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Biomedical subjects

N Pedrón

Publications and source records attributed to N Pedrón.

At least 19 recordsLinked to original sources
PubMed2001

Measurement of androgen and estrogen receptors in breast tissue from subjects with anabolic steroid-dependent gynecomastia.

In order to assess the relationship between anabolic steroid administration and gynecomastia, we studied the effects produced by administering nandrolone decanoate and a mixture of propionate, phenilpropionate, isocaproate and testosterone decanoate to bodybuilders during a six month period. The following significant changes occurred: a 53% reduction in serum testosterone; LH and FSH levels were suppressed to 77% and 87%, respectively, in comparison to control values; and although 45% of the subjects showed an increase in serum estradiol levels, no statistically significant differences were found compared with control estradiol levels. With regard to estradiol and androgen receptors, 85% of gynecomastia tissue contained estradiol or androgen receptors, while 40% contained both. The mean values of estradiol and androgen receptors in the cytosol were 65 +/- 10 and 52 +/- 5 fmol/mg protein, respectively. Nuclear androgen and estradiol receptor levels were 33 +/- 7 and 67.5 +/- 9 fmol/mg protein, respectively. The presence of hormone receptors in gynecomastia receptive cells provides support for the hypothesis that gynecomastia is steroid-dependent.

Adult↗
PubMed2001

Effect of androgenic anabolic steroids on sperm quality and serum hormone levels in adult male bodybuilders.

The purpose of this study was to assess the influence of the administration of high doses of androgenic anabolic steroids (AAS) on endocrine and semen parameters. Thirty volunteering bodybuilders were studied (ages ranging between 26.6 +/- 4.1 years). A history of anabolic steroid administration was recorded for fifteen subjects, and results of semen analysis and endocrine parameters were compared with data from fifteen bodybuilders not using steroids. In those subjects using AAS, eight had sperm counts under the lower normal limit (20 x 10(6) sperm/ml), three had azoospermia, two polyzoospermia, and two had normal sperm counts. The percentage of morphologically normal sperm was significantly reduced, only 17.7% had normal spermatozoa. In the control group, only one subject had oligozoospermia. The hormonal parameters revealed reduced FSH (1.5 +/- 3.2 vs 5.0 +/- 1.6, p < 0.001) and PRL (5.1 +/- 4.9 vs 9.2 +/- 4.4, p < 0.01) levels. LH, T, E2 and DHEA levels did not vary.

Adult↗
PubMed1999

[beta-Endorphins and the male reproductive system].

In the antique Chinese culture, it was already known about opioide for therapeutic usage. On 1975, Hughes et al., identificated two endogen pentapetides with potent opiate activity Leu-enkephalin and Met-enkephalin, ever since beta-Endorphin have been considered involucrated in many biological functions. beta-Endorphin have found in testis, seminal vesicle and prostate in different species. It has been observed a paracrine effect between in Leydig and Sertoli cells and inhibit the basal release of LH in man by inhibiting its pulsatile discharge. In this paper is discussed, in a general way, localization and production sites of beta-Endorphin especially their participation in male reproductive tract-physiology. Finally, it is mentioned the experimental methodology to identify and quantify beta-Endorphin in blood plasma and semen.

Humans↗
PubMed1998

Effect of naloxone on serum prolactin levels in adult male rabbits.

In order to clarify the possible physiological role of endogenous opioid peptides (EOP), we studied the effect of low doses of naloxone (specific opiate antagonist) on plasma prolactin levels in male rabbits. Five groups of five male rabbits each was injected daily between 8-9 a.m., with naloxone 12.5, 25, 50, 100 and 200 microg/kg/day. An additional group of ten animals was injected with saline solution and considered the control group. Blood samples were taken at baseline before naloxone administration and later at 90 min and 1, 2, 4, 7, 10 days after its administration. Samples were also taken 4 days after stopping naloxone administration (day 14). Plasma prolactin levels were measured by RIA. A significant constant decrease in PRL levels was seen with the 12.5 microg at 90 minutes, while with the remaining doses a progressive decrease was recorded throughout the study.

Animals↗
PubMed1988

The zoapatle. XV. Activity of 16 alpha-hydroxy-ent-kauran-19-oic acid isolated from Montanoa hibiscifolia, and its methyl ester on rat and guinea pig uterus.

