Structure of the adenohypophysis in parturient female and neonate harp seals,Pagophilus groenlandicus

Summary The pars distalis of parturient harp seals (Pagophilus groenlandicus) is divisible into three distinct zones based on the major cellular components of the different regions. A clear zonation is lacking in neonate seals, the medial basophilic wedge and the anterior gonadotrophic were small and difficult to identify. Five cell types were identified based on cytological characteristics: somatotrophs, mammotrophs, thyrotrophs, gonadotrophs and stellate cells; corticotrophs could not be identified, with any certainty, in any of the preparations, nor could the gonadotrophs be classified into LH, FSH, and ICSH cells.The pars intermedia enlarged during the early post-partum period and was large in the parturient females.Abbreviations Used LH luteinizing hormone - FSH follicle stimulating hormone - ICSH interstitial cell stimulating hormone - PAS periodic acid-Schiff We wish to thank Mrs. Lucy Lin for her technical assistance. The work was supported by grants-inaid of research to J.F.L. and K.R. from the National Research Council of Canada and a grant from the Donner Canadian Foundation to K.R.