterus is highly correlated with cellular hypertrophy and hyperplasia, we assessed the effects of these compounds on the growth of MCF-7 human breast cancer cells in culture and on estradiol stimulation of uterine growth in the immature rat.

Artifacts in chromatography: an overview.

A brief overview of the field of analytical artifacts is provided, with examples of solvent impurities, stabilizers, polymer additives, and problems relating to Teflon, glassware, and laboratory contaminants.

Gas chromatographic-mass spectrometric analysis of volatile constituents in saliva.

Present methods for the development of metabolic profiles are limited to the use of headspace techniques and solvent extraction methods. A new method for the development of saliva profiles which provides information complementary to existing analyses has been developed. The results of the developed methodology provide a reliable, reproducible method for metabolic profiling.

Dehydrohalogenation of atmospheric contaminants in the space cabin.

A total of nine chlorinated ethanes and ethenes were circulated over lithium hydroxide in a laboratory scale closed system simulator. System volume and lithium hydroxide temperature were varied from that intended to maximize possible reactions to conditions approximating those of a space cabin environment. Of the nine compounds tested, seven were found to be dehydrohalogenated (viz.

Urinary bivalent sulfur metabolites of phenanthrene excreted by the rat and guinea pig.

After the administration of phenanthrene (50 mg/kg, ip) to young adult male rats and guinea pigs, a series of bivalent sulfur urinary metabolites were isolated and characterized by gas chromatography and gas chromatography-mass spectrometry. Seven methylthio metabolites were isolated from the neutral fraction of hydrolyzed rat urine, whereas only two were detected in guinea pig urine. The major methylthio metabolite excreted by each species was 9-hydroxy-10-methylthio-9, 10-dihydrophenanthrene.

Metabolic profiles of penaied shrimp: dietary lipids and ovarian maturation.

The major impediment to the culture of penaeid shrimp in captivity in the United States has been an inability to obtain ovarian maturation and spawning. Lipid profiles of tissues (gonads, hepatopancreas, and tail muscle) of Penaeus setiferus caught at sea have shown that cholesterol is the dominant sterol and that polyunsaturated fatty acids known to be essential in man comprise a significant portion of the fatty acid fraction. A prioprietary marine ration contains cholesterol, but is devoid of polyunsaturated fatty acids.

2,5-Di-t-amyl-p-benzoquinone: an antioxidant encountered during the analysis of human tissues.

The title compound was found in extracts of several human tissues, including neurological tumors, adult brain and fetal brain. It was also present in adhesive tapes used in the laboratory to label glassware, but not in sufficient quantities to be responsible for contamination of the tissues. No source of contamination was found in the hospital.

Aldehyde condensation products as derivatives for the vapor phase analysis of biogenic amines.

The mass spectra of six tetrahydroisoquinolines and five tryptolines are surveyed. It is concluded that tryptolines are suitable for analysis of tryptamines, after condensation with aldehydes.

11, 15, 19-trihydroxy-9-ketoprost-13-enoic acid and 11, 15, 19-trihydroxy-9-ketoprosta-5, 13-dienoic acid in human seminal fluid.

Two novel prostaglandins (PG) have been found in human seminal fluid which had been frozen immediately after collection. They were characterized by combined gas-liquid chromatography-mass spectrometry of various derivatives as 19-hydroxy prostaglandin E1 (11, 15, 19-trihydroxy-9-ketoprost-13-enoic acid) and 19-hydroxy prostaglandin E2 (11, 15, 19-trihydroxy-9-ketoprosta-5, 13-dienoic acid). They were present in three to five times the quantity of prostaglandins E1 and E2.

Mass spectrometric study of the enzymatic conversion of cholesterol to (22R)-22-hydroxycholesterol, (20R,22R)-20,22-dihydroxycholesterol, and pregnenolone, and of (22R)-22-hydroxycholesterol to the lgycol and pregnenolone in bovine adrenocortical preparations. Mode of oxygen incorporation.

Incubation of cholesterol with a bovine adrenocortical mitochondrial acetone-dried powder preparation yielded (22R)-22-hydroxycholesterol (I), (20R,22R)-20,22-dihydroxycholesterol(II), and pregnenolone (III) which were conclusively identified by combined gas chromatography-mass spectrometry. Incubations with [4-14C]cholesterol yielded I, II, and III with specific activities (determined from partial mass-spectral scans) not significantly different from those of the used substrate or the cholesterol reisolated after the incubation, demonstrating that the isolated compounds arose mostly, if not entirely, from the substrate cholesterol. Incubations in an 18O-enriched atmosphere yielded I, II, and III with 18O at position C-22, C-20 and C-22, and C-20, respectively, providing evidence that the hydroxyl groups of the side chain of I and II and the C-20 oxygen atom of III originated from molecular oxygen.

Prostaglandins in human seminal fluid: two novel compounds.

Human seminal fluid frozen immediately after ejaculation contains two novel prostaglandins. These are present in larger quantities than the previously reported prostaglandins. They are characterized by gas chromatography and mass spectrometry as 19-hydroxyprostaglandins E1 and E2.