<prompt> According to myogenic hypothesis of renal autoregulation, the afferent aerioles contract due to -NO releaseNoradrenaline releaseOpening of Ca2channelsAdenosine release  <response>: According to the myogenic mechanism of autoregulation, the rise in aerial pressure stretches the afferent aeriole. Stretch of vascular smooth muscle causes opening of membrane Ca2 channels. This increases intracellular Ca2, leading to contraction of the smooth muscle. NO and adenosine:are involved in the TG feedback. They are released by macula densa in response to changes in NaCl in tubular fluids. Norepinephrine:acting a1 receptors located mainly in the afferent aeriole, cause vasoconstriction. Dehydration and strong emotional stimuli fear, pain activates sympathetic nerves and reduce RBF and GFR. Prostaglandins PGs: produced locally within the kidneys during pathophysiologic conditions increase RBF without changing the GFR. 