8. Using Table 1 and Figure 4, specifically compare PDE5 and
PDE6 by tissue localization, structure, nucleotide specificity and
regulation.
Part C: PDEs and drug side effects Phosphodiesterases are a large family of enzymes with differing tissue expression and specificity (Table 1). Table 1. Substrate specificities and distributions of PDE families PDE family Subs Tissue localization cGMP CAMP Brain, heart, kidney, liver, skeletal muscle, vascular and visceral smooth muscle CAMP and Adrenal cortex, brain, corpus cavernosurm, heart, kidney, liver, visceral smooth muscle, skeletal muscle cGMP CAMP and Corpus cavernosum, heart, platelets, vascular and visceral smooth muscles, liver, kidney, adipose tissue cGMP CAMP Kidney, lung, mast cells, brain, heart, skeletal muscle vascular and visceral smooth muscle, thyroid, testis, neural tissue cGMP Corpus cavernosum, platelets, skeletal muscle, vascular, airway and visceral smooth muscle cGMP CAMP Skeletal muscle, heart, lymphocytes, putamen, caudate, nucleus, pancreas CAMP Testes, ovaries, small intestine, colon cGMP Spleen, small intestine, brain 10 CAMP and Stratum, testes, thyroid cGMP 11 CAMP and Corpus cavernosum, pitutary, liver, kidney, prostate, skeletal muscle, thymus, testes cGMP