Male erectile dysfunction by Peter Stacey
The chances are that you’ll have heard something about sildenafil —
marketed under the trade name Viagra™ (Figure 1). Launched in 1998
Natalie Mount
as a tablet for treating male erectile dysfunction (MED), it’s now been
used by over 15 million men and has attracted plenty of publicity.
As a biochemist however, you’ll probably want to go one step further.
This review will take a closer look at the interesting biochemical details
Impotence
to impaired blood flow in the penis.
significant strain on their relationships.
oral medicine like sildenafil3, it’s not
Physiology of erection NO and cGMP
The Biochemist — April 2002. 2002 The Biochemical Society
direct effects in these cells (Figure 3).
inhibitor is measured in vitro in a high
equal to the inhibition constant Ki
sildenafil’s potency in vivo. Other
Phosphodiesterase
experiments in vitro, using strips of
electrical nerve stimulation8 (Figure 5). Side effects stimulation
experienced by some sildenafil users.
The Biochemist — April 2002. 2002 The Biochemical Society
% activity sildenafil conc. (nM) PDE family
variety of tissues, it is likely they will
References
1. Levine, L.A. (2000) Prim. Care Update Ob. Gyns. 7, The future
2. McKinlay, J.B. (2000) Int. J. Impot. Res. 12 (Suppl.
selectivity is approximately 10-fold8.
3. Boolell, M., Allen, M.J., Ballard, S.A., Gepi-Attee, S.,
Muirhead, G.J., Naylor, A.M., Osterloh, I.H. and
Gingell, C. (1996) Int. J. Impot. Res. 8, 47–52
awareness of male erectile dysfunction.
4. Andersson, K.E. (2001) Pharmacol. Rev. 53, 417–450. 5. Lincoln, T.M., Dey, N. and Sellak, H. (2001) J. Appl.
Physiol. 91, 1421–1430
6. Corbin, J.D. and Francis, S.H. (1999) J. Biol. Chem. 274, 13729–13732
7. Stacey, P., Rulten, S., Dapling, A. and Phillips, S.C.
(1998) Biochem. Biophys. Res. Commun. 247, 249–254
8. Ballard, S.A., Gingell, C.J., Tang, K., Turner, L.A.,
Price, M.E. and Naylor, A.M. (1998) J. Urol. 159,
9. Torphy, T.J., Barnette, M.S., Underwood, D.C.,
Griswold, D.E., Christensen, S.B., Murdoch, R.D.,
Nieman, R.B. and Compton, C.H. (1999) Pulm.
Pharmacol. Ther. 12, 131–135
Peter Stacey and Natalie Mount are drug discovery
biology team leaders, working in the sexual health therapeutic area, at Pfizer Global Research and
Development, Sandwich, Kent, UK. Peter joined Pfizer in
1997 after obtaining a Biochemistry degree at Oxford
University, and a PhD at the Imperial Cancer Research
Fund in London. Natalie joined Pfizer in 1996 after a
Natural Sciences degree at the University of Cambridge
and PhD from University College, London. 159, 2164–2171.
The Biochemist — April 2002. 2002 The Biochemical Society
Name: Period: Date: Birth Control Pill Article When Enovid -- the first birth control pill -- was introduced in 1960, it was a revolution in contraception. For the first time, women could take control of their own reproductive cycles. According to Eve Espey, MD, Enovid ushered in "a whole new world for birth control." Espey is associate professor in the depar
HIGH STRENGTH FINE GRAINED STRUCTURAL STEEL DILLIMAX 890 is a high strength quenched and tempered, fine grained structural steel with a minimum yield strength of 890 N/mm² in its delivered condition (referring to the lowest thickness range), whose mechanical properties are achieved by water quenching followed by tempering. DILLIMAX 890 fulfils the requirements of EN 10 137. It is preferentia
Male erectile dysfunction
direct effects in these cells (Figure 3).
% activity