Veterinary Physiology-III

MELANOCYTE STIMULATING HORMONE (MSH) AND beta - LIPOTROPIN (LPH)

• Colour change in response to change in illumination and temperature observed in reptiles, amphibians and fishes is caused by the dispersion or concentration of melanin pigments in melanophores which changes the skin colour
• The skin colour change is under the control of MSH or intermedin of pars intermedia of the anterior pituitary.
• In warm- blooded animals, melanophores are not present but melanin pigments are synthesized by melanocytes and MSH accelerates melanin synthesis and darkening of skin.
• MSH and ACTH have overlapping activities.
• α and β - MSH are cleaved from ACTH and β -lipotropic hormone (LPH) respectively.
• The β -LPH may be a prohormone for the endogenous opiates.
• β -LPH may also have a role in stress.