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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Progesterone-binding proteins from human, rabbit, sheep and guinea pig myometrial cytosol, all induced with oestradiol, as well as from pregnant guinea pig myometrium and plasma were investigated. The physico-chemical properties of the oestradiol-induced binding proteins were very similar in all the species studied. In all, 63 steroids were tested for their ability to compete with tritiated progesterone for the binding sites on these six proteins and their relative affinities were determined. The studies reveal that the ligand specificities of oestrogen-induced myometrial binding proteins from human, rabbit and sheep are rather similar, whereas that from guinea pig myometrium has different binding characteristics. The properties of the binding proteins from pregnant guinea pig uterus and plasma differ substantially from all of the induced proteins. It is clear from the different physico-chemical characteristics and binding specificities that the oestrogen-induced myometrial protein of the guinea pig is not the same as that which appears in the myometrium and plasma during pregnancy. The binding energies of the well bound progestational compounds were of the order of -12 Kcal/mole, half of which stems from the interaction of the steroid nucleus with the protein. The specific interaction of the protein with the two functional groups, the 3-keto-4-ene system and the acetyl sid chain each contributed-3 Kcal/mole. In the case of the rabbit, sheep and human proteins a 17alpha-ethynyl-17beta-hydroxyl function could replace the acetyl side chain. For a large number of steroids reasonable agreement existed between the degree of binding to the rabbit myometrial protein and in vivo biological activity (Clauberg-McPhail test) in the same species. The data suggest that as far asthe binding aspect is concerned, the rabbit is an appropriate model for assessing the biological activity of compounds under development for human application. The in vitro binding system is also a useful tool to assess whether steroids need to be bio-activated before eliciting a biological response.
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PMID:Progesterone-binding proteins: in vitro binding and biological activity of different steroidal ligands. 16 94

The solubility of progesterone was determined in several different bile salt-phospholipid mixtures, and it is concluded that: (1) The solubility in unconjugated bile salts is greater than in the conjugated analogues, and the solubility in deoxycholate solutions is twice that in cholate solutions. (2) Substitution of hydroxyl groups in the 11 and 21 positions of progesterone increases solubility, whilst substitution in the 17-position decreases solubility in bile salt solutions. (3) Progesterone solubility in mixed bile salt solutions is proportional to the mole ratio of the surfactant mixture. (4) Sodium deoxycholate (SDC)-phospholipid sols show no such linear solubilizing properties; a minimum occurring at a mole ratio of SDC to phospholipid of 1 : 4. (5) There is a break in the solubility curve of progesterone in lysophosphatidycholine (LPC)/phosphatidylcholine (PC) mixtures at a mole ratio of 65 : 35 coincident with maximum viscosity. (6) Introduction of SDC into LPC/PC mixtures results in decreased progesterone solubility.
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PMID:The solubilization of progesterone by mixed bile salt-phospholipid sols. 71 19

This study was carried out as a step toward clarifying the hormone responsiveness of mammary tumors in the F1 hybrid mice of the GR/A and SHN strains. Mammary tumors in SHN mice are pregnancy-independent while mammary tumors of GR/A mice are pregnancy-dependent. Females of each strain were mated with males of the other strain to produce F1 hybrids. They were subjected to forced breeding without subsequent lactation. Only animals with palpable mammary tumors during 2nd and 4th pregnancies were used. Mice received sc injections of several hormones, singly or in combination, daily from 1 day after parturition, i.e., .5 mcg of estradiol benzoate (EB) and of 100 mcg human placental lactogen (HPL). The dose of progesterone (P) before parturition was 100 mcg and after parturition 1 mg. A group received grafts of isologous pituitary glands under kidney capsules (3 AP) during Days 12-34 of pregnancy. 1 day after parturition each mouse was given a single ip injection of 50 micro Ci tritiated-thymidine (tritiated-TdR; 5 Cim/mole) along with the last injection of hormones. Animals were killed 2 hours later. Cyclic SHN mice with mammary tumors received tritiated-TdR, after 2 daily injections of hormones, for 3 days, or after 7-8 days of 3AP. The index of DNA synthesis was determined by a liquid scintillation countermeasuring tritiated-TdR incorporated with DNA. Some of the mice were bled 1 day after parturition and plasma prolactin assayed. Hormone responsiveness was similar among GR/A and both F1 hybrids in either normal or neoplastic glands. DNA synthesis of mammary tumors did not respond to any hormone used but normal glands were stimulated by the hormones. EB injection or 3AP did not alter tritiated-TdR incorporation. HPL injection stimulated DNA synthesis of normal glands but not of tumors. P significantly increased the synthesis of both normal and neoplastic mammary glands. EB and HPL injected with P also significantly promoted DNA synthesis of tumors, but did not increase synthesis in normal glands cuased by P. Plasma prolactin levels were significantly increased by EB injection or by 3AP but were not altered by P. In SHN mice DNA synthesis in mammary tumors was not altered by any hormone treatment but synthesis in normal glands was increased by all treatments. Findings suggest that the hormone-responsiveness of pregnancy-dependent mammary tumors in GR/A and its F1 hybrids is different from some other mammary tumors in mice and rats. Progesterone was more important than prolactin or estrogen for tumor growth. Although EB injection was without effect, intact mice were used so some endogenous estrogen may have participated in the effect. While hormone responsiveness of mammary tumors was different between GR/A and SHN mice, the tumors in both hybrids (BR/A with SHN F1 and SHN with GR/A F1) showed responses quite similar to those of tumors of GR/A mice. This suggests the dominance of the GR/A genotype over the SHN genotype for determining the biological characteristics of mammary tumors.
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PMID:Importance of progesterone in DNA synthesis of pregnancy-dependent mammary tumors in mice. 98 72

