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Biomedical subjects

C Y Hong

Publications and source records attributed to C Y Hong.

At least 163 records · Page 9Linked to original sources
PubMed1985

Calcium antagonists stimulate sperm motility in ejaculated human semen.

Three calcium antagonists, diltiazem, flunarizine and verapamil stimulated human sperm motility in vitro. Among them, diltiazem induced the largest amplitude of motility increase. The concentration-response curve of diltiazem was similar in shape to those of calcium chelators. EGTA, a calcium chelator, potentiated the stimulatory effect of diltiazem while A23187, a calcium ionophore, antagonized it. These observations supported our previous hypothesis that an increased concentration of calcium ion was detrimental to human sperm motility. Whether calcium antagonists could be used in the treatment of subfertile patients awaits further investigation.

Calcimycin↗
PubMed1985

Involvement of calcium in the caffeine stimulation of human sperm motility.

The shape of the concentration-response curve and the amplitude of maximal motility increase for the stimulatory effect of caffeine on human sperm motility were similar to those of EGTA, a calcium chelator, and lanthanum chloride, a calcium entry blocker. On the other hand, the maximal motility stimulation induced by dibutyryl cyclic AMP was similar to that induced by trifluoperazine, a calmodulin antagonist. The antagonism of A23187 on the motility-stimulating effect of EGTA and caffeine was competitive in nature, while that on cyclic AMP was non-competitive. We proposed that there could be two mechanisms for caffeine to stimulate sperm motility: at higher concentrations, caffeine modified calcium translocation; at lower concentrations, caffeine increased cyclic AMP level. The importance of calcium in the regulation of human sperm motility was reconfirmed in this study.

Bucladesine↗
PubMed1985

Screening the in vitro sperm-immobilizing effect of some anticancer drugs.

The in vitro sperm-immobilizing effect of seven anticancer agents, namely cyclophosphamide, 5-fluorouracil, cytarabine, mitomycin-C, 6-mercaptopurine, doxorubicin and vinblastine were screened with a transmembrane migration method. Only doxorubicin and vinblastine inhibited human sperm motility. Because colchicine, a microtubular inhibitor, had no sperm-immobilizing effect, we suggest that the sperm membrane is the site of action of these two anticancer drugs to inhibit human sperm motility.

Antineoplastic Agents↗
PubMed1985

Activities of transport adenosine triphosphatases in erythrocyte membranes of healthy and hypertensive subjects.

The Na+, K+-ATPase activity in the erythrocyte membrane was measured in 25 untreated essential hypertensive patients and 25 age-matched healthy normotensive subjects. In addition, the Ca2+, Mg2+-ATPase activity was measured in 20 hypertensive and 25 age-matched normotensive subjects. The Na+, K+-ATPase activity of healthy Chinese measured in this study was similar to the data reported in a Dutch study. We therefore could not support a theory which speculated an ethnic influence on Na+, K+-ATPase activity. Both Na+, K+-ATPase and Ca2+, Mg2+-ATPase activities were slightly lower in hypertensive patients as compared with those in normotensive subjects, but the differences were not statistically significant. We concluded that the transport ATPase activities were not impaired in the erythrocyte membranes of hypertensive patients.

Adult↗
PubMed1985

Lack of influence of aluminum hydroxide on the bioavailability and beta-adrenoceptor blocking activity of propranolol.

Plasma concentrations of propranolol and the changes of exercise induced heart rate were determined in 6 healthy subjects. An amount of 40 mg of propranolol was given alone or in combination with 30 ml of aluminum hydroxide gel. Neither the bioavailability nor the beta-adrenoceptor blocking activity of propranolol was significantly changed by concurrent administration of aluminum hydroxide gel. There is no need to increase the propranolol dose when aluminum hydroxide gel is administered concurrently.

Adult↗
PubMed1984

Calcium ion is the key regulator of human sperm function.

Calcium ions have an apparently paradoxical effect on sperm motility. In the epididymis, calcium ions stimulate immature sperm, whereas, in ejaculated semen, calcium ions inhibit sperm motility. Maturation processes change the response of sperm to calcium ions. Calcium binding substances and calcium transport inhibitors are secreted by male accessory sexual organs and mixed with sperm during ejaculation. In the female genital tract sperm acquire full capacity of fertilise the ovum. Calcium binding substances and calcium transport inhibitors are removed during the process known as capacitation. Finally, calcium ions trigger the acrosome reaction and facilitate sperm penetration into the ovum.

Acrosome↗
PubMed1984

Local anaesthetic effect of antiarrhythmic drugs and human sperm immobilization: mechanism and application of the interrelationship.

Sperm immobilizing activity of three class I antiarrhythmic drugs, quinidine, procainamide, mexiletine, one adrenoceptor blocking drug, labetalol and one calcium channel blocking drug, diltiazem was measured with a trans-membrane migration method. All these drugs immobilized human sperm. Local anaesthetic effect is the underlying mechanism for these drugs to inhibit sperm motility. Sperm immobilization could be a screening test for the local anaesthetic effect of antiarrhythmic drugs.

Anesthetics, Local↗
PubMed1984

Glutathione and caffeine antagonize the sperm-immobilizing effect of a vaginal contraceptive.

