ITT-5 Mechanisms of Spermatogenesis in Man

This is a nine-month research study examining the effects on androgen treatment on sperm
production in healthy men. There are three phase to the study, a 2-month screening phase,
4-month treatment and 3-month follow-up. In this study, the investigators aim to define a
quantitative relationship between intra-testicular testosterone (IT-T) and spermatogenesis in
man. Hormone levels will be measured in a small amount of testicular fluid at the beginning
and end of treatment and sperm concentration will be measured.

Inclusion Criteria:

- Males age 18-55

- In general good health based on normal screening evaluation

- Normal serum testosterone, lutenizing hormone (LH) and follicle stimulating hormone
(FSH)

- Prostate Specific Antigen (PSA) < 3.0

- Agrees not to donate blood