16 alpha-Hydroxy-ent-kauran-19-oic acid was isolated from Montanoa hibiscifolia. The effects of this acid and its methyl ester on the contractile activity of rat and guinea pig uterine horns were studied. Both inhibited spontaneous, oxytocin-induced and potassium-induced contractile activities. The inhibitory effect produced by the methyl ester was greater than that observed with the acid. The methyl ester was 2-5 times more potent than the acid upon spontaneous and potassium-induced contractions and 11-15 times more potent than the acid upon the contractile activity of uterine smooth muscle induced by oxytocin. Such effects were observed using bath concentrations of 6, 15, 30 and 60 microM of each compound.

Animals↗
PubMed1987

Estimates of post-partum bleeding.

Post-partum bleeding was estimated during the first 72 hours in 106 women with normal delivery at term, all had live child with a body weight between 2.5 and 3.5 Kg. Three groups of women were studied: Group 1 comprised 41 volunteers with normal deliveries to whom no medication had been administered; Group 2 comprised 39 volunteers receiving 20 IU of oxytocin in 250 ml of a 5% glucose solution, immediately after delivery; and in Group 3, 26 volunteers received 0.2 mg of ergonovine maleate, orally three times daily for three days. The average post-partum blood loss in Group 1 during the first 72 hours after delivery was 151.5 +/- 12.5 ml; for Group 2, 155.9 +/- 13.9 ml; and for Group 3, 135.5 +/- 15.9 ml. There were no significant differences among the groups and, most of the blood loss occurred during the first 24 hours after delivery.

Adult↗
PubMed1987

The effect of post-partum IUD insertion on post-partum bleeding.

Post-partum bleeding was measured for 72 hours in 66 volunteer healthy women after normal pregnancy and delivery at term. After complete placenta expulsion, a 220C Copper T was placed by the attending physician in 33 volunteer subjects before leaving the delivery room. Similar number of volunteer subjects served as a control. Post-partum bleeding during the 72 hours of study was 134.7 +/- 16.3 ml for the IUD group and 155.9 +/- 16.0 ml for the control group. No differences were detected among the two groups. Hemoglobin levels were the same for both groups, being at 72 hours after delivery, 11.9 +/- 0.28 gm/ml for the IUD group and 12.2 +/- 0.36 for controls. None of the women with immediate post-partum IUD insertion had any changes in the normal characteristics of their post-partum period.

Adult↗
PubMed1987

The effect of acetylsalicylic acid on menstrual blood loss in women with IUDs.

Fifty-three volunteer women using Copper T 220C IUDs, complaining of increased menstrual bleeding, received per os 1 g, three times a day, of acetylsalicylic acid, for 5 days, during their menstrual periods. Menstrual bleeding for each patient was measured at least once before treatment. Bleeding estimates were also performed from the second to the fifth treatment cycle. From the 53 women admitted to the study, only 13 subjects (24.7%) had pre-treatment menstrual bleeding of more than 80 ml; 40 subjects had less than 80 ml. The group with hypermenorrhea had slightly decreased (not significant) the amount of menstrual blood loss with acetylsalicylic acid intake. On the other hand, 67.1% of women with bleeding less than 80 ml observed a significant increase in menstrual blood loss.

Adult↗
PubMed1986

Zoapatle. XII. In vitro effect of kaurenoic acid isolated from Montanoa frutescens and two derivatives upon human spermatozoa.

Zoapatle aqueous crude extract (ZACE) from Montanoa tomentosa has been used as an oral contraceptive in traditional Mexican medicine for centuries. Kaurenoic acid, as isolated from Montanoa frutescens, and the methyl esters of 15-hydroxy-dihydro-kaurenoic acid and 15-keto-dihydro-kaurenoic acid were tested in vitro on human sperm motility and viability. The estimated ED50 concentrations immobilization were 374, 126 and 58 micrograms/ml, respectively using 15 X 10(6) sperms/500 microliter. Kaurenoic acid and both of its derivatives displayed only weak to negligible capacity for killing human sperms.

Diterpenes↗
PubMed1985

The zoapatle. VII. Antiimplantation effect in the rat of zoapatle aqueous crude extract (ZACE) from Montanoa tomentosa and Montanoa frutescens.

Intrauterine administration of zoapatle aqueous crude extract (ZACE) from Montanoa frutescens on the fourth day of rat pregnancy, at concentrations equivalent to 50 mg and 5 mg of dry leaves, was associated with total inhibition of implantation sites. On the other hand, ZACE from Montanoa tomentosa equivalent to 50 and/or 100 mg of dry leaves, prepared and administered in the same fashion, did not inhibit the number of implants by day 11 of pregnancy. However, most implants were found abnormal, of blue color, poor orientation or spacing; these morphological changes could be considered as reabsorption sites.

Animals↗
PubMed1985

The zoapatle. VIII. Ultrastructural changes in endometrium of rats.

Intrauterine administration of Zoapatle aqueous crude extract (ZACE) prepared from Montanoa tomentosa s.s.p. tomentosa, on day 4 of pregnancy, did not alter the normal uterine morphological changes by days 5 and 8 of pregnancy in the rat. On the other hand, ZACE made from Montanoa frutescens caused profound alterations on the uterine structures, such as: focal loss of epithelial lining, thickened blood vessels and alterations in stroma cells in rat endometrium. Morphological alterations correlate well with the antiimplantation effect associated with the intrauterine administration of these plant extracts. Scanning electron micrographs of leaves from Montanoa tomentosa and Montanoa frutescens revealed striking differences in glandular secretion and trichomes.

Animals↗
PubMed1985

The zoapatle. IX. In vitro effect of Montanoa tomentosa and Montanoa frutescens upon human sperm and red cells.

The effect of zoapatle aqueous crude extract (ZACE) was further studied and partially characterized upon human and rabbit spermatozoa. ZACE prepared from Montanoa tomentosa s.s.p tomentosa did not influence sperm motility or viability in a wide range of ZACE concentrations tested; on the other hand, ZACE prepared from Montanoa frutescens had immediate and constant inhibitory effect upon motility and decreased cell viability. Red cell lysis was readily observed with ZACE-frutescens, but not with ZACE-tomentosa. The effect of time on ZACE-frutescens potency for inducing red cell lysis was observed.

Animals↗
PubMed1985

The zoapatle. X. The in vitro effect of zoapatle aqueous crude extract (ZACE) and histamine upon rat and guinea pig uterine strips.

In vitro histamine response in rat and guinea pig uterine strips was similar to the one observed with zoapatle aqueous crude extract (ZACE). The relaxing effect elicited by ZACE/tomentosa on the in vitro rat uterine strips was not mediated by activation of H-2 histamine receptors; moreover, the increase on uterine contractility elicited by ZACE/tomentosa on the in vitro guinea pig uterine strip was not mediated through the activation of H-1 histamine receptors.

Animals↗
PubMed1985

The zoapatle. XI. Effects elicited by Montanoa tomentosa and Montanoa frutescens on rat uterine strips.

Zoapatle aqueous crude extract (ZACE) obtained from Montanoa tomentosa (M.t.) inhibits the in vitro spontaneous contractility pattern of rat uterine tissue. The opposite effect was observed with ZACE from Montanoa frutescens (M.f.) in the same preparation. Both plant extracts, M.t. and M.f., increased the in vitro spontaneous contractility pattern in the uterine guinea pig assay. In depolarized uterine tissue, propranolol (beta-blocker) inhibited the relaxing effect induced by M.t.. Atropine (cholinergic antagonist) abolished the increase in uterus contractility produced by the presence of M.f.

Acetylcholine↗
PubMed1985

Serum lipid levels before and after vasectomy in men.

The blood lipid profile was determined in sixty-two men, 24 to 62 years old, before and two, six and twelve months after surgical occlusion of the vas deferens. No statistically significant differences were found in mean body weight, blood pressure, serum levels of non-esterified fatty acids, total lipids, triglycerides, total cholesterol and alpha, beta and prebeta fractions of the lipoproteins, which were measured before and after surgery. When the serum levels of the alpha and beta fractions were considered in the same subject, it was observed that 12 months after vasectomy a similar percentage of cases showed a predominance of either one of them. Hence, no modifications on the lipid profile of these subjects were found that could indicate an increased risk of arteriosclerotic disease.

Adult↗
PubMed1983

The zoapatle IV--toxicological and clinical studies.

The zoapatle aqueous crude extract has been used in Mexico for the last 5 centuries for the induction of labor, treatment of post-partum bleeding problems, and as a menses inducer. Today, it is sold in street markets, and its long documented history of use by humans could be taken as indirect evidence of a lack of toxicity. Rigorous pharmacological and clinical studies described here, fully confirm the empirical observations.

Animals↗