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Biomedical subjects

M Eda

Publications and source records attributed to M Eda.

29 records · Page 2Linked to original sources
PubMed1991

Novel 1,4-dihydropyridine calcium antagonists. II. Synthesis and antihypertensive activity of 3-[4-(substituted amino)phenylalkyl]ester derivatives.

Novel 1,4-dihydropyridine derivatives bearing 3-[4-(substituted amino)phenylalkyl]ester side chains were prepared and tested for their antihypertensive activity in spontaneously hypertensive rats. Most compounds showed a more potent antihypertensive effect and a longer duration of action than nicardipine. The derivatives with a benzhydrylpiperazinyl and a benzhydrylpiperidinyl group were distinctive. 2-[4-(4-Benzhydryl-1-piperazinyl)phenyl]ethyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (4e), its 4-(4-cyano-2-pyridyl) analogue (4f), its 3-[4-(4-benzhydryl-1-piperazinyl)phenyl]propyl ester analogue (4h), its 2-[4-(4-benzhydryl-1-piperidinyl)phenyl]ethyl ester analogue (4j), and its 2-[4-(1-benzhydryl-4-piperidinyl)phenyl]ethyl ester analogue (4k) were selected as candidates for further pharmacological investigations.

Animals↗
PubMed1991

[Pulsatile release of gonadotropins in athletic women].

In athletic women menstrual disorders such as luteal insufficiency, oligomenorrhea and amenorrhea are often seen. It has been suggested that such disorders may be related to hypothalamic-pituitary axis insufficiency caused by physical activity. To investigate the mechanism by which the disorder is promoted, episodic gonadotropin secretion was studied in 10 athletic women (normal ovulatory, 5; short luteal, 5) and 6 non-athletic controls. In the early follicular phase of the menstrual cycle, blood samples were obtained through an indwelling venous catheter at 15-minute intervals for 4 hours. The concentrations of luteinizing hormone (LH) and follicle-stimulating hormones (FSH) were measured by radioimmunoassay. The mean LH and FSH concentrations in the athletic groups were lower than those in the control group. LH pulse frequencies in the short luteal group were 2.8 +/- 0.2 times/four hours (mean +/- standard error) and decreased compared with that of the control group (3.7 +/- 0.2 times/four hours; p less than 0.001). The LH pulse amplitudes of all three groups were similar. Pulsatile FSH secretion was also observed in all the women. Dynamism of FSH was the same as that of LH except for low pulse amplitude in the athletic groups. These data suggest that hypothalamic-pituitary axis insufficiency, especially of hypothalamic origin may be caused by athletic activity.

Adult↗
PubMed1989

Effect of naloxone on hormonal changes during exercise.

It is well established that prolactin release during exercise is one of the important factors in exercise-induced menstrual dysfunction. The purpose of this study is to clarify the mechanisms of prolactin release during exercise. Ten female athletes measured their BBT every morning. They performed incremental exercise on a cycle ergometer, with or without naloxone, on the 5th to 8th days of the follicular phase. Three minutes before the exercise, 0.4mg of naloxone was injected intravenously and a further 1.6mg/hr of naloxone was continuously infused during exercise. Blood samples were collected after 60 minutes bed rest (Rest), at the time when the heart rates reached 150 bpm (Submax), the point of exhaustion (Max) during exercise and after 60 minutes bed rest following exercise (After 1hr). The levels of prolactin in serum, dopamine, beta-endorphin. VIP and ACTH in the plasma were measured. Whereas prolactin increased significantly at Submax (p less than 0.05) and Max (p less than 0.001), the increase in prolactin was suppressed by the administration of naloxone (p less than 0.05). Dopamine showed no remarkable change during exercise, with or without naloxone. There were significant increases in beta-endorphin at Max (p less than 0.001), VIP at Submax and Max (p less than 0.001), but these increases were suppressed by the administration of naloxone (p less than 0.001). ACTH which had markedly increased at Submax (p less than 0.025) and Max (p less than 0.001) showed a slight tendency to decrease following the administration of naloxone, but there were no significant differences in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Hormonal changes during continuous exercise in athletic women].

Recently, the number of women who participate in strenuous exercise has increased significantly. The relationship between delayed menarche and early onset of sports training, and increased incidence of menstrual dysfunction related to athletic activity had led to increased interest. Five basketball players who are among the best players in Japan were subjected to an investigation of endocrinological responses effected by 60 minutes continuous exercise cycle ergometer. The VO2max value was previously examined. Then, the level of load during exercise was established at 60% VO2max in this study. The serum level of estradiol increased significantly in the luteal phase but not so significantly in the follicular phase. Progesterone did not show a significant change during exercise. FSH increased slightly in both phases. However, LH showed a slight increase in the follicular phase and a slight decrease in the luteal phase. On the other hand, prolactin showed a continuous significant increase during exercise in both phases. These data suggested that strenuous daily training leads to a frequent significant increase in prolactin in athletic women and this frequent increase in prolactin may be one of the major factors causing menstrual dysfunction in athletic women. The specialized physician should be more concerned about the managing of athletes who are suffering from menstrual dysfunction.

