The hypothesis that delivery of thyrotropinreleasing hormone (TRH) in proximity to trigeminal motoneurons (TMNe) can alter craniofacial growth of growing rats was tested by implanting biodegradable polyanhydride microspheres (Mathiowitz et al., 1988; Byrd et al., 1992; Byrd and Hamilton-Byrd, 1994) containing 10% TRH (Bachern, CA) approximately 900 m rostral to left-side TMNu in 10 35-day old male, Sprague-Dawley rats. Blank microsphere (10 rats) and sham (10 rats) procedures were also performed in control rats of identical age; TRH, blank, and sham rats were killed at 14 and 21 days postop for brain histology and dissection. Compared to blanks and shams, TRH rats showed significantly (p<0.05,0.01) larger weights (x±sd g) for the masseter, temporalis, anterior digastric, medial pterygoid, and lateral pterygoid muscles; TRH rats also had alterations of the facial skeleton and TMJ region with longer implant-side glenoid fossae and altered TMJ discs. Increased stimulation of TMNe by TRH is the postulated mechanism for the observed seauelae.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology