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1.
The effects of lanthanum(La) on contractions induced by prostaglandin F2α(PGF2α) or isotonic K+ were investigated in the isolated stomach muscle of guinea-pig.Low concentrations of La(0.1–1 μM) inhibited the contraction to PGF2α 1 μM in a dose-dependent manner, without affecting the tonic contraction to isotonic K+.0.1 and 1 μM La shifted the dose-response curve for PGF2α(0.001 – 1 μM) to the right and reduced the maximum response.The IC50 of La against PGF2α and K+ were 0.6 μM and 30 μM, respectively.These results support the suggestion that PGF2α -induced contraction in the stomach muscle depends mainly on the intracellular release of sequestered Ca, which would be depleted or immobilized by La. 相似文献
2.
Ray V. Haning Jr. Leslie Choi Amber J. Kiggens Donna L. Kuzma John W. Summerville 《Prostaglandins & other lipid mediators》1982,23(1):29-40
Explants from term human placentas were maintained in culture with daily changes of medium. Daily output of PGF2α and PGFM1 decreased during the course of the incubation. Addition of 4 μg/ml DHEAS or 67 μg/ml LDL cholesterol had no effect on output of PGF2α or PGFM. Addition of 1.6, 3.2, or 6.4 μg/ml of LHRH to the culture plates had no effect on output of PGFM or PGF2α, but LHRH increased hCG output. Dibutyryl cAMP (1mM, 2mM, and 4mM) increased output of PGF2α, PGFM, and hCG. Aromatase inhibitor decreased hCG output, but it was without effect on output of PGF2α, or PGFM. Significant correlations were demonstrated between progesterone, PGFM, PGF2α, and hCG, suggesting that PGF2α originates in the syncytiotrophoblast cell. The ability of LHRH to stimulate output of hCG but not PGF2α while dbcAMP stimulated both suggests that either PGF2α and hCG arise in different cells or that LHRH does not act through cAMP. 相似文献
3.
Pregnant hamsters were administered (SC) prostaglandin or vehicle on the morning of the 4th day of pregnancy. Serum progesterone was significantly depressed (p<.01) at 0.5, 2, and 6 hours after treatment with 100 μg PGF2α. Serum progesterone levels were unchanged 2 hours and 6 hours after treatment with 100 μg PGF2β and 2 hours after treatment with 1 mg PGF2β. Progesterone levels were depressed to less than 1 ng/ml 6 hours after treatment with 1 mg PGF2β. The specific uptake of 3H-PGF2α in whole hamster corpora lutea was significantly depressed 2 hours and 6 hours following 100 μg PGF2α treatment. A 15% depression in specific uptake occurred 0.5 hour post-treatment. Treatment with 100 μg PGF2β resulted in no change. Administration of 1 mg PGF2β resulted in depressed 3H-PGF2α uptake at both 2 and 6 hours post-treatment.Prostacyclin (PGI2) treatment resulted in no change in either 3H-PGF2α specific uptake or serum progesterone 2 hours after 100 μg treatment SC. These parameters were both reduced approximately 30% 6 hours post-treatment. Treatment with 6-keto-PGF1α resulted in a complete lack of measurable 3H-PGF2α uptake and serum progesterone levels less than 1 ng/ml at both 2 and 6 hours after treatment with 1 mg SC. 相似文献
4.
Effects of PGD2 and PGF2α on longitudinal and circular muscles of guinea-pig isolated proximal colon
The mechanical effects of PGD2 and PGF2α on longitudinal and circular muscles of the guinea-pig isolated proximal colon were investigated. PGD2 and PGF2α (1 nM – 10 μM) produced a dose-dependent contraction in longitudinal and circular muscles. The contractile action of PGD2 was more potent than that of PGF2α in circular muscle and was less potent in longitudinal muscle.Contractions induced by PGD2 or PGF2α(1 μM) were unaffected by atropine (1 μM) in both muscles, but tetrodotoxin (1 μM) slightly inhibited these contractions in longitudinal muscle.The results suggest that in longitudinal muscle PGD2 and PGF2α have largely a direct action on the muscle cells and a partial neuronal action on the non-cholinergic intrinsic nerves, whereas in circular muscle these PGs have only a direct action on the muscle cells. 相似文献
5.
Prostaglandin F2α (PGF2α) was measured by immunoassay in plasma and milk of four cows (six experiments). After 30 mg PGF2α im, plasma PGF2α peaked at 15 minutes (2.4 ± 0.7 ng/ml) and declined toward basal values by 3 hours; maximum milk PGF2α (0.91 ± 0.12 ng/ml) occurred at 1 hour. The average excretion rate in milk was 2.9 μg/day 0.9 μg (0.003%) of which was due to the 30 mg PGF2α injected. In six non-pregnant control cows, daily changes of milk PGF2α and progesterone were not consistently related. 相似文献
6.
Shiro Ohki Yoshimasa Nishigaki Katsuhiro Imaki Masayasu Kurono Fumio Hirata Toshio Hanyu Nobuhiko Nakazawa 《Prostaglandins & other lipid mediators》1976,12(2):181-186
Radioimmunoassay technique for measuring 5α,7α-dihydroxy-11-keto-tetranorprosta-1,16-dioic acid, the main urinary metabolite of PGF1α and PGF2α (PGF2α-MUM), was further improved.It was postulated based on some experimental data that the PGF2α-MUM exists in the urine mostly as dioic acid form, not as δ-lactone formThe daily excretion of PGF2α-MUM in men ranged from 14.43 μg to 36.14 μg and in women from 5.21 μg to 14.25 μg. 相似文献
7.
Effect of prostaglandin F2α on propulsive activity of the isolated segmental colon of the guinea-pig
The effects of prostaglandin F2α (PGF2α) on propulsive activity in segments of isolated colon and on isolated strips of guinea-pig colon were investigated.Using experimental conditions under which spontaneous propulsive activity was negligible, PGF2α (5×10−8×1×10−6M), added to the bathing medium, increased propulsive activity in a concentration dependent manner. This increase of propulsive activity was abolished in the presence of atropine or tetrodotoxin (1×10−7g/ml).The contractions produced by PGF2α(5×10−7 − 1×10−5M) in isolated longitudinal and circular smooth muscle strips of guinea-pig colon were unaffected in the presence of atropine or tetrodotoxin (1×10−7 g/ml).From these results it is concluded that under the conditions employed in this study propulsive activity stimulated by PGF2α may depend on the contractions of both muscle layers and stimulation of the peristalic reflex. 相似文献
8.
Hydrocortisone (10 μg/ml) had no effect on the basal outputs and A23187-stimulated outputs of PGF2α, PGE2 and 6-keto-PGF1α from the Day 15 guinea-pig uterus superfused
. These findings indicate that the high output of PGF2α from the guinea-pig uterus during the last one-third of the oestrous cycle is not modulated by the adrenal glucocorticoid hormones. Progesterone (10 gmg/ml) had no effect on the A23187-induced increases in PG output from the Day 15 guinea-pig uterus. However, oestradiol (10 gmg/ml but not 1 μg/ml) significantly reduced the increases in outputs of PGF2α, PGE2 and 6-keto-PGF1α induced by A23187 from the Day 15 guinea-pig uterus, without affecting basal PG outputs. The increase in uterine tone induced by A23187 in the Day 15 guinea-pig uterus was reduced by 20–50% by oestradiol (10 μg/ml). The addition of oestradiol (10 μg/ml) and progesterone together (10 gmg/ml) produced the same effects on the Day 15 guinea-pig uterus as oestradiol alone. Oestradiol (10 μg/ml) also reduced the A23187-induced increases in PG output from the Day 7 guinea-pig uterus, but did not reduce the increase in uterine tone. Oestradiol (10 gmg/ml) reduced the increases in outputs of PGF2α, PGE2 and 6-keto-PGF1α induced by exogenous arachidonic acid from the Day 7 and Day 15 guinea-pig uterus. Previous studies have shown that oestradiol is not a cyclo-oxygenase inhibitor. The present findings suggest that oestradiol, at a relatively high concentration, may interfere with the access of arachidonic acid to the cyclo-oxygenase enzyme. This action of oestradiol may explain its anti-luteolytic action when administered to guinea-pigs in large doses after Day 9 of the cycle. 相似文献
9.
