Serum LH levels in prepubertal female pigs chronically treated with synthetic luteinizing hormone-releasing hormone-follicle stimulating hormone-releasing hormone (LH-RH-FSH-RH).

Abstract

A double—antibody radioimmunoassay utilizing a heterologous system specific for porcine luteinizing hormone (PLH) has been developed with rabbit antibovine LH serum as a first antibody. Porcine LH (LER-786-3) was used for iodination and as a reference standard. Reliable estimates of LH could be obtained in 200 pi of serum from immature pigs at any time. Porcine follicle-stimulating hormone (FSH), porcine thyroid- stimulating hormone, porcine adrenocorticotropic hormone or serum components per se did not affect measurements of LH. Ten prepubertal female pigs (mean wt 12.8 kg) were assigned randomly in equal numbers to a treated or control group. Treatment consisted of 16 im injections of 25 ng of pure synthetic LH and FSH releasing hormone (LH-RH/FSH-RH) in one ml of acidified saline or acidified saline only at 6–hr intervals over a period of 96 hr for treated and control animals respectively. Blood samples were collected via indwelling jugular catheters, at various times following each injection. Serum LH...