Effects of phytoestrogens on testosterone secretion by Leydig cells from Biłgoraj ganders (Anser anser)

Abstract

The aim of this study was to examine ganders at different stages of the reproductive season and the effect of: (1) diets with high phytoestrogen content and (2) in vitro phytoestrogen treatment on testosterone secretion by isolated Leydig cells. Thirty-six male Biłgoraj geese were fed control diets with low phytoestrogen content (containing grass meal) and diets with high phytoestrogens (containing alfalfa meal and soy). Testes were obtained from both groups of ganders at three different times of the breeding season: peak of reproductive activity (March), second half of reproductive activity (May) and beginning of photorefractoriness (July). Isolated Leydig cells were incubated with LH as well as genistein, daidzein, equol and coumestrol and the concentration of testosterone in the medium was determined by radioimmunoassay. The mean weight of testes from ganders in May and July decreased relative to their weights in March, but no significant differences among experimental groups were noted. No differences were observed in basal and LH-stimulated testosterone secretion by Leydig cells of ganders fed the control diets and the diets with higher phytoestrogen content. In July, LH did not stimulate testosterone secretion in either group. In vitro treatment with genistein, daidzein and equol (5 and 50 microM) inhibited basal and LH-stimulated testosterone production by Leydig cells from both groups. Coumestrol (5 and 50 microM) inhibited basal testosterone secretion only in March in the control group. Dietary exposure to phytoestrogens had a slight effect on in vitro testicular secretion in ganders. In vitro treatment with phytoestrogen inhibited testosterone production by Leydig cells. Genistein showed the strongest effect and coumestrol had the weakest influence on testicular secretion.

Seasonal changes in the expression of the androgen receptor in the testes of the domestic goose (Anser anser f. domestica)

“…Histological and morphometric analyses revealed that gander testes undergo marked structural seasonal changes as it has been described in Bilgoraj goose (Anser anser) and Canadian goose (Branta canadensis) [28,31,32] and other bird species [1,20,25,42]. Interestingly, structural changes in testicular tissue in the sexual reactivation phase remain weakly researched, especially in geese.…”

Modified expression of aryl hydrocarbon receptor-related genes by deoxymiroestrol, a phytoestrogen, in mouse hepatocytes in primary culture

“…The activated AhR forms a heterodimer with AhR nuclear translocator protein (ARNT) and then binds to a xenobiotic responsive element in the promoter region of many genes of the so-called AhR gene battery for induction of transcription (Nebert et al, 2000). Phytoestrogens are natural compounds affecting sexual behavior as well as morphology and function of male and female reproductive organs (Opalka et al, 2006). Chansakaow et al (2000) identified deoxymiroestrol (DM) as the active component that found in Pueraria candollei tuber, a traditional Thai medicine.…”

Oestrogen receptor α and β mRNA expression in testis of ganders fed diets containing different levels of phytoestrogens

“…Levels of total phytoestrogens in C and P diets were 15.40-40.44 and 118.54-151.19 µg/g, respectively. Detailed diets compositions and concentrations of phytoestrogens were previously described (Opałka et al, 2006).…”

“…Animals were kept and fed as previously described (Opałka et al, 2006). Briefl y, 1-day-old (April/May hatched) Biłgoraj male goslings (Anser anser) were divided into a control group fed diets containing low levels of phytoestrogens (C), based on grass meal and a group fed diets containing with higher levels of phytoestrogens (P), based on lucerne meal and soyabean meal.…”

“…Although phytoestrogens exhibit nonsteroidal, diphenolic structure they can interact with oestrogen receptors and in consequence infl uence animal reproduction (Adams, 1995) including bird (Leopold et al, 1976;Lien et al, 1987). In our previous study, we noted that phytoestrogens inhibited in vitro secretion of testosterone by gander testicular cells (Opałka et al, 2006).…”