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Juan P. Advis
Professor
Rutgers University
Dept. Animal Sciences
Bartlett Hall
School of Env & Biol Sciences
New Brunswick. NJ 08903
(732) 932-9240
FAX - 6996
advis@aesop.rutgers.edu |
Hypothalamic regulation of luteinizing
hormone. reproduction physiology
To assess if the hypothalamic
median eminence (ME) is a neuroendocrine control site where final
hypophysiotropic release leading to the preovulatory surge of
Luteinizing Hormone (LH). an obligatory event for reproduction to occur. might be ultimately regulated. We have used two animal models for these
studies: hens. showing daily LH preovulatory surges for 15-25 days and
ewes. showing an LH preovulatory surge at the end of each follicular
phase in a 16-day estrous cycle. In our studies. we have concentrated in
assessing the hypothalamic control of LHRH by three of its ME putative
inputs: ß-endorphin (ßEND). dopamine (DA). and neuropeptide Y (NPY).
Through our immunocytochemical studies we mapped the hypothalamic
distribution of LHRH and these three ME putative inputs. in hens and
ewes. On the other hand. in our release studies. we used in vitro
incubations of ME tissue and push-pull cannula (PPC) sampling of in vivo
neuropeptide release from discrete areas of the ME. In addition to our
release studies. we assessed the possibility that enzymatic degradation
of LHRH in the ME might be a regulated event of some physiological
significance. Furthermore. we recently determined steady-state levels of
mRNA and expression of c-fos antigens. in some of these putative inputs
to ME-LHRH neuronal terminals. In addition. we have developed an
extremely sensitive capillary electrophoresis-based assay. that uses
fluorescence microscopy detection of derivatized samples. for the
determination of multiple neuropeptides in ME-PPC perfusate samples.
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