Effects of treatment of neonatal XXXX with highly purified FSH alone and in combination with LH on testicular function and endogenous hormone levels at various ages.

@entity35 @entity1 @entity251
Factors which play a role in the regulation of testicular size in @entity35 were investigated using neonatal animals treated with exogenous gonadotrophins for 2 or 3 weeks, starting on the day after birth. Effects on testis weight and various aspects of the pituitary-testicular axis were evaluated up to the age of 9 weeks. Daily treatment with @entity1 FSH (Metrodin; 0.15 U/g body wt) for 2 or 3 weeks, starting on the first day or 1 week after birth, resulted in enlargement of the testes, increased testicular content of inhibin and a suppression of pituitary and plasma FSH. The relative increase of testis weight decreased after cessation of treatment. Injections of @entity1 FSH combined with administration of @entity1 LH (Pergonal) for 3 weeks, starting on the first day after birth, resulted in larger testes immediately after treatment. In addition, an increased amount of interstitial tissue was observed in these animals. Pituitary and plasma FSH and LH were suppressed after this treatment, while the growth of the accessory sex organs was significantly stimulated. In animals treated with @entity1 FSH during the first 2 or 3 weeks of life, levels of @entity35 FSH in blood samples collected at weekly intervals were significantly suppressed until the animals were killed at the age of 9 weeks. In the animals treated with @entity1 FSH and @entity1 LH, both FSH and @entity251 concentrations were significantly lower than those in control animals between the ages of 4 and 9 weeks. At the age of 9 weeks testicular weights were still higher than those in control animals after these treatments.(ABSTRACT TRUNCATED AT 250 WORDS)
