The oocyte requires a vast supply of energy after fertilization to support critical events such as spindle formation, chromatid separation, and cell division. Until blastocyst implantation, the developing zygote is dependent on the existing pool of mitochondria. That pool size within each cell decreases with each cell division. Mitochondria obtained from oocytes of women of advanced reproductive age harbor DNA deletions and nucleotide variations that impair function. The combination of lower number and increased frequency of mutations and deletions may result in inadequate mitochondrial activity necessary for continued embryo development and cause pregnancy failure. Previous reports suggested that mitochondrial activity within oocytes may be supplemented by donor cytoplasmic transfer at the time of intracytoplasmic sperm injection (ICSI). Those reports showed success; however, safety concerns arose due to the potential of two distinct populations of mitochondrial genomes in the offspring. Mitochondrial augmentation of oocytes is now reconsidered in light of our current understanding of mitochondrial function and the publication of a number of animal studies. With a better understanding of the role of this organelle in oocytes immediately after fertilization, blastocyst and offspring, mitochondrial augmentation may be reconsidered as a method to improve oocyte quality.

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We have genetically engineered a cell line, and developed a reproducible process, for the expression and purification of biologically active recombinant human thyroid stimulating hormone (rhTSH).rhTSH was expressed by co-transfecting a human alpha-subunit cDNA with a human beta-subunit partial genomic clone into Chinese Hamster Ovary (CHO) cells. Stable transfectants which expressed high levels of rhTSH were selected, and subsequently cultured on microcarrier beads. The rhTSH-containing media, produced under serum-free conditions, was clarified and purified by a combination of ion exchange, dye and gel filtration chromatographies. Individual step recoveries were greater than 90% with the exception of a very conservative pooling of the final gel filtration step (78% recovery) that resulted in a cumulative yield of 54% for the purification process. Purity of the final bulk material was judged to be > 99% by SDS polyacrylamide gel electrophoresis (SDS-PAGE), reverse phase HPLC, and size exclusion chromatography. Initial characterization of the oligosaccharide composition indicated the presence of partially sialylated bi- and triantenary complex oligosaccharides. Purified rhTSH was active in a thyroid membrane bioactivity assay with a specific activity of 8.2 IU/mg. The in vivo activity of rhTSH in cynomolgus monkeys appeared to be equal to or greater than that reported for bovine TSH (bTSH) in human subjects. The rapid clearance phase half-life of rhTSH was approximately 35 minutes while the post-distribution phase half life was approximately 9.8 hours. Furthermore, the monkeys showed cumulative increases in minimum plasma rhTSH levels when given three daily intramuscular (IM) rhTSH injections; a phenomenon not observed when bTSH had been administered to humans. The rhTSH showed no evidence of toxic or adverse effects when administered at doses up to 7.2 IU/kg and 0.52 IU/kg in rat and monkey, respectively. These are 50X and 4X multiples of the bTSH doses of 0.143 IU/kg (10 IU/70kg) previously administered to humans.

FSH bioactivity was measured by means of FSH-dependent aromatase activity (conversion of androgen substrate to estradiol). Assay sensitivity was optimized by the use of immature (7-10 days old) rats as Sertoli cell donors, serum-free medium for incubation, phosphodiesterase inhibitor (methylisobutylxanthinine), serial dilution of FSH in medium containing 1% BSA, delayed addition of FSH for 72 h after cell plating, and 19-hydroxyandrostenedione (2.5 X 10(-6) M) as the aromatizable androgen substrate. The method consisted of subjecting the decapsulated immature rat testes to a 2-step collagenase dispersion, plating the cells in medium [Dulbecco's Modified Eagle's Medium-Ham's F-10 (1:1)] containing growth factors and methylisobutylxanthinine for 72 h, adding increasing doses of FSH to the standard curve or small volumes of serum to the test vials as well as 19-hydroxyandrostenedione for 24 h, and measuring estradiol by RIA in dilutions of the medium. Using NIAMDD human (h) FSH-2 as the bioassay standard, the useful range of the assay was 0.01-5.0 ng/ml. Specificity was determined by the addition of graded doses of hLH, hTSH, ACTH, hGH, hPRL, and hCG. The minor degree of FSH bioactivity observed in a few hormone preparations was accounted for by the degree of FSH contamination in them. Mean intra- and interassay coefficients of variation were 9% and 11%, and the index of precision was 0.049. This bioassay was used to determine the bioactive FSH content of pituitary extracts, tissue culture media, elutions from columns, and isoelectrically focused samples. More importantly, small quantities of human sera gave responses parallel to the standard curve in a minimum of two dilutions. The bio- to immunoreactive ratios, expressed as the mean +/- SEM (NIAMDD-hFSH-2), were 0.66 +/- 0.2 in boys (n = 6), 0.78 +/- 0.2 in pubertal girls (n = 6), 1.18 +/- 0.2 in men (n = 13), 1.24 +/- 0.1 in postmenopausal women (n = 30), 1.94 +/- 0.3 in the follicular phase (n = 19), 6.2 +/- 1.4 in the ovulatory phase (n = 19), and 1.6 +/- 0.4 in the luteal phase (n = 19) of the normal menstrual cycle. These results indicate that the bio- to immunoreactive hFSH ratio in the circulation, is dependent upon the hormonal milieu of the subject.