C. Tumor cells secrete hormone-like
peptides(ectopic secretion ) as ectopic ACTH secrecting syndrome
HORMONE (NEW CONCEPT)
A chemical mediators secreted by a highly differentiated endocrine cell, which reaches via circulation or by direct dissemination to its target cells,and binds to its specific receptors and thereby initiates physiologic effects .
Omentin (2003)
PPARs
Vitronectin Adiponectin
Resistin
B. Local action (paracrine )
spermatogenesis enhanced by local testosterone AT2 promote proadipocyte differentiation
AN INTRODUCTION TO CLINICAL
ENDOCRINOLOGY
( Essential for Medical Students )
SCOPE OF ENDOCRINOLOGY
Endocrinology deals with the function of the endocrine organs , tissues , or cells ,and their secretory products ,i .e./hormones ,the mechanism of hormone action ,Dx and Rx of hormone dysfunction.
PHYSIOLOGICAL EFFECTS OF H
A . Regulate the entire processes of reproduction (gametogenesis ,sexual behavior and intercourse , fertilization , nourishment of fetus and newborn )
D . Energy Production , Utilization , and Storage Glycogen and fat breakdown by E and glucagon , gluconeogenesis and ketogenesis from FFA and A.A., and the oxidation of fuel by cortisol , glucagon and thyroid hormone Anabolic metabolism ,on the otherhand , is dependent on insulin , leptin and NPY etc
B . Promote the growth and development
C . Maintain the internal environment and hence facilitate the metabolic activitves of the cells by regulating the conc.of electrolytes ,pH↑, volume, BP,HR and enzymatic activities . Respond to the emergent challenge imposed by the environment (starvation, infection , trauma , psychogenic stress)
Characteristics of hormonal action :
A . Molecular Specificity
Small changes in mol structure cause drastic alterations in activity .
B . Tissue Specificity C . Amplification of H effect a small number
IL-6，（MP，LC，AC）
The mosalking
hepotic
TNF-α
↑ TG
↑lipolysis
O P
（—）
AC
IL-6↑
E2
HPA AXIS↑
（一）F （—）
↑CRP OB-low grade inflammatory state→As
Challenges to the classical concept:
A . Non-endocrine organs secrete H.
◇ Neuron(neurotransmitter) ◇ GI tract (GIH) ◇ Atrial muscle (atriopeptin) ◇ kidney (Renin,PG ,VitD, EP) ◇ Endothelial(Endothelin ,NO) ◇ neuro-endo-immune net works
HORMONE (TRADINAL CONCEPT)
A chemical substance secreted by an endocrine gland and transported via blood stream and effected to its target tissues. (traditional endocrinology deals with the glands.) H was firstly termed by Starling in 1905(Croonian Lect to Royal College“The Chemical Correlation of the Functions of the Body”)