Prolactin Hormone and Cardiovascular System.

The Prolactin (PRL) hormone, a very ancient hormone, first discovered by Oscar Riddle and his colleagues in the late 1920s, is a 199 amino acid multifunctional polypeptide hormone, that has been found in all vertebrates to influence more than 300 physiologic functions of the body. This review discusses the prolactin structure, mechanism of synthesis, control of secretions, receptors, its intracellular signal transduction and its possible implications on the cardiovascular system.

Bioassay of pituitary prolactin of the lizard uromastix hardwickii

The present study has been designed to evaluate the pituitary prolactin in the lizard Uromastix hardwickii. Pituitary glands were removed from 24 lizards and a suspension was prepared. This suspension was injected in the crop sac glands of a group of 12 pigeons. Another group of 12 pigeon was injected distilled water instead. Results of the study indicate a mean crop gland diametric response of 0.8cm following pyrogen free distilled water administration. Whereas following the administration of pituitary suspension the response was of 2.12cm. The first response was due to injection stress and the latter response was due to PRL

Is the infertility in hypothyroidism mainly due to ovarian or pituitary functional changes?

The objective of the present study was to examine whether hypothyroidism affects the reproductive system of adult female rats by evaluating ovarian morphology, uterus weight and the changes in serum and pituitary concentrations of prolactin and gonadotropins. Three-month-old female rats were divided into three groups: control (N = 10), hypothyroid (N = 10), treated with 0.05 percent 6-propyl-2-thiouracil (PTU) in drinking water for 60 days, and T4-treated group (N = 10), receiving daily sc injections of L-thyroxine (0.8 æg/100 g body weight) during the last 10 days of the experiment. At the end of 50 days of hypothyroidism no hypothyroid animal showed a regular cycle, while 71 percent of controls as well as the T4-treated rats showed regular cycles. Corpora lutea, growing follicles and mature Graafian follicles were found in all ovaries studied. The corpora lutea were smaller in both the hypothyroid and T4-replaced rats. Graafian follicles were found in 72 percent of controls and only in 34 percent of hypothyroid and 43 percent of T4-treated animals. Serum LH, FSH, progesterone and estradiol concentrations did not differ among the three groups. Serum prolactin concentration and the pituitary content of the three hormones studied were higher in the hypothyroid animals compared to control. T4 treatment restored serum prolactin concentration to the level found in controls, but only partially normalized the pituitary content of gonadotropins and prolactin. In conclusion, the morphological changes caused by hypothyroidism can be a consequence of higher prolactin production that can block the secretion and action of gonadotropins, being the main cause of the changes observed

in vitro differentiation of human endometrial stromal cells: effect of transforming growth factor B 1 on prolactin secretion

OBJECTIVE: To investigate the role of Transforming Growth Factor beta 1 on differentiation of human endometrial stromal cells. STUDY DESIGN: A prospective study. MATERIAL AND METHODS: Human endometrial cells obtained from 9 women were cultured in DMEM-HAMs F12 media to adequate cell confluence and then the flasks were cultured in the presence and absence of TGF b 1. The influence of TGF beta 1 were measured by prolactin production expressed as nanograms of prolactin/mg of total DNA in cells measured by diphenylamine reaction. The levels of prolactin in the culture medium with and without TGF beta 1 were 0.16 +/- 0.27 ng/microgram DNA/day and 0.24 +/- 0.41 ng/microgram DNA/day respectively. There was no significant difference between groups. There is no direct effect of TGF beta 1 on differentiation of human endometrial stromal cells. However it may involve in more complex relationship in this process

La prolactina y su participación en la regulación de la función ovárica / Prolactin and its participation in ovarian function regulation

La prolactina es una de las hormonas más versátiles concocidas, con funciones moduladoras en procesos diversos tales como los mecanismos inmunológicos y los fenómenos reproductivos. Históricamente, se han relacionado la prolactina y el ovario desde la perspectiva de la hiperprolactinemia como un trastorno que afecta el comportamiento del eje hipotálamo-hipófiso-ovárico, sin embargo existen suficientes evidencias que apuntan hacia un control directo de la prolactina sobre la función ovárica y recientemente se ha identificado el aparato sintético de la prolactina localizado en las células de la granulosa de los folículos ováricos, lo que sugiere la existencia de un mecanismo autocrino de la prolactina en el control intraovárico. Es importante establecer las relaciones entre la prolactina en el control intraovárico. Es importante establecer las relaciones entre la prolactina hipofisaria y los péptidos semejantes a ella de origen endotelial, linfocitario y ovárico en diferentes condiciones fisiológicas y patológicas del individuo

Comportamento da PRL endometrial em mulheres hiper e normoprolactinêmicas / Endometrial Prolactin in hyper and normoprolactinemic women

OBJETIVOS: Verificar o comportamento da Prolactine (PRL) endometrial. CASUíSTICA E MÉTODOS: foram estudadas 40 mulheres, com média etária de 28,3 anos e selecionadas por apresentarem os seguintes sintomas: alteraçäo do ciclo menstrual e/ou esterilidade e/ou galactorréia. As pacientes foram divididas em dois grupos: Grupo A - dezenove mulheres hiperprolactinêmicas e Grupo B - vinte e uma mulheres normoprolactinêmicas. Exames laboratoriais foram realizados na fase folicular inicial (do terceiro ao nono dia), fase lútea inicial (do 15º ao 21º dia) e fase lútea tardia (do 22º ao 29º dia), nas pacientes que menstruavam (1ª, 2ª e 3ª amostras, respectivamente) e, nas que näo menstruam, no primeiro, 14º e 21º dia da consulta (1ª, 2ª e 3ª amostras, respectivamente). Na 1ª amostra, foram dosados LH, FSH, PRL e estradiol e nas 2ª e 3ª amostras a PRL e a progesterona. Todas as mulheres foram submetidas a duas biópsias de endométrio para a verificaçäo do padräo menstrual, dateamento e detecçäo imuno-histoquímica da PRL endometrial. Essas biópsias foram realizadas na 2ª e 3ª amostras. RESULTADOS: expressos em percentuais da PRL endometrial mostraram: as médias dos percentuais da PRL endometrial foram maiores na fase lútea inicial nas mulheres hiperprolactinêmicas e normoprolactinêmicas. CONCLUSöES: A PRL sérica näo se correlaciona com a endometrial e a síntese da PRL endometrial está em relaçäo direta a diferenciaçäo das células estromais, induzida pela progesterona, em endométrio decidualizado.

Neuroendocrine mechanisms of lactational infertility in women

The current knowledge on the mechanisms of lactational infertility, discussed during a symposium of investigators in this subject, is reviewed. Three periods of lactation are examined: the first weeks postpartum, the period of extended lactational amenorrhea and the recovery of ovarian function. In the first postpartum weeks the inhibition of ovarian function is accounted by diminished pituitary response to GnRH, since exogenous GnRH fails to elicit a LH increase. Suckling can extend the period of ovarian inhibition for weeks, months or years, although it does not fully suppress pulsatile secretion of LH beyond the first weeks. Extended lactational amenorrhea is associated with low LH plasma levels, a great PRL increase in response to suckling, low basal E2 levels and a suppression of estrogen positive feedback. Decreased immunoreactive LH levels may result from partial suppression of the LH pulse generator and a smaller mass of GnRH released in each burst. The role of neurotransmitters, PRL and ovarian factors is discussed. After the recovery of ovulatory cycles suckling still has a residual infertility effect, associated to inadequate luteal function. The sources of variation among women and populations were recognized. Areas in which research is needed to improve the understanding of the mechanisms that sustain lactational amenorrhea are suggested

Fisiología ovárica postparto: gonadotropinas hipofisarias, estradiol y prolactina durante 12 meses a la resolución del embarazo / Post-partum ovarian physiology. Hypophysial gonadotropins, estradiol and prolactin during 12 months at pregnancy resolution

Se realizó un seguimiento por doce meses en una cohorte de 17 mujeres, a partir de la resolución del embarazo para tratar de valorar la asociación hiperprolactinemia lactacional/hormonas estimulante de folículo (FSH)/hormona luteinizante (LH) y reinicio de la actividad ovárica. El estudio se dividió en dos fases: Lactancia (Lac) y post-lactancia (post-Lac). En ambas etapas se tomaron muestras de sangre venosa periférica cada semana hasta la semana 52, para cuantificar: FSH, LH, prolactina (PRL) y estradiol (E-2). Durante Lac, las concentraciones periféricas del PRL, fueron significativamente mayores a Post-Lac; observándose una relación inversamente proporcional E-2/PRL a lo largo del seguimiento. No existieron cambios significativos para LH y FSH en ambas fases y las cifras se mantuvieron dentro de niveles fisiológicos. Al compararlas con un sujeto control no mostraron diferencias. Los coeficientes de correlación revelaron una asociación negativa entre PRL y los días que transcurrieron al postparto y positiva para E-2. Los hallazgos indican una función folicular, aparentemente independiente del estímulo gonadotrópico hipofisario

Electroconvulsive therapy in Parkinson's disease

Para evaluar el efecto de la terapia electroconvulsivante (TEC) en pacientes con enfermedad de parkinson, Nosotros condujimos un estudio abierto con un curso de siete días de TEC en seis pacientes con enfermedades de parkinson idiopática. El deterioro motor mejoró en todos los casos durante TEC. Esta mejoría fue sostenida en tres pacientes después de 30 días, y persistió hasta el día 60 en un paciente; los registros de depresión mejoraron en cuatro pacientes y los niveles séricos de prolactina estuvieron elevados con cinco pacientes durante la TEC, disminuyendo establemente después. La respuesta a la TEC observada en las valoraciones motoras, congnoscitivas o afectivas pereció que era independiente una de otra. La mejor respuesta en la ejecución motora se observó en aquellos pacientes con una evolución más corta de la enfermedad y etapas más bajas de discapacidad. El método de TEC utilizado en este estudio fue seguro y evitó la apnea o las contracciones musculares. Nosotros concluímos que la electroterapia perece que induce una respuesta favorable aunque afímera en la enfermedad de parkinson. Sin embargo, se deben de hacer estudios controlados a largo plazo. Otros métodos de electroestimulación más selectivos de vías dopaminérgicas se deben de investigar.

Serum gonadotropins, testosterone and prolactin in azoospermic men in relation to the histopathological changes

Serum follicle stimulating hormone [FSH], luteinizing hormone [LH], testosterone and prolactin levels in relation to histopathological appearance were studied in 32 azoospermic men. Histologically, they were classified into four groups; normal[25%], sertoli-cell-only syndrome [28.1%], maturation arrest [25%] and focal tubular atrophy [21.8%]. In azoospermic men with normal histological findings, gonadotropins and testosterone levels were within the normal values. In other groups associated with histological changes, gonadotropins were significantly raised. Testosterone had a significant lower levels than normal in cases of maturation arrest. Prolactin levels were normal in all azoospermic men. These findings suggested the importance of hormonal determination for evaluation and management of male infertility

Fisiologia de la prolactina / Physiology of prolactin

Descripcion de la secrecion y sintesis, variaciones fisiologicas, concentraciones y receptores de la prolactina