ABSTRACT
Insulin-like growth factor-I (IGF-I) has been implicated in a wide variety of physiological processes including ovarian function. To better understand the ovarian role of IGF-I, transgenic mice harbouring a human IGF-I cDNA (hIGF-I) under the control of the mouse LH receptor promoter were generated. Expression of the hIGF-I, determined by Northern blot, was found to occur in the gonad tissues of these transgenic mice. The hIGF-I protein was also detectable by radioimmunoassay in ovarian extracts as well as in the plasma. The fertility of mating transgenic females, as estimated by the number of implantation sites post-coitum, did not appear to be affected. However, transgenic females who failed to mate and produce offspring were found to possess polycystic ovaries. Evaluation of testosterone, estradiol, and LH levels revealed that transgenic animals had significantly elevated circulating levels of testosterone compared to their non-transgenic littermates, while LH levels in transgenic females were significantly lower. Yet, estradiol appeared to be unaffected. These results support the contention that the IGF system plays an important role in ovarian function and that an imbalance in this system may result in ovarian pathology.
Subject(s)
Insulin-Like Growth Factor I/biosynthesis , Ovarian Cysts/etiology , Ovary/metabolism , Animals , Blotting, Northern , Estradiol/blood , Female , Fertility/physiology , Humans , Immunoblotting , Insulin-Like Growth Factor I/genetics , Luteinizing Hormone/blood , Male , Mice , Mice, Transgenic , Ovarian Cysts/pathology , Promoter Regions, Genetic/genetics , Radioimmunoassay , Receptors, LH/genetics , Receptors, LH/metabolism , Testosterone/bloodABSTRACT
Production of foreign proteins in the tissues of transgenic animals represents an efficient and economical method of producing therapeutic and pharmaceutical proteins. In this study, we demonstrate that the mouse P12 gene promoter specific to the male accessory sex gland can be used to generate transgenic mice that express human growth hormone (hGH) in their seminal vesicle epithelium. The hGH is secreted into the ejaculated seminal fluids with the seminal vesicle lumen contents containing concentrations of up to 0.5 mg/ml. As semen is a body fluid that can be collected easily on a continuous basis, the production of transgenic animals expressing pharmaceutical proteins into their seminal fluid could prove to be a viable alternative to use of the mammary gland as a bioreactor.
Subject(s)
Genetic Engineering , Human Growth Hormone/genetics , Human Growth Hormone/metabolism , Semen/metabolism , Seminal Vesicles/metabolism , Animals , Bioreactors , Blotting, Northern , Female , Humans , Immunohistochemistry , Male , Mice , Mice, Transgenic , Promoter Regions, Genetic , TransgenesSubject(s)
Antioxidants/pharmacology , Graft Survival , Intestine, Small/pathology , Ischemia , Lipid Peroxidation/drug effects , Organ Preservation Solutions , Pregnatrienes/pharmacology , Reperfusion Injury/prevention & control , Tissue Preservation/methods , Adenosine , Allopurinol , Animals , Cold Temperature , Edetic Acid , Glutathione , Hypertonic Solutions , Insulin , Male , Raffinose , Rats , Rats, Inbred WF , TemperatureABSTRACT
A nitrate control system has been devised for the maintenance of stable nitrate concentrations throughout fed-batch fermentations of Corynebacterium glutamicum. The feedback control system was based on the use of a nitrate-ion-selective electrode to directly monitor the nitrate levels in the fermentor and an automatic controller to activate a nitrate feed pump. The electrode which was used for controlling the nitrate level was stable through-out the fermentation period. The apparent maximum specific growth rate, biomass production, protein production, biomass yields on glucose and nitrate, and amino acid production were all optimal at approximately 50mM nitrate.