Relação do proteinograma sérico e as fases folicular e luteal do ciclo estral em éguas / Relation of the serum proteins and the follicular and luteal phasesof the estrous cycle in mares

O objetivo deste estudo foi obter o perfil eletroforético das proteínas séricas em éguas cíclicas e verificar as diferenças entre as fases folicular e luteal do ciclo estral nesta espécie. Foram utilizadas 18 éguas, totalizando 36 amostras de soro, sendo duas de cada égua. As amostras foram colhidas no estro e no diestro. As proteínas séricas totais foram obtidas pelo método do Biureto, a partir da utilização de Kits comerciais (LABTEST®) e, as diferentes subfrações proteicas, por eletroforese em gel de poliacrilamida (SDS-PAGE). O eletroforetograma das proteínas séricas colocou em evidência a presença de 17 a 25 frações proteicas, cujos pesos moleculares variaram de 22 a 254 kDa. Identificaram-se duas proteínas ainda não nomeadas oficialmente, de massas moleculares (MM) 23 kDa e 144 kDa. Os valores médios ± SEM obtidos para cada variável no estro e no diestro, respectivamente, foram: proteínas totais (g/dL) 7,11 ± 0,07 e 7,36 ± 0,07; albumina (mg/dL) 4790,83 ± 69,10 e 5027,19 ± 69,10; α1 glicoproteína ácida (mg/dL) 4,90 ± 0,31 e 4,93 ± 0,31; ceruloplasmina (mg/dL) 15,28 ± 1,31 e 10,65 ± 1,31; haptoglobina (mg/dL) 22,70 ± 1,16 e 27,06 ± 1,16; transferrina (mg/dL) 329,00 ± 9,78 e 350,16 ± 9,78; IgA (mg/dL) 119,91 ± 6,30 e 107,03 ± 6,30; IgG (mg/dL) 1525,07 ± 40,18 e 1517,25 ± 40,18; MM 23 (mg/dL) 204,44 ± 8,61 e 219,79 ± 8,61; MM 144 (mg/dL) 22,13 ± 0,55 e 21,49 ± 0,55. Não houve diferença significativa das proteínas totais e suas frações do estro para o diestro. Conclui-se que as modificações hormonais durante as fases do ciclo estral da égua não interferem no proteinograma sérico.

This study aimed to obtain the electrophoretic profile of serum proteins in cyclic mares and to verify the differences between the follicular and luteal phases of the estrous cycle in this species. Eighteen mares were used, totaling 36 serum samples, two of each mare. Samples were collected both in estrus and in diestrus. Total serum proteins were obtained by the Biureto method, by using commercial kits (LABTEST®), while the different protein subfractions by polyacrylamide gel electrophoresis (SDS-PAGE). The electroforetogram of serum proteins evidenced the presence of 17 to 25 protein fractions, whose molecular weights ranged from 22 to 254 kDa. Two proteins that were not yet officially named were identified, of molecular weights (MW) of 23 kDa and 144 kDa. The mean values (± SEM) obtained for each variable in estrus and diestrus were, respectively: total proteins (g/dL) 7.11 ± 0.07 and 7.36 ± 0.07; albumin (mg/dL) 4790.83 ± 69.10 and 5027.19 ± 69.10; α1 acid glycoprotein (mg/dL) 4.90 ± 0.31 and 4.93 ± 0.31; ceruloplasmine (mg/dL) 15.28 ± 1.31 and 10.65 ± 1.31; haptoglobine (mg/dL) 22.70 ± 1.16 and 27.06 ± 1.16; transferrin (mg/ dL) 329.00 ± 9.78 and 350.16 ± 9.78; IgA (mg/dL) 119.91 ± 6.30 and 107.03 ± 6.30; IgG (mg/dL) 1525.07 ± 40.18 and 1517.25 ± 40.18; MW 23 (mg/dL) 204.44 ± 8.61 and 219.79 ± 8.61; MW 144 (mg/dL) 22.13 ± 0.55 and 21.49 ± 0.55. No significant difference was verified in total proteins and its fractions in estrus and diestrus. The hormonal changes during the specific stages of the estrous cycle of the mare do not interfere with the serum proteinogram.