The concentration-dependent inhibition of Neosampoon, a vaginal contraceptive, on ejaculated human sperm motility was studied with a transmembrane migration method. Caffeine (5mM), glutathione (5mM) and glutathione (15mM) all reactivated the motility of Neosampoon-immobilized sperm. Caffeine (5mM) was more potent than glutathione in antagonizing Neosampoon; there was no difference between the potency of 5mM- and 15mM-glutathione. Human sperm motility could be a model for studying the interaction of membrane-active drugs, including the protective effect of glutathione against membrane-disrupting agents.

Caffeine↗
PubMed1984

Sperm immobilizing potency of amitriptyline and imipramine: measured with transmembrane migration.

The inhibitory effect of amitriptyline and imipramine on human sperm motility was measured in vitro with a transmembrane migration method. The EC50 for amitriptyline and imipramine were 170 microM and 160 microM respectively. They were more potent than any other drug that had been tested on this pharmacological model. Transmembrane migration method was less sensitive than turbidimetric method to detect the sperm immobilizing effect of drugs.

Amitriptyline↗
PubMed1984

[Cephalosporin C production by solid state fermentation with rice grains].

The purpose of the present study was to investigate the production of cephalosporin C in solid state fermentation with rice as a basal substrate. Among the various grains as basal substrates tested, rice was the best one and the worst one was soyflour . Among the varieties of rice examined, Tsailai rice was the best. The proposed best formula for the fermentation medium on the basis of 10 g rice grain consists the following % of the ingredients, 0.65, peptone, 0.65, ammonium sulfate, 0.26, inositol, 1.3 (v/w), trace element solution, 0.65 calcium carbonate, 0.65 calcium sulfate, 0.065, potasium sulfate, 1.3, sucrose, 0.13, DL-methionine and 2.6, methyl oleate. Of the strains of C. acremonium used, strain M8650 -R-3 was superior to strain ATCC 14553. The optimum inoculum density was 2.8 X 10(8) spores of C. acremonium M8650 -R-3 per g substrate. The initial moisture content of the medium at 49-51%, the water activity at 0.985, and the fermentation temperature at 25 degrees C were found as the optimun . After 7 days of fermentation, the maximum yield of cephalosporin C was 6420 micrograms per g substrate and the total cephalosporin C equivalent potency was 11,000 micrograms per g substrate.

Acremonium↗
PubMed1983

Mitochondrial respiration inhibitors and human sperm motility: implication in the development of spermicides.

Three inhibitors of the mitochondrial respiratory chain, rotenone, antimycin A, potassium cyanide and the uncoupler of oxidative phosphorylation, 2,4-dinitrophenol, were tested for their sperm immobilizing effects with a trans-membrane migration method. None of these drugs inhibited human sperm motility at the concentrations of 10(-6), 10(-5), 10(-4) and 10(-3) M. The suggestion to develop spermicidal contraceptives from mitochondrial respiration inhibitors could not be substantiated; and the theory that motility inhibiting drugs act primarily on the sperm membrane was reconfirmed.

Antimycin A↗
PubMed1983

Importance of membrane stabilizing effect in massive overdose of propranolol: plasma level study in a fatal case.

Plasma propranolol levels were measured in a woman who took 3120 mg of propranolol in a suicide attempt. Highest plasma level, measured at the 12th hour, was 1475 ng/ml. Elimination half life was prolonged to 13.8 h. She suffered from coma and profound hypotension, then died on the 20th day. By estimating brain propranolol concentration from the plasma level, and reviewing the clinical pictures of previously reported cases, we propose that central nervous suppression by propranolol, with membrane stabilizing effect as its pharmacological basis, may cause life threatening abnormalities in patients with massive overdose of propranolol.

Action Potentials↗
PubMed1983

Quantitative evaluation of the spermicidal potencies of vaginal contraceptives with a transmembrane migration method.

The spermicidal potencies of four vaginal contraceptives, namely Delfen cream, Samtol tablet, Lorophyn suppository and Ortho-Gynol jelly were compared using a transmembrane migration method which measured the proportion of sperm that moved from a semen-drug mixture across a Nuclepore membrane with 5 micron pores into phosphate buffer. The concentration-response curves of all preparations were parallel. The maximal dilutions that decreased sperm motility to 50% of control for Delfen, Samtol, Lorophyn and Ortho-Gynol were 240, 160, 75 and 35 respectively. The trans-membrane migration method is a simple, reproducible and quantitative test for evaluating the spermicidal potencies of vaginal contraceptives.

Depression, Chemical↗
PubMed1982

Effects of chlorpromazine and other drugs acting on the central nervous system on human sperm motility.

The in vitro effects of chlorpromazine, diazepam, phenytoin and phenobarbitone on human sperm motility were investigated. Only chlorpromazine inhibits human sperm motility and the concentration which decreases sperm motility to 50% of control is 0.22 mM. Caffeine can shift the dose-response curve of chlorpromazine-inhibited sperm motility to right. We support the hypothesis that chlorpromazine acts on the cellular membrane but consider the inhibition of sperm motility an unlikely cause of decreased fertility in chlorpromazine treated patients.

Caffeine↗