• Neurocrine (neurotransmitters)
• Endocrine (hormones)
• Paracrine (cytokines)
• Autocrine (various)
, Hormones
• Proteins / peptides
– Preprohormone (ER, GA, secretion granules)
• Steroids
– Cholesterol
• Amines
– Tyrosine
, Endocrine regulation
• Negative feedback
• Positive feedback
• Production (endocrine gland)
• Transport (binding proteins in plasma)
• Target tissue (receptors on cells)
, Endocrine glands