Recombinant gonadotrophins

Gonadotrophins are now also produced by recombinant DNA technology. The genes, or cDNAs coding for gonadotrophins from several species, have been identified and expressed in various... 

Table 11.10 Recombinant gonadotrophins now approved for general medical use in the EU and/or the USA...

The causes of variability of superovulatory responses are complex and not fully understood. The general health of the animal, as well as its characteristic reproductive physiology, is important. The exact composition of the gonadotrophin preparations administered and the exact administration protocol also influence the outcome. The variability of FSH LH ratios in many p-FSH preparations can affect the results obtained, with the most consistent superovulatory responses being observed when FSH preparations exhibiting low LH activity are used. The availability of recombinant FSH and LH will overcome these difficulties at least. 

Al-Inany, H., Aboulghar, M.A., Mansour, R.T., and Proctor, M. 2005. Recombinant versus urinary gonadotrophins for triggering ovulation in assisted conception. Human Reproduction 20(8), 2061-2073. 

Table 1.10. Some pharmaceutical substances originally isolated from animal sources. While some are still produced by direct extraction from the native source, others are now also produced by direct chemical synthesis (e.g. peptides and some steroids), or by recombinant DNA technology (most of the pol5 peptide products). Abbreviations hGH = human growth hormone FSH=follicle stimulating hormone hCG=human chorionic gonadotrophin HSA=human serum albumin HBsAg=hepatitis B surface antigen...

The functional effects of glycosylation take on added significance in the context of producing gonadotrophins by recombinant means. As subsequently discussed, several are now produced for clinical application in recombinant (animal cell line) systems. While the glycosylation patterns observed on the recombinant molecules can vary somewhat in composition from those associated with the native hormone, these slight differences bear no negative influence upon their clinical applicability. 

The recombinant production of FSH and LH also obviously facilitates the generation of a pure preparation of any one gonadotrophin, without contamination by a second gonadotrophin. Such preparations continue to facilitate a greater understanding of the precise role each gonadotrophin plays in reproductive function. 

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