The effects of the age of intracerebroventricular grafts of normal preoptic area tissue upon pituitary and gonadal function in hypogonadal (HPG) mice.
Hypogonadal mice are deficient in the hypothalamic gonadotrophic hormone releasing hormone and as a consequence postnatal testicular development does not occur. Grafting preoptic area tissue from normal mice directly into the hypogonadal third ventricle dramatically reverses the hypogonadism; however, the age of the grafted preoptic area tissue is crucial to the survival and function of the graft. Grafting embryonic tissue (E16-18) resulted in 69% of the hypogonadal mice increasing testis weight some sevenfold within 30 days (5.6 to 35 mg). Postnatal day 1 (P1) tissue grafts elicited a similar rise in testis weight in 77% of recipients, whereas P5 tissue was only successful in 22% of cases. In this experimental group, however, testis weight also increased sevenfold compared with hypogonadal untreated mice. Stimulation of testicular growth in the E16-18 and P1 experimental groups was accompanied by an increase in pituitary gonadotrophic hormone content. P10 tissue did not stimulate testis growth nor was pituitary gonadotrophic hormone control elevated and the majority of grafts failed to survive over the 30 day period of the experiment. The present study has shown that the age of grafted tissue is critical in the restoration of physiological function in hypogonadal mice, and that gonadotrophic hormone releasing hormone neurons from E16-18, P1 and P5 preoptic area grafts that survive the 30 day period of the experiment and whose axons reach the median eminence portal vessels are equipotent in stimulating pituitary gonadotrophin synthesis and secretion.
D000367:Age Factors; D000818:Animals; D002552:Cerebral Ventricles / Q000601:surgery; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D007006:Hypogonadism / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009929:Organ Size; D010902:Pituitary Gland / Q000378:metabolism*; D011301:Preoptic Area / Q000637:transplantation*; D012669:Seminal Vesicles / Q000473:pathology; D013737:Testis / Q000473:pathology*; D014019:Tissue Donors
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone