Summary Postovulatory and middle luteal phase corpora lutea of pig ovaries were cultured as monolayers with the addition of three different fractions of stallion semen. The semen was collected from an Anglo‐Arab male and the entire ejaculate was separated into three fractions from consecutive parts of the reproductive tract. The third fraction exerted a luteotropic effect on corpora lutea cells collected at the early and middle luteal phases of the cycle. These results suggest that the third seminal fraction contained PGE. The cells of both types of corpus luteum showed an increase of enzyme activity and of progesterone secretion. Zusammenfassung Direkter Einfluß von Hengstsamen auf die Progesteronsekretion von kultivierten Gelbkörperzellen Unter Zugabe von drei verschiedenen Fraktionen von Hengstsamen wurden Gelbkörperzellen von Schweinen der postovulatorischen und mittleren Lutealphase als Monolayer gezüchtet. Das Sperma wurde von einem Angloaraber‐Hengst gewonnen, und zwar in Form von drei Fraktionen aus den verschiedenen Teilen des Genitaltraktes (1. Fraktion: Nebenhodenschwanz und Samenblasen, 2. Fraktion: Cowpersche Dröse und Prostata, 3. Fraktion: restliches Sekretgemisch der akzessorischen Drüsen). Die 3. Fraktion übte auf die Gelbkörperzellen, welche aus der frühen und mittleren Lutealphase stammten, einen luteotropen Effekt aus. Die Ergebnisse lassen vermuten, daß die 3. Fraktion Prostaglandin E enthält. Beide Typen der Gelbkörperzellen wiesen eine verstärkte Enzymaktivität und Progesteronsekretion auf. Résumé Influence directe du sperme d'étalon sur la sécrétion de progestérone des cellules cultivées de corps jaune Des cellules de corps jaune de porcs de la phase de post‐ovulation et de la phase moyenne de lutéinisation ont été cultivées comme «monolayer» avec une adjonction de trois fractions différentes de sperme d'étalon. Le sperme provenait d'un étalon anglo‐arabe et sous la forme de trois fractions de parties différentes du tractus génital (Fraction 1: épididyme et vésicule séminale. Fraction 2: glande de Cowper et prostate. Fraction 3: mélange de sécretion final des glandes accessoires). La troisième fraction a exercé un effet lutéotrope sur les cellules de corps jaune qui prevenaient de la phase précoce et moyenne de lutéinisation. Les résultats permettent de supposer que la troisème fraction contient une prostaglandine E. Les deux types de cellules de corps jaune ont montré une activité enzymatique renforcée et une sécrétion de progestérone. Resumen La influencia directa del semen de caballos enteros sobre la producción de progesterona en células cultivadas de cuerpo amarillo Bajo la adición de tres fracciones diferentes de semen de caballos enteros se cultivaron células de cuerpo amarillo de cerdas de las fases luteínicas postovulatorias y medias como «monocapa». El esperma se obtuvo de un macho angloárabe, a saber en forma de tres fracciones de las partes diversas del tracto genital (1° fracción: epidídimos y vesículas seminales, 2° fracción: glándula de Cowper y próstata, 3° fracción: mezcla de secreción restante de las glándulas accesorias). La fracción 3° ejercía un efecto luteotropo sobre las células de cuerpo amarillo, procedentes de la fase luteínica precoz y media. Los resultados dan pie a sospechar que la fracción 3° contiene prostaglandina E. Ambos tipos de células de cuerpo amarillo mostraban una actividad enzimática y una secreción de progesterona reforzadas.
Insulin-like growth factor-I (IGF-I) is regarded as one of mammary tissue proliferative factors. Insulin-like growth factor binding protein-3 (IGFBP-3) limits the IGF-I binding potential to its receptor. That limits the IGF-I bioavailability. Recently experimental studies indicated that insulin-like growth factor binding proteins (IGFBPs) might have their own biological actions beyond their ability to regulate insulin-like growth factors (IGFs). Our earlier results showed the progesterone-induced rise in hGH and IGF secretion by human breast cancer explants.To determine the ability of progesterone to stimulate simultaneous local IGF-I and IGFBP-3 secretion by non-malignant and malignant mammary tissue collected from different receptor phenotype tumours.Explants from the tumour and surrounding normal non-malignant tissue were obtained during surging. Breast cancer explants were defined as: ER+ PR+; ER-PR-; ER+ PR-; and ER-PR+. Part of the explants was fixed in 10% buffered formalin for steroid receptor determination by immunohistochemistry. Other parts were cut into small pieces, weight and cultured in Parker medium (M199) supplemented with 5% of calf serum at 37 degrees C in an atmosphere containing 5% CO2 for 48 hours in control medium or with the addition of progesterone (10-7 M). Later media were collected for IGF-I and IGFBP-3 concentration analysis.Progesterone increased (p < 0.01) IGFBP-3/IGF-I index in ER(-)PR(-) non-malignant tissue and decreased the IGFBP-3/IGF-I index in ER(-)PR(+), ER(+)PR(-) non-malignant explants. That increased the IGF-I bioavailability. Breast malignant explants showed the progesterone induced IGFBP-3/IGF-I index decrease. The decrease was most evident (p < 0.01) in malignant explants expressing progesterone receptor.Progesterone increased local IGF-I bioavailability in malignant breast tissue. That phenomenon depended on steroid receptor phenotype of breast tissue and was most evident in tissue expressing progesterone receptor. In non-malignant tissue that phenomenon was also found in estrogen receptor expressing tissue. Lack of steroid receptor expression in breast explants reversed that phenomenon.
