There is considerable evidence supporting the role of gonadotrophins and
progesterone on follicular growth and maturation and functional maintenance
of the ovary in the hen. Recently, however, there are ever-expanding list of
factors may be involv
ed in establishing follicular growth and ovulation
currently including germinal disc region, growth factors, macrophages,
plasminogen activator, ornithine decarboxylase, inhibin, activin, follistatin,
relaxine, arginin vasotosin, oxytocin, prostaglandines, vasoactive intestinal
peptide, and their interactions.
The ovary of a laying hen contains follicles in the rapid growth phase
which have advanced from a pool of follicles in the resting stage of about
٦-٨ mm in diameter. Little is known about mechanisms regulating follicular
transformation from the re
sting stage to the rapid growth phase. One potential
regulator of this transformation may be Follicle Stimulating Hormone
(FSH). In addition, there are accumulating results indicating that a negative
relationship between inhibin and FSH may be existed.