AIM: TO explore the ability of recombinant toxin luteinizinghormone releasing hormone-Pseudomonas aeruginosaexotoxin 40 (LHRH-PE40) and LHRH binding to LHRH receptor(LHRHR) on the membrane surface of human liver cance...AIM: TO explore the ability of recombinant toxin luteinizinghormone releasing hormone-Pseudomonas aeruginosaexotoxin 40 (LHRH-PE40) and LHRH binding to LHRH receptor(LHRHR) on the membrane surface of human liver cancerHEPG cells.METHODS: LHRH was labeled by using 12sI with enzymaticreaction. The affinity and receptor volume of LHP, H-PE40and LHRH binding to LHRHR on the membrane surface ofhuman liver cancer cells were measured with radioligandreceptor assay.RESULTS: The specific activity of LHRH labeled with 12sIwas 2.7x 104 kBq/l^L, and its radiochemical purity reachedto 99.2-99.7%. The binding of 12sI to LHRH was maximalfor 240 min in the warm cultivation, and this binding wasstabilized. The inhibiting rates of ~2SI-LHRH and LHRH onthe proliferation of human liver cancer HEPG cells werenot significantly different. On the basis of the saturationcurve of ~2SI-LHRH binding to the membrane LHRHR of HEPGcells, ~2SI-LHRH of lx10s cpm was selected for radioligandreceptor assay. The affinity constants (Kd) of LHRH-PE40and LHRH binding to the membrane LHRHR of HEPG cellswere 0.43~0.12 nmol/L and 4.86~ 1.47 nmol/L, respectively,and their receptor volumes were 0.37~0.15 l^mol/g and0.42=I=0.13 l^mol/g, respectively. The binding of LHRH-PE40to the membrane protein of normal liver cells was notobserved.CONCLUSION: The recombinant toxin LHRH-PE40 binding tothe membrane surface of LHRHR of human liver cancer HEPGcells was very strong, while the specific binding of it to normalliver cells was not observed. The results provide an importantexperimental basis for the clinical application of LHRH-PE.展开更多
The effects of two intraperitoneal injections of human chorionic gonadotropin (HCG) or [ D-ALA6, pro9- N- ethylamide]-luteinizing hormone releasing hormone analogue (LHRH-A), respectively, and the combined effect of L...The effects of two intraperitoneal injections of human chorionic gonadotropin (HCG) or [ D-ALA6, pro9- N- ethylamide]-luteinizing hormone releasing hormone analogue (LHRH-A), respectively, and the combined effect of LHRH-A with pimozide (PIM), a dopamine antagonist, on ovulation in female mud skipper were investigated. A high rate of ovulation (83.3%)was observed after injection with HCG(30 I. U./g). Injection of LHRH-A at a total dosage of 2μg/g was 100% effective in inducing ovulation. No ovulations occurred in the group receiving a low dosage of LHRH-A (0.02μg/g). Injection of LHRH-A(0.2μg/g)with PIM (10 or 20 μg/g)induced greater ovulatory response than injection with LHRH-A (0.2μg/g)alone. PIM at total dosages of 0.2μg/g or 2μg/g did not enhance the potency of LHRH-A to stimulate ovulation.展开更多
Using fluoromctric technique wc tcstcd ED50 ofhistaminc release by LHRH antagonists.There wcrc 9 LHRH antagonists synthesized by us and tested by this method. The range of ED50 is from 0.65±0.08/μg / ml, to 36.8...Using fluoromctric technique wc tcstcd ED50 ofhistaminc release by LHRH antagonists.There wcrc 9 LHRH antagonists synthesized by us and tested by this method. The range of ED50 is from 0.65±0.08/μg / ml, to 36.8±2.8 /μg / ml. We selected a LHRH展开更多
LHRH self-priming effect is simply defmed as an enhancement of LH response to LHRH, i. e., a second challenge with LHRH elicits more LH secretion as compared to the first challenge. The present study is to observe whe...LHRH self-priming effect is simply defmed as an enhancement of LH response to LHRH, i. e., a second challenge with LHRH elicits more LH secretion as compared to the first challenge. The present study is to observe whether this phenomenon exists in perfused anterior pituitary (AP) cells of adult male rat. Dispersed AP cells of adult展开更多
基金Supported by the Key Programs of National Science and Technology,No.96-901-05-101
文摘AIM: TO explore the ability of recombinant toxin luteinizinghormone releasing hormone-Pseudomonas aeruginosaexotoxin 40 (LHRH-PE40) and LHRH binding to LHRH receptor(LHRHR) on the membrane surface of human liver cancerHEPG cells.METHODS: LHRH was labeled by using 12sI with enzymaticreaction. The affinity and receptor volume of LHP, H-PE40and LHRH binding to LHRHR on the membrane surface ofhuman liver cancer cells were measured with radioligandreceptor assay.RESULTS: The specific activity of LHRH labeled with 12sIwas 2.7x 104 kBq/l^L, and its radiochemical purity reachedto 99.2-99.7%. The binding of 12sI to LHRH was maximalfor 240 min in the warm cultivation, and this binding wasstabilized. The inhibiting rates of ~2SI-LHRH and LHRH onthe proliferation of human liver cancer HEPG cells werenot significantly different. On the basis of the saturationcurve of ~2SI-LHRH binding to the membrane LHRHR of HEPGcells, ~2SI-LHRH of lx10s cpm was selected for radioligandreceptor assay. The affinity constants (Kd) of LHRH-PE40and LHRH binding to the membrane LHRHR of HEPG cellswere 0.43~0.12 nmol/L and 4.86~ 1.47 nmol/L, respectively,and their receptor volumes were 0.37~0.15 l^mol/g and0.42=I=0.13 l^mol/g, respectively. The binding of LHRH-PE40to the membrane protein of normal liver cells was notobserved.CONCLUSION: The recombinant toxin LHRH-PE40 binding tothe membrane surface of LHRHR of human liver cancer HEPGcells was very strong, while the specific binding of it to normalliver cells was not observed. The results provide an importantexperimental basis for the clinical application of LHRH-PE.
文摘The effects of two intraperitoneal injections of human chorionic gonadotropin (HCG) or [ D-ALA6, pro9- N- ethylamide]-luteinizing hormone releasing hormone analogue (LHRH-A), respectively, and the combined effect of LHRH-A with pimozide (PIM), a dopamine antagonist, on ovulation in female mud skipper were investigated. A high rate of ovulation (83.3%)was observed after injection with HCG(30 I. U./g). Injection of LHRH-A at a total dosage of 2μg/g was 100% effective in inducing ovulation. No ovulations occurred in the group receiving a low dosage of LHRH-A (0.02μg/g). Injection of LHRH-A(0.2μg/g)with PIM (10 or 20 μg/g)induced greater ovulatory response than injection with LHRH-A (0.2μg/g)alone. PIM at total dosages of 0.2μg/g or 2μg/g did not enhance the potency of LHRH-A to stimulate ovulation.
文摘Using fluoromctric technique wc tcstcd ED50 ofhistaminc release by LHRH antagonists.There wcrc 9 LHRH antagonists synthesized by us and tested by this method. The range of ED50 is from 0.65±0.08/μg / ml, to 36.8±2.8 /μg / ml. We selected a LHRH
文摘LHRH self-priming effect is simply defmed as an enhancement of LH response to LHRH, i. e., a second challenge with LHRH elicits more LH secretion as compared to the first challenge. The present study is to observe whether this phenomenon exists in perfused anterior pituitary (AP) cells of adult male rat. Dispersed AP cells of adult
