Increase of nuclear bodies in bovine luteal cells after treatment with human chorionic gonadotropin.

Nuclear bodies, which are dynamic components of nuclei indicating the level of nuclear activation and cellular transcriptional and translational events, were found in small numbers (2 to 4 nuclear profiles per 150 examined) in control luteal tissue. The number of nuclear bodies, however, greatly increased after incubation with increasing concentrations of human chorionic gonadotropin (hCG). Either one simple or one complex, but very rarely two or more nuclear bodies per nuclear profile, were found in response to hCG. The nuclear bodies increased by 1 h of incubation with hCG at 38 degrees C (p less than 0.01), which further increased by 2 h, remained elevated until 8 h (p less than 0.01), and then returned to control levels by 12 h, Thirty to forty percent of the nuclear bodies that increased in response to hCG were complex nuclear bodies; these are larger than simple nuclear bodies, and contain a fibrillar capsule surrounding the electron-dense or granular core of tightly packed osmophilic material. While hCG increased the number of nuclear bodies similarly at 22 degrees C and 38 degrees C, it had no effect at 4 degrees C. hCG had no effect on nuclear bodies in luteal fibroblasts and endothelial cells or in bovine liver or kidney cells, suggesting that the effect of hCG was cell- and tissue-specific. High concentrations of human prolactin (hPRL), human follicle-stimulating hormone (hFSH), or prostaglandin (PG) E1 or PGF2 alpha had no effect on nuclear bodies in luteal cells, suggesting that the hCG effect was hormone-specific.(ABSTRACT TRUNCATED AT 250 WORDS)