Hormones – An Introduction

FSH – A peptide hormone

Method of Action – Steroid Hormones

Steroids transport via carrier proteins – why?

Movement through plasma membrane into cytoplasm of target

Interaction with specific receptors Binding to response elements in

target genes Influence on transcription

AF1 DNA binding/Dimerisation Ligand Binding

Steroid receptor structure

Transact DBD NL Transact

DNA Sequence – Differs, depending on receptor complexeg., GGTCAnnnTGACCC for estrogen receptor bound to ligand

Method of Action – Peptide Hormones

Interact with ligand bound receptor on plasma membrane – why?

Consequence of interaction with receptor is signal transduction – eg., activation of GTP, influence on adenylate cyclase/cAMP/protein kinase

Gene activation indirect, but signal amplification can be more rapid

G-Protein Coupled Receptor Function

Richardson, 2001

Hypothalamic-Pituitary Axis: An Historical Perspective

                                                          

                           

Michelangelo’s “Creation of Adam”

Outline of Brain

FUNCTIONAL ANATOMY OF THE HYPOTHALAMUS AND PITUITARYChapter 3b - Ronald M. Lechan, M.D., Ph.D., and Roberto Toni, M.D.

Neurohypophysis= Posterior Pituitary (neurons that extend here have cell bodies in hypothalamus

Adenohypophysis = Anterior Pituitary “Glandular”

Hypothalamic/Pituitary Axis – Vasculature and Gross Morphology

Adapted from http://www.uwyo.edu/wjm/Repro

Pituitary Histology

Note the differences in morphology and staining patterns (acidophilic vs basophilic) reflecting differences in secretions

b/w cell types. Tissue is also highly vascularized

GH, PRL secreting

FSH, LH etc