Hypophysis cerebri is considered the master endocrine gland as it plays a directly critical roles in influencing and controlling the vitality of other endocrine organs via several hormones secretion.
The present study was performed to clarify the localization of Wulzen's cone within sheep hypophysis and cytodifferentiation of the glandular cells filling cone parenchyma with special emphasis on the cone correlations with adjacent pars distalis, pars intermedia and pars nervosa.
Pituitaries were collected and processed histologically then subjected to different combinations of special stains; Br-AB- OFG., PFA-AB-PAS-OG., PAS-Orange G., Orange G- Acid Fuchsin- Light Green, Bielschowsky technique, Masson's trichrome and Gomori's reticulin.
A sagittal section through pituitaries revealed a well-developed cone of glandular cells protruded from the pars intermedia like a tongue plate towards the hypophyseal cleft in the neighborhood of the pars distalis and behind to the pars nervosa. Resembling the pars distalis, various glandular cells were distinguished in the cone; chromophobes and chromophils of acidophils and basophils. The cone is mainly formed from acidophils intermingled with the chromophobes. Meanwhile, basophils were mainly localized at the most anterior and posterior part of the cone. In front of the cone, pars distalis were localized resembling a wing- shaped and filled with several categorized glandular cells; chromophobes and chromophils. Upper to the cone, pars intermedia were localized and composed mainly with weakly basophilic cuboidal or polygonal cells that arranged in parallel cords or in follicles. Behind to the cone, pars nervosa was localized as a ventral out pouching of the brain floor like a water- drop. Unlike the cone, it was devoid from any glandular secretory cells or nerve cells but consisted mainly of unmyelinated nerve fibers, herring bodies and pituicytes.
Wulzen's cone is present and well-developed in sheep adenohypophysis. Various glandular cells were distinguished filling the cone, chromophobes and chromophils of acidophils and basophils that were typically similar to the glandular cells of pars distalis but with different distributions.
Key words: Cephalic cone, Wulzen cone, Pars distalis, Pars intermedia, Pars nervosa.