Measurement of serum estrogen and estrogen metabolites in pre- and postmenopausal women with osteoarthritis using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry

Although 17β-estradiol (E2) deficiency has been linked to the development of osteoarthritis (OA) in middle-aged women, there are few studies relating other estrogens and estrogen metabolites (EMs) to this condition. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to measure the levels of six EMs (i.e., estrone, E2, estriol, 2-hydroxyestrone, 2-hydroxyestradiol, and 16a-hydroxyestrone) in healthy pre- and postmenopausal women and women with OA. This method had a precision ranging from 1.1 to 3.1% and a detection limit ranging from 10 to 15 pg. Compared to healthy women, serum-free E2 was lower in the luteal and postmenopausal phases in women with OA, and total serum E2 was lower in postmenopausal women with OA. Moreover, compared to healthy women, total serum 2-hydroxyestradiol was higher in postmenopausal women with OA and total serum 2-hydroxyestrone was lower in both the luteal and follicular phases in women with OA. In conclusion, our HPLC-ESI-MS/MS method allowed the measurement of multiple biochemical targets in a single assay, and, given its increased cost-effectiveness, simplicity, and speed relative to previous methods, this method is suitable for clinical studies.

Disturbances in the serum progesterone levels during the luteal phase

The major cause of female infertility is the disturbance of the hormones of hypothalamic-pituitary-gonadal axis and progesterone is a major component of this axis. The present study was carried out to determine the incidence of luteal phase defect of progesterone in a group of 150 regularly menstruating female subjects. Luteal phase defect to progesterone was seen in 43.3% patients, 40% having fairly low level of progesterone and 3.3% exhibiting higher levels

Luteal phase of the menstrual cycle increases sweating rate during exercise

The present study evaluated whether the luteal phase elevation of body temperature would be offset during exercise by increased sweating, when women are normally hydrated. Eleven women performed 60 min of cycling exercise at 60 percent of their maximal work load at 32°C and 80 percent relative air humidity. Each subject participated in two identical experimental sessions: one during the follicular phase (between days 5 and 8) and the other during the luteal phase (between days 22 and 25). Women with serum progesterone >3 ng/mL, in the luteal phase were classified as group 1 (N = 4), whereas the others were classified as group 2 (N = 7). Post-exercise urine volume (213 ± 80 vs 309 ± 113 mL) and specific urine gravity (1.008 ± 0.003 vs 1.006 ± 0.002) changed (P < 0.05) during the luteal phase compared to the follicular phase in group 1. No menstrual cycle dependence was observed for these parameters in group 2. Sweat rate was higher (P < 0.05) in the luteal (3.10 ± 0.81 g m-2 min-1) than in the follicular phase (2.80 ± 0.64 g m-2 min-1) only in group 1. During exercise, no differences related to menstrual cycle phases were seen in rectal temperature, heart rate, rate of perceived exertion, mean skin temperature, and pre- and post-exercise body weight. Women exercising in a warm and humid environment with water intake seem to be able to adapt to the luteal phase increase of basal body temperature through reduced urinary volume and increased sweating rate.

Actividad ovárica del tepezcuintle Agouti paca (Rodentia: Agoutidae) en cautiverio / Ovarian activity of Agouti paca (Rodentia: Agoutidae) under captivity

The ovarian activity of Agouti paca was characterized by hormonal profiles and ovarian structures. Samples of blood were taken from eight females (seven adults and one juvenile) at the breeding grounds of the Facultad de Medicina Veterinaria y Zootecnia in Yucatsn, Mexico. Sampling lasted approximately two months and was done every three and six days. Blood was collected from anesthetized animals, and the levels of progesterone (P4) and 17 beta estradiol (E2) were analized by radioimmunoassay technique. Macroscopic and microscopic analyses were carried out in ovaries of dead animals. The estrous cycle lasted 29+/-8.4 days, levels of 1.61+/-0.65 ng/ml for P4 and 39+/-24 pg/ml for E2 were observed for a follicular phase, 6.18+/-3.70 ng/ml and 29+/-16 pg/ml for P4 and E2 respectively in the luteal phase. Statistically significant differences were found between phases for P4 but not for E2. The presence of extragonadal steroids with levels of P4 of 1.9+/-0.77 ng/ml and E2 of 22+/-17 pg/ml were observed, which are not produced by the effects of managing stress. The changes in the levels of P4 during the cycle are indicators of luteal activity, with the intersticial tissue acting probably as active steroids-producing gland. Follicular growth was observed during the entire cycle.