Adult↗
PubMed1986

[Hormonal changes during incremental exercise in athletic women].

Recently, the number of women who participate in strenuous sports has increased rapidly. The evidence indicating a causal relationship between athletic activity and increased incidence of menstrual dysfunction has led to increased interest. Five basketball players who are among the top players in Japan were subjected to an investigation of the endocrinological responses effected by incremental exercise using a cycle ergometer. Serum levels of FSH and LH decreased significantly in the follicular phase, but there was no change in the luteal phase. Estradiol was seen to increase significantly in the luteal phase but no change occurred in the follicular phase. Progesterone did not show a significant change during exercise. Although TSH did not show any significant change, prolactin showed a significant increase in both phases. These results suggest that strenuous daily training leads to a frequent increase of prolactin in athletic women and this frequent increase of prolactin may be one of the major factors in causing menstrual dysfunction.

Adult↗
PubMed1986

[Effect of menstrual cycle on cardiorespiratory system during incremental exercise].

According to the results of questionnaires to college athletes, they believe the follicular phase is better than luteal phase for competitive sports. However, it is not clear whether there is significant difference in athletic performance between the two phases of the menstrual cycle. The effects of the menstrual cycle on the cardiorespiratory system were investigated in exercising women who are top players of basketball in Japan. They performed incremental exercise on a cycle ergometer. During the exercise, the ECG and heart rate (HR) were monitored. The expired air was sampled continuously and expiratory gas volume/minute (VE), oxygen uptake (VO2), carbon dioxide output (VCO2), gas exchange ratio(R) and respiratory rate (Resp. E.) were measured. Blood samples were collected to measure the blood lactic acid concentration during the exercise. HR in the luteal phase is higher than in the follicular phase at rest and throughout the exercise. VE, R and Resp. R. at rest and during exercise indicated a tendency to a higher level in the follicular phase. The blood lactic acid concentration during exercise in the follicular phase indicated a tendency to increase more rapidly than in luteal phase. However, no statistical differences in the cardiorespiratory system were detected when the follicular and luteal phase were compared. These results did not indicate conclusively in which phase it is better for athletic women to take part in competitive sports.

Adult↗
PubMed1984

[Menstrual characteristics in college athletes].

This study investigated the influences of endurance physical exercise on menstrual characteristics in college athletes. 311 college students at the University of Tsukuba (174: college athletes, 137: non-athletes, control students (group C) ) completed questionnaires which inquired about their menstrual history. College athletes were divided into two groups with hard physical activity (group A) and moderate physical activity (group B). The physical profile showed that group A and B had a lower total body water/body weight ratio than group C. The incidences of prolonged menstruation and hypomenorrhea of athletes were higher than those of non-athletes. There was no significant difference in the incidence of dysmenorrhea. However, the incidence of cases which required the medication to treat dysmenorrhea was lower in athletes than in non-athletes. Regarding the menstrual cycle, there was no significant difference in the incidence of oligomenorrhea and polymenorrhea in the three groups. On the other hand, the incidence of irregular menstrual cycles in group A was significantly higher than in group C. Athletes replied that the period of good physical condition during the menstrual cycles occurred in the late follicular and ovulatory phase. On the other hand, the period of bad condition was in the late luteal phase and during the menstrual period. Only 21.4% of athletes desire to regulate the menstrual cycle according to their sports schedule. The specialized physician should be more concerned either about managing the athletes who are suffering from menstrual dysfunction or about establishing a way to control the menstrual cycle.

Adolescent↗
PubMedDate not supplied

Selective determination of secondary amines as their N-diethylthiophosphoryl derivatives by gas chromatography with flame photometric detection.

A selective and sensitive method has been developed for the determination of secondary amines by gas chromatography (GC). After removal of primary amines by the reaction with o-phthaldialdehyde, secondary amines were converted into their N-diethylthiophosphoryl derivatives and then measured by GC with flame photometric detection using a DB-1701 capillary column. The derivatives were sufficiently volatile and stable to give single symmetrical peaks. The detection limits of secondary amines were ca. 0.05-0.2 pmol per injection. N-Methylcyclohexylamine was used as an internal standard. The calibration curves for secondary amines in the range 1-20 nmol were linear and sufficiently reproducible for quantitative determination. This method was successfully applied to small urine samples without prior clean-up. Overall recoveries of secondary amines added to urine samples were 91-105%. By using this method, secondary amines in urine samples could be analysed without any influence from primary amines and other coexisting substances. The analytical results of secondary amine content in urine samples of normal subjects are presented.

Amines↗