Dale R. Bergren Jon M. Gustafson Donna L. Myers 《Prostaglandins & other lipid mediators》1984,27(3):391-405
Pulmonary rapidly-adapting-receptors (RARs) are sensory nerve endings whose afferent fibers can be recorded in the vagus nerve. RARs may play a role in reflex bronchoconstriction as seen in anaphylaxis. They can be stimulated by chemical mediators of anaphylaxis, such as prostaglandin F2α (PGF2α). PGF2α aerosol was administered to saline and bovine serum albumin (BSA)-treated guinea pigs while recording the activity of RARs. PGF2α (250 μg/ml) given for 7–13 minutes increased both tracheal pressure and nerve activity over that produced by saline exposure in untreated guinea pigs. PGF2α administered for three minutes (5–100 μg/ml) increased RAR nerve activity in a dose-related manner in the first five minutes of the experiment only in the BSA treated guinea pigs. Since changes in tracheal pressure did not show a significant dose-response relationship, the RARs responding to PGF2α seemed to be stimulated by a direct mechanism. No correlation was shown between tracheal pressure and RAR nerve activity during PGF2α treatment. Whereas, a significant correlation was found between tracheal pressure and RAR nerve activity during histamine aerosol treatment (r=0.985). Histamine aerosol (1 to 1000 μg/ml, 3 min.) increased intratracheal pressure for 3 out of 4 doses. RAR nerve activity increased significantly only at the highest dose. Therefore, a possible direct effect of PGF2α upon RARs exists while the effect of histamine seems dependent upon changes in airway pressure in the guinea pig. 相似文献
10.
The mechanism of stimulatory and inhibitory action of PGF2α on ovarian steroidogenesis both under
and
conditions has been studied in the pseudo-pregnant rabbits. Short term incubation of the ovaries with PGF2α (2.82 × 10−5M) resulted in an increased synthesis of progesterone and 20α-OH P. The addition of PGF2α in the medium and further incubation of the ovaries obtained from rabbits that had been constantly infused with PGF2α (0.5 μg/min.) for two hours resulted in increased synthesis of these progestins. The ratio of progesterone to 20α -OH P was also enhanced under these conditions and thus supported the luteotropic action of small doses of PGF2α under short term incubations. However, as the amount of PGF2α infused was increased to 5 μg/min., the addition of PGF2α under
conditions strikingly decreased the production of these progestins. The ratio of progesterone to 20α -OH P was also decreased and thus was indicative of luteolytic action of higher doses of PGF2α. High doses of PGF2α (5.64 × 10−4M) failed to I cause any significant change in the progestin synthesis under short term incubation. These results thus suggest that the luteotropic and luteolytic action of PGF2α in the luteinized rabbit ovary is dose and time dependent. 相似文献
11.
(1) The chemotactic activities of thromboxane B2 (TxB2, PGE2, PGF2α, the 15-oxo, 15-oxo-13,14-dihydro and 13,14-dihydro metabolites of PGE2, PGF2α, and a metabolite of TxB2 for polymorphonuclear leucocytes (PMN) have been investigated.(2) Thromboxane B2 increased the directional migrationm of rat peritoneal PMN at a concentration of 2.0 μg/ml and of human peripheral neutrophils at a concentration of 0.5 μg/ml.(3) Neither PGE2, PGF2α nor their metabolites showed chemotactic activity for rat peritoneal PMN.(4) PGF2α and 15-oxo-13,14-dihydro-thromboxane B2 showed no chemotactic activity for human peripheral PMN.(5) The possible role of thromboxane B2 in inflammation is discussed. 相似文献
12.
