Fertility induction associated with improved peripheral reproductive parameters in male Prop1df/df mice subjected to GH and levothyroxine replacement.

Treated Prop1df/df mice developed sexual maturation approximately 2 weeks later than wild-type mice.

• Male Prop1df/df mice received daily intraperitoneal injections of recombinant human GH and levothyroxine three times weekly beginning at 30 days of age for 60 days.
• Sexual maturation timing was compared among three groups: wild-type (Prop+/+), untreated Prop1df/df, and treated Prop1df/df.
• The treated Prop1df/df group achieved sexual maturation, but with an approximate 2-week delay compared to wild-type siblings.

GH and levothyroxine replacement induced complete spermatogenesis and increased testicular weight in Prop1df/df mice.

• Treated Prop1df/df mice showed an increase in testicular weight relative to untreated Prop1df/df mice.
• Complete spermatogenesis was achieved in the treated group.
• Untreated Prop1df/df mice did not develop sexual maturation during the study period in most cases.

GH and levothyroxine replacement enhanced LH and FSH expression in the pituitary of Prop1df/df mice.

• Treated Prop1df/df mice showed enhanced LH and FSH expression compared to untreated counterparts.
• Untreated Prop1df/df mice had low FSH expression.
• Pituitary hormone expression levels were among the key reproductive parameters characterized in this study.

Untreated Prop1df/df mice failed to produce offspring and largely did not achieve sexual maturation during the study period.

• The untreated Prop1df/df group had no offspring recorded during the study.
• Most animals in the untreated group did not develop sexual maturation during the 60-day treatment observation period.
• Low FSH expression was observed in untreated Prop1df/df mice, consistent with gonadotropin deficiency due to Prop1 mutation.

Prop1df/df (Ames dwarf) mice were used as a model of combined GH and thyroid hormone deficiency to study reproductive development.

• Ames dwarf mice carry the Prop1df/df mutation, which results in deficiencies of GH, prolactin, and TSH due to pituitary dysfunction.
• Animals were started on treatment at 30 days of age, and the treatment duration was 60 days.
• Recombinant human GH was administered via daily intraperitoneal injection, and levothyroxine was given three times weekly.
• Reproductive anatomy parameters and pituitary hormone expression levels were characterized across the three experimental groups.