Intracellular receptors are found in:
C i.e. Coicosteroids Classification of Hormones by Lipid/Water Solubility Group I Hormones Feature Group II Hormones Are lipophilic (i.e. lipid or steroid soluble)Q Solubility Are hydrophilic (i.e. water soluble) Being insoluble in water, they are Transpo (Carrier) protein Carrier protein is not required as they transpoed in blood bound to a plasma protein; their association with carrier protein (commonly globulin) circumvents the problem of solubility themselves are water soluble They are not stored & secreted on demand Synthesis & storage They are synthesized in endoplasmic (except thyroid hormones; thyroxine reticulum (ER), like all proteins and stoed stores can last for several weeks) in granules or vesicles. Prolonged (hours-days) d/t transpo protein Plasma half life (ti/2) Sho (minutes) In target cells, they easily penetrate Site of action & Receptor Being lipid in soluble, they act on plasma lipophilic plasma membrane to act membrane receptorsQ, and do not enter the intracellularly in cytosol or nucleus cell to act. Slower in onset and prolonged in Action Rapid in onset and shoer in duration duration. Their actions are terminated in liver. (bcoz cell entery is not required) Hormone -receptor complex undergoes Mediator or Intra cellular messenger Use intracellular second messengers like activation reaction and moves into the c-AMP, c-GMP, IP3-DAG, calcium ? nucleus to bind with high affinity to a specific DNA sequence k/ a hormone response element (HRE). calmodulin and kinases etc. All steroid hormones & thyroid (T3, T4) Examples - Catecholamines (adrenaline & hormonesQ noradrenaline)
Insulin
Glucagon
Coicosteriods
All