Recombinant forms of rat and human luteinizing hormone and follicle-stimulating hormone; comparison of functions in vitro and in vivo.

We have previously described the preparation, purification and partial characterization of recombinant (rec) forms of rat luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In the present study, the special functional features of these hormones were studied further, in vitro and in vivo, and compared with human recLH and recFSH, as well as with human urinary choriongonadotropin (hCG) and rat pituitary LH (NIDDK-RP3). In radioreceptor assay, the affinity of hCG binding to rat testis membranes was 5-fold higher than that of human recLH and 100-fold higher than that of rat recLH.

Dose and time relationships of intravenously injected rat recombinant luteinizing hormone and testicular testosterone secretion in the male Rat.

The ability of hCG and LH to induce testosterone (T) secretion by Leydig cells is well documented. However, the influence of the pulsatile nature of LH secretion, with varying frequency and amplitude, on T production in vivo is less clear. In our earlier studies on the relationship between pulsatile LH release and T secretion in adult male rats, no simple causality was observed.

Recombinant rat luteinizing hormone; production by Chinese hamster ovary cells, purification and functional characterization.

Rat recombinant (rec) luteinizing hormone (LH) was produced in Chinese hamster ovary (CHO) cells, to enable studies on LH physiology in this species with homologous hormone. The synthesized hormone was purified, and characterized physico-chemically and biologically in comparison with highly purified preparations of rat pituitary (pit) LH (NIDDK-rLH-I-7 and I-9) and to highly purified urinary (NIH, CR-121) and rec forms of human chorionic gonadotropin (hCG). The 33 kD molecular mass of rat recLH, as determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot, was comparable with the 32 kD size of pitLH.

Recombinant rat follicle-stimulating hormone; production by Chinese hamster ovary cells, purification and functional characterization.

In order to obtain homologous follicle-stimulating hormone (FSH) for in vivo and in vitro studies in the rat, rat recombinant (rec) FSH was produced in Chinese Hamster Ovary (CHO) cells. The synthesized rat recFSH was purified and subjected to physico-chemical and biological characterization. including a comparison with two rat pituitary (pit) and reference preparations (NIDDK-rFSH I-8 and NIDDK-rFSH-RP2) as well as with human recFSH (Org 32489).