Serum progesterone was estimated by a competitive protein-binding method in the peripheral venous blood in 12 cases of normal pregnancy at the time of delivery and in maternal venous blood, umbilical venoms, and umbilical arterial blood in another 5 cases. Progesterone concentration in the peripheral blood and in the serous fluid of molar vesicles was measured in 18 cases of hydatidiform mole. The theca lutein cyst fluid from 3 patients with hydatidiform mole was also assayed for progesterone. Umbilical cord venous blood and umbilical arterial blood showed a variable concentration of progesterone with a mean fetal-maternal progesterone ratio of 4.7 plus or minus 0.6 and a mean umbilical vein-artery progesterone ratio of 5.7 plus or minus 0.4. Serum progesterone concentration in hydatidiform mole was from 25.0 to 263.2 ng/ml with a mean plus or minus standard error of 101.7 plus or minus 15.2 ng/ml, while the corresponding mole vesicle fluid progesterone concentration ranged from 260.5 to 1842.0 ng/ml with a mean plus or minus SE of 770.9 plus or minus 87.4 ng/ml. The ratio of progesterone in vesicle fluid and in the serum was 4.0 to 52.8 (mean, 7.6). Progesterone concentrations in the theca lutein cyst fluid from 3 patients with hydatidiform mole were 25,428 ng/ml; 7,635 ng/ml; and 4,686 ng/ml. The high fetal-maternal progesterone ratio and umbilical vein-artery progesterone ratio reflect preferential progesterone transfer to the fetus and utilization by the latter. The finding in hydatidiform mole is due to the absence of the fetus and indicates that the molar trophoblast produced progesterone in significant amounts and that theca lutein cysts have a very high but variable concentration of progesterone in their fluid.
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PMID:Progesterone in molar vesicle fluid and theca lutein cyst fluid. 112 67

The affinity alkylating progesterone analogue 17-(bromoacetoxy)progesterone has been used to label the active site of a microsomal cytochrome P-450 enzyme from neonatal pig testis. The enzyme causes removal of the C20 and C21 side chains from the substrates progesterone and pregnenolone by catalyzing both 17-hydroxylase and C17,20-lyase reactions, which produce the corresponding C19 steroidal precursors of testosterone. The progesterone analogue causes simultaneous inactivation of the two catalytic activities of the enzyme by a first-order kinetic process that obeys saturation kinetics. Progesterone and 17-hydroxyprogesterone each protect the enzyme against inactivation. The progesterone and analogue is a competitive inhibitor of the enzyme with Ki values of 8.4 microM and 7.8 microM for progesterone and 17-hydroxyprogesterone, respectively. The enzyme inactivation and kinetic data are consistent with a theory proposing that the analogue and the two substrates compete for the same active site. The radioactive analogue 17-[( 14C]bromoacetoxy)progesterone causes inactivation of the enzyme with incorporation of 1.5-2.2 mol of the analogue per mole of inactivated enzyme. When this experiment is carried out in the presence of a substrate, then 0.9-1.2 mol of radioactive analogue is incorporated per mole of inactivated enzyme. The data suggest that the analogue can bind to two different sites, one of which is related to the catalytic site. Radiolabeled enzyme samples, from reactions of the 14C-labeled analogue with the enzyme alone or with enzyme in the presence of a substrate, were subjected to amino acid analysis and also to tryptic digestion and peptide mapping.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Affinity alkylation of the active site of C21 steroid side-chain cleavage cytochrome P-450 from neonatal porcine testis: a unique cysteine residue alkylated by 17-(bromoacetoxy)progesterone. 349 7

Immunofluorescent assessment of hormone receptors in melanocytic tumours is quite feasible without loss of diagnostic material, in contrast to the impracticability of quantitative biochemical assays. Using this method, oestrogen receptors were demonstrated in 4/6, and progesterone receptors in 3/5 patients with metastatic melanoma. Receptors were not found in 3 patients with primary cutaneous melanomas of the superficial spreading type. Progesterone receptors were present in the junctional component of a naevus from one healthy person.
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PMID:Immunofluorescent detection of hormone receptors in cutaneous melanocytic tumours. 626 40

Controlled trophoblast invasion is a key process during human placentation and a prerequisite for successful pregnancy. Progesterone is one of the factors to regulate trophoblast invasiveness. Progesterone-induced blocking factor (PIBF) is a progesterone-induced molecule expressed by the trophoblast, and also by tumors. The distribution of PIBF within the first-trimester decidua coincides with sites of trophoblast invasion. Another molecule that has been implicated in the control of trophoblast invasiveness is placental leptin. Leptin inhibits the secretion of progesterone by cytotrophoblast. The aim of this work was to investigate the possible interaction of PIBF and leptins in regulating trophoblast invasion. Paraffin-embedded sections from normal first-trimester placentae, partial moles, complete moles, and choriocarcinomas were reacted with PIBF, leptin, and leptin receptor specific antibodies. PIBF-deficient trophoblast cells were generated using siRNA and leptin receptor was detected on Western blot analysis. The lysates of PIBF-treated cells were used for detecting leptin expression in a protein array. PIBF was expressed in both normal first-trimester villous trophoblast and in partial mole. Compared with this, PIBF expression was markedly decreased in complete mole and absent in choriocarcinoma. Neither leptinR nor leptin were detected in partial mole, whereas both of these molecules were present in complete mole and choriocarcinoma. Leptin receptor expression was upregulated in PIBF-deficient cells, while leptin expression was decreased in PIBF-treated cells. These data suggest that PIBF affects the expression of leptin and its receptor, and that PIBF expression is inversely related to trophoblast invasiveness.
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PMID:Progesterone-induced blocking factor (PIBF) and trophoblast invasiveness. 2163 19