Se caracterizó la actividad ovárica de A. paca por medio de perfiles hormonales y estructuras ováricas. Se muestrearon ocho hembras (siete adultas y una juvenil) en el criadero de la Facultad de Medicina Veterinaria y Zootecnia en el estado de Yucatán, México, durante aproximadamente dos meses. Se recolectaron muestras sanguíneas cada 3 y 6 días en animales anestesiados. Se estimaron los niveles de progesterona (P4) y 17 beta estradiol (E2) sanguíneos por radioinmunoanálisis. Las estructuras ováricas de animales muertos durante el periodo de muestreo fueron analizadas macro y microscópicamente. El ciclo ovárico duró 29±8.4 días, con niveles de 1.61±0.65 ng/ml para P4 y de 39±24 pg/ml para E2 durante la fase folicular, y de 6.18±3.70 ng/ml y 29±16 pg/ml para P4 y E2 respectivamente, en la fase luteal. Hubo diferencias (p<0.05) en los niveles de P4 entre las fases folicular y luteal, no así para E2. Se detectó la presencia de esteroides extragonadales, con niveles de 1.9±0.77 ng/ ml para P4 y de 22±17 pg/ml para E2, los cuales no son secretados por efecto del estrés por manejo. Los cambios en los niveles de P4 durante el ciclo son indicadores de actividad luteal, funcionando el tejido intersticial probablemente como una glándula productora de esteroides. De igual forma se observó que el crecimiento folicular ocurre durante todo el ciclo.

Effects of metformin treatment on luteal phase progesterone concentration in polycystic ovary syndrome

The causes of luteal phase progesterone deficiency in polycystic ovary syndrome (PCOS) are not known. To determine the possible involvement of hyperinsulinemia in luteal phase progesterone deficiency in women with PCOS, we examined the relationship between progesterone, luteinizing hormone (LH) and insulin during the luteal phase and studied the effect of metformin on luteal progesterone levels in PCOS. Patients with PCOS (19 women aged 18-35 years) were treated with metformin (500 mg three times daily) for 4 weeks prior to the test cycle and throughout the study period, and submitted to ovulation induction with clomiphene citrate. Blood samples were collected from control (N = 5, same age range as PCOS women) and PCOS women during the late follicular (one sample) and luteal (3 samples) phases and LH, insulin and progesterone concentrations were determined. Results were analyzed by one-way analysis of variance (ANOVA), Duncan's test and Karl Pearson's coefficient of correlation (r). The endocrine study showed low progesterone level (4.9 ng/ml) during luteal phase in the PCOS women as compared with control (21.6 ng/ml). A significant negative correlation was observed between insulin and progesterone (r = -0.60; P < 0.01) and between progesterone and LH (r = -0.56; P < 0.05) concentrations, and a positive correlation (r = 0.83; P < 0.001) was observed between LH and insulin. The study further demonstrated a significant enhancement in luteal progesterone concentration (16.97 ng/ml) in PCOS women treated with metformin. The results suggest that hyperinsulinemia/insulin resistance may be responsible for low progesterone levels during the luteal phase in PCOS. The luteal progesterone level may be enhanced in PCOS by decreasing insulin secretion with metformin.

Secreçäo pulsátil de progesterona em mulheres ovulatórias normais e em mulheres com defeitos da fase lútea / Pulsatile progesterone secretion in normal ovulatory women wiht luteal ohase defects

Neste trabalho avaliamos a secreçao pulsátil de P(4) na fase lútea de mulheres ovulatórias normais e mulheres com LPD. Observamos que nao houve diferença significativa entre os grupos em relaçao aos níveis basais, secreçao média e outros parâmetros da secreçao pulsátil (amplitude absoluta e freqüência), a nao ser a amplitude percentual dos pulsos. Portanto, a dosagem exclusiva de P(4), valores absolutos ou secreçao pulsátil, nao se presta ao diagnóstico de LPD, necessitando de outros métodos omplementares.

Serum calcium, magnesium and inorganic phosphorous levels during various phases of menstrual cycle.

Serum Calcium (Ca), Magnesium (Mg) and Inorganic phosphorous (Pi) were investigated serially during menstrual, follicular, ovulatory and luteal phases of menstrual cycle in 25 healthy medical student volunteers. The result shows significant cyclic variations within physiological limits in all parameters. Ca level was highest during ovulation (P < 0.001) and lowest during luteal phase (P < 0.001) compared to other phases. Exactly opposite result was observed for Ca level. It is lowest during ovulation (P < 0.001) and highest during the luteal phase (P < 0.001). However, the highest level of Pi was seen during menstrual phase (P < 0.001) and lowest during the luteal phase (P < 0.001). These changes are probably brought about under the influence of cyclic variations of the ovarian hormones.