Scientific Tracks Abstracts: J Neurol Neurophysiol
Manipulation of gonadotropin hormones (luteinizing (LH) and follicle stimulating hormones (FSH)) in ewes in nonbreading
season is a major challenge to the scientific community. We hypothesized that sustained delivery of progesterone
and estrogens by means of Tricalcium-Phosphate-Lysine delivery systems (TCPL) can suppress the rise in LH and FSH levels
and ultimately induce cycling activities. The specific objective of this study was to design an implantable TCPL system capable
of delivering progesterone (P) for about two weeks and Estradiol (E) in a short burst that mimics the ovulatory surge in adult
ewes. TCPL implants were fabricated in four different sizes (1.5, 2.3, 3.5, or 5.6 cm) using four different ceramic compositions
and impregnated with P (20-45%) and E (4-16%). Surgical aseptic techniques were employed following standard approved lab
protocols. Blood samples were collected daily and anlyzied for P, E, LH and FSH levels. X-ray procedure was performed twice
a week to assure the intactness of the devices.
The results of this study revealed:
• TCPL were cable of delivering P and E at levels that mimic the estrus cycle
• Remarkable reduction of LH and FSH levels in all experimental animals compared to sham operated group. Overall
conclusion, results of this study demonstrated that the anterior pituitary gonadotropin hormones can be regulated through
sustained delivery of reproductive hormones.