Tsuneharu Sato Toshikuni Jyujo Toshikiyo Iesaka Junko Ishikawa Masao Igarashi 《Prostaglandins & other lipid mediators》1974,5(5):483-490
Ten to 60 minutes following a single i.v. injection of PGE2 (500 μg/rat) into male rats of 30 to 35 days of age FSH concentration in the serum was raised significantly. The rise in FSH was maintained from 10 to 60 minutes after treatment, then at 90 minutes FSH had declined and was not significantly different from that of the control before treatment. Prostaglandin E1, E2 or F2α (670μg/rat) significantly increased the serum prolactin level 10 to 60 minutes after a single i.v. injection in spayed rats primed with estrogen and progesterone. And, rats primed with estrogen and progesterone. And, increases in prolactin in the serum were observed with as little as 2μg of PGE1 or E2, and 20μg of PGF2α. Twenty μg of PGE2, and 200μg of PGE1 or F2α gave the maximum stimulation. These results indicate that release of pituitary hormones is affected by prostaglandins.Prostaglandins (PGs) are widely distributed in mammalian tissues, and they have been reported to have an almost equally wide variety of endocrine and metabolic effects. It was recently postulated that PGs may be involved in the process of ovulation because ovulation was blocked by inhibitors of PG synthesis (1–5). 相似文献
13.
A technique is described whereby elevated temperature and HCG injection yield a high percentage of ovulation in gravid goldfish. Indomethacin (10 μg/g; i.p. injection) completely inhibits ovulation if given within 6 hours following HCG (4 IU/g); the unovulated oocytes develop rapidly into corpora atretica. PGE1, PGE2, and PGF2α (5 μg/g; i.p. injection) induce ovulation in fish treated with indomethacin and HCG; PGE2 was most effective when given 11 hours after HCG. The results suggest that the ovulatory action of prostaglandins following HCG stimulation is at the level of the ovary and that it is restricted to a period between 7 and 12 hours after the gonadotropin injection. 相似文献
14.
The effect of prostaglandin PGF2α on the hCG stimulated and basal progesterone production by human corpora lutea was examined
. hCG (40 i.u./ml) stimulated progesterone formation in corpora lutea of early (days 16–19 of a normal 28 day cycle), mid (days 20–22) and late (days 23–27) luteal phases. This stimulation was inhibited by PGF2α (10 μg/ml) in corpora lutea of mid and late luteal phases. PGF2α alone did not show a consistent effect on basal progesterone production. The inhibition of hCG stimulated progesterone production by PGF2α at times corresponding to luteolysis indicates a role for that prostaglandin in the process of luteolysis in the human corpus luteum. 相似文献
15.
Dwight R. Robinson Howard Smith Mary B. McGuire Lawrence Levine 《Prostaglandins & other lipid mediators》1975,10(1):67-85
The synthesis of prostaglandins by rheumatoid synovial tissue in organ culture was studied utilizing radioimmunoassay, with antisera to PGB1, PGF1α and PGF2α. It was established that PGE2 and PGF2α were the major prostaglandins formed by analyses of culture media with the two antisera to PGF, before and after alkali treatment. Indomethacin at 5 μg/ml suppressed prostaglandin synthesis, usually to <1% of control cultures. Colchicine, 0.1 μg/ml resulted in marked stimulation of prostaglandin synthesis, in some cases over 10 fold. It is suggested, because of the colchicine effect, that the state of the microtubules may regulate the rate of prostaglandin biosynthesis. It is possible that prostaglandin E2 produced by rheumatoid synovia may contribute to the pathogenesis of the inflammatory reaction and lead to destruction of juxta-articular bone in rheumatoid arthritis. 相似文献
16.
Dwight R. Robinson Howard Smith Mary B. McGuire Lawrence Levine 《Prostaglandins & other lipid mediators》1975,10(4):67-85
The synthesis of prostaglandins by rheumatoid synovial tissue in organ culture was studied utilizing radioimmunoassay, with antisera to PGB1, PGF1α and PGF2α. It was established that PGE2 and PGF2α were the major prostaglandins formed by analyses of culture media with the two antisera to PGF, before and after alkali treatment. Indomethacin at 5 μg/ml suppressed prostaglandin synthesis, usually to <1% of control cultures. Colchicine, 0.1 μg/ml resulted in marked stimulation of prostaglandin synthesis, in some cases over 10 fold. It is suggested, because of the colchicine effect, that the state of the microtubules may regulate the rate of prostaglandin biosynthesis. It is possible that prostaglandin E2 produced by rheumatoid synovia may contribute to the pathogenesis of the inflammatory reaction and lead to destruction of juxta-articular bone in rheumatoid arthritis. 相似文献
17.
John W. Wilks 《Prostaglandins & other lipid mediators》1982,24(6):837-842
Dose response relationships for pregnancy termination in hamsters following administration of prostaglandin F2α (PGF2α by three subcutaneous methods were determined in 526 hamsters. The median effective dose (ED50) for PGF2α given as a single subcutaneous injection in 500 μl of saline was 22.2 μg. Administration of the prostaglandin with an Alzet® osmotic minipump (subcutaneous insertion for 24 hours) required 1.35 times more PGF2α (ED50 = 30.0 μg). The least effective method of prenancy termination in the hamster involved administration of PGF2α by a single subcutaneous injection in 20.4 μl of saline (the same volume delivered by the minipump in 24 hours); the ED50 for this method of administration was 41.3 μg of PGF2α. 相似文献
18.
Non-esterified fatty acids (NEFA) can significantly interfere with the radioimmunoassay of PGE and PGF2α using commercially available anti-sera. PGB1 antigen-antibody binding is 50% inhibited by 110 pg of PGB1, 48 ng of PGE1, 3.5 μg of PGF2α, or 9.0 μg linoleic, 14 μg arachidonic, 22 μg δ-linoleic, 40 μg palmitoleic or 45 μg oleic acids. PGF2α antigen-antibody binding is 50% inhibited by 270 pg of PGF2α, 70 ng of PGE1, or 4.2 μg arachidonic, 14 μg δ-linolenic, 22 μg linoleic, 70 μg palmitoleic or 110 μg oleic acids. Physiological levels of NEFA, such as the quantities found in small volumes of plasma, are sufficient to prohibit accurate prostaglandin measurements. Chromatography on small columns of silicic acid proved to be an effective technique for separation of NEFA and prostaglandin from lipid extracts, however, the results of this study suggest that the interference produced by the presence of NEFA in the measurement of prostaglandin from certain physiological fluids may be avoided if the prostaglandins are not extracted prior to radioimmunoassay. 相似文献
19.
The conversion of arachidonic acid to prostaglandins (PG's) and thromboxane B2 (TXB2) was investigated in homogenates from fetal and adult bovine and rabbit lungs. Adult bovine lungs were very active in converting arachidonic acid (100 μg/g tissue) to both PGE2 (10.7 μg/g tissue) and TXB2 (6.2 μ/g tissue). Smaller amounts of PGF2α (0.9 μ/g) and 6-oxoPGF1α were formed. Homogenates from fetal calf lungs during the third trimester of pregnancy were quite active in converting arachidonic acid to PGE2, but formed very little TXB2, PGF2α or 6-oxoPGF1α. Homogenates from rabbit lungs converted arachidonic acid (100 μg/g) mainly to PGE2, both before and after birth. The amount of PGE2 formed increased during gestation to a maximum of about 6 μg/g tissue at 28 days of gestation. It then decreased to a minimum (1.5 μg/g) which was observed 8 days after birth, followed by an increase to about 4 μg/g in older rabbits. 相似文献
20.
J. N. Stellflug T. M. Louis H. D. Hafs B. E. Seguin 《Prostaglandins & other lipid mediators》1975,9(4):609-615
During diestrus in three consecutive estrous cycles, each of six heifers was given (im) 30 mg, 15 mg (twice at 6-hr intervals) and 60 mg prostaglandin F2α (PGF2α) tham salt. Neither the decline in blood progesterone, the increase in blood estradiol, the duration or the peak of the LH surge, the interval to onset of estrus, nor the interval to ovulation was affected significantly by dose of PGF2α. Thus, relative to that after 30 mg PGF2α im, two injections of 15 mg at 6-hr intervals or 60 mg PGF2α did not hasten luteolysis. Thirty mg was an ample im dose of PGF2α to cause luteolysis. Regardless of im dose of PGF2α, blood PGF peaked at about 6.0 ng/ml within 10 minutes and returned to basal values (<1.0 ng/ml) within 90 minutes. In another trial, after a single iv injection of 5 mg PGF2α, blood PGF peaked (25 ng/ml) within 5 minutes and returned to basal values within 15 minutes. During a 30-minute infusion (0.5 mg/minute) of PGF2α, blood PGF plateaued at 29.5 ng/ml with a metabolic clearance rate of 17.0 liters per minute. 相似文献