Submitted to: Journal of Animal Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/20/2002
Publication Date: 2/1/2003
Citation: WISE, T.H., LUNSTRA, D.D., ROHRER, G.A., FORD, J.J. 2003. RELATIONSHIPS OF TESTICULAR IRON AND FERRITIN CONCENTRATIONS WITH TESTICULAR WEIGHT AND SPERM PRODUCTION IN BOARS. JOURNAL OF ANIMAL SCIENCE. v. 81 (2). p. 503-511. Interpretive Summary: The testis and pituitary make chemicals called hormones, which affect reproduction, growth and health of animals. An understanding of how the testis is regulated and how it interacts with target organs will ultimately lead to improved domestic animal production. Studies were conducted to determine relationships of follicle stimulating hormone on testicular size, color, concentrations of iron and sperm production. As follicle stimulating hormone concentrations increase, testicular size decreases in conjunction with an iron related darkening of the testicular tissues. Immunohistochemistry indicated that the iron binding protein, ferritin was primarily stored in Leydig cells. Such information indicates pituitary hormones play an important role in health and reproduction and understanding regulation may improve animal production.
Technical Abstract: The inverse relationship of testicular size and circulating FSH concentrations has been documented, and accompanying this relationship is the change in color of the parenchymal tissue of the testis. Large testes (300 to 400 g) are pink to light red and small testis (100 g) are dark maroon with color gradations for weights in between. It was hypothesized that the color most likely represented an iron protein. Chromatographic analysis of testicular tissue indicated that the iron (Fe) was associated primarily with ferritin and immunohistochemistry showed that Leydig cells were the primary location of ferritin storage within the testis. Concentrations of Fe and ferritin were higher in small testis and decreased as testis weight increased. As testicular Fe concentrations increased daily sperm production (DSP) and total daily sperm production declined. Genotyping six generations of Meishan × White composite boars (n = 288) for a QTL that is indicative of elevated FSH and small testis in boars indicated that the Meishan genotype had elevated testicular iron concentrations and darker color in conjunction with reduced total DSP. It is not thought the elevated iron concentrations affect testicular weights but are probably a result of elevated FSH and FSH inducement of Fe transport. The storage of Fe in Leydig cells may provide a reservoir of Fe for easy access by Sertoli and germ cells but still provide a degree of protection to germ cells from ionic iron.