Evaluation of in Vitro Culture Conditions to Demonstrate Pregnancy-Dependent Changes in Luteal Function in the Pig1

Więsak, Teresa; Hardin, R. T.; Foxcroft, G. R.

doi:10.1095/biolreprod51.2.254

Cited by 7 publications

(2 citation statements)

References 42 publications

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“…Labelled hormones: (1,2,6,7-3 H) progesterone, (1,2,6,7 (N)-3 H) androst-4-ene-3,17 dione, (1,2,6,7-3 H) testosterone, (2,4,6,7-3 H) oestrone, and (2,4,6,7-3 H) oestradiol were from Amersham, UK. Anti-results reported by Wiesak et al [52] and Baranao and Hammond [5]. Granulosa cells (10 6 viable cells/well) were cultured in 24-well culture plates for 24 h in serum free conditions in a humidified incubator (37 °C) gassed with 95% air and 5% CO 2 .…”

Section: Methodsmentioning

confidence: 99%

The physiological role of ?-endorphin in porcine ovarian follicles

et al. 2000

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-β-Endorphin-like immunoreactivity (β-END-LI) was measured by radioimmunoassay in porcine ovarian follicular fluid (FF) from small, medium and large follicles throughout the oestrous cycle. The concentration of β-END-LI in FF from small follicles collected on days 1-5 of the cycle was at least tenfold higher than in the fluid from any other follicles independently from their size and the period of the cycle. The level of β-END-LI in small follicles on days 6-10 was drastically decreased. Subsequently, on days 11-16 its concentration was enhanced and reduced again in preovulatory period of the cycle. Concentrations of β-END-LI in FF from medium follicles were relatively equal throughout the cycle (days 6-21). No significant differences in β-END-LI levels were found between small, medium and large follicles from days 17-21. However, β-END-LI concentrations in medium follicles on days 11-13 and 14-16 were statistically lower than those in small follicles. Moreover, the effects of FSH, prolactin (PRL), progesterone (P 4 ), testosterone (T) and 17 β-oestradiol (E 2 ) on β-END-LI release by granulosa cells (GCs) from large follicles and, on the other hand, the effects of the opioid agonist FK 33-824 alone or in combination with FSH, PRL or naloxone (NAL) on follicular steroidogenesis were studied. FSH drastically increased β-END-LI output in a dose-dependent fashion. This stimulatory effect of the gonadotrophin was inhibited by the highest dose of P 4 (10 -5 M). The effect of PRL and the steroids added to the cultures on β-END-LI release was negligible. FSH-or PRL-induced P 4 secretion by GCs was essentially abolished by both FK 33-824 and NAL. However, androstenedione (A 4 ) and testosterone output by the cells was greatly potentiated by FK 33-824. In the presence of NAL, FSH or PRL, A 4 release stimulated by FK 33-824 was suppressed to the basal level. Secretion of E 2 was completely free from the influence of FK 33-824 or NAL; only oestrone (E 1 ) output was modulated by them in cultures where FSH or PRL was present. In conclusion, FSH appears to be the key regulator of β-END-LI secretion by porcine granulosa cells. Moreover, steroidogenesis in pig granulosa cells is modulated by opioid peptides acting both alone and by way of interaction with FSH or PRL.opioid peptides / β-endorphin / porcine granulosa cells / steroid secretion Reprod. Nutr. Dev. 40 (2000) 63-75 63

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Section: Methodsmentioning

confidence: 99%

The physiological role of ?-endorphin in porcine ovarian follicles

et al. 2000

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“…Samples in four tubes were immediately frozen for assay of tissue progesterone content before culture (T0 P4). Minced tissue in the remaining tubes was cultured in 2 ml of Eagles minimum essential medium (MEM; Sigma) containing a range of LH concentrations (0, 0.1, 1, 10, and 100 ng pLH/ml), which was previously shown in our laboratory to be effective in assessing luteal cell responsiveness to LH stimulation [29], with four replicates per dose. Luteinizing hormone activity in the media were confirmed by radioimmunoassay (RIA).…”

Section: Incubationsmentioning

confidence: 99%

Feed Restriction and Insulin Treatment Affect Subsequent Luteal Function in the Immediate Postovulatory Period in Pigs: Progesterone Production In Vitro and Messenger Ribonucleic Acid Expression for Key Steroidogenic Enzymes1

Mao¹,

Treacy²,

Almeida³

et al. 2001

Biology of Reproduction

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Progesterone production and release in vitro, and mRNA expression for key steroidogenic enzymes, were studied in luteal tissue recovered in the immediate postovulatory period from cyclic gilts allocated to one of three treatments: moderate feed restriction during the first (RH) or second week of the estrous cycle, with (HR+I) or without (HR) concomitant injections of long-acting insulin. Time of feed restriction affected neither progesterone production or release, nor mRNA expression for several key steroidogenic enzymes. However, luteal tissue from RH but not from HR gilts responded to LH stimulation by increasing progesterone production and release (P: < 0.05). Insulin treatment increased progesterone production and release, restored luteal tissue responsiveness to LH, up-regulated steroidogenic enzyme mRNA expression, and down-regulated the tissue inhibitor of metalloproteinase-I mRNA expression in HR+I compared with HR gilts (P: < 0.05). In vitro progesterone production and gene expression were affected by time of tissue collection after ovulation in RH and HR gilts but not in HR+I gilts, and were correlated with temporal changes in oviductal and peripheral plasma progesterone concentrations. Inherent differences in luteal function therefore appear to mediate latent effects of nutrition and insulin treatment on circulating progesterone concentrations in the critical postovulatory period in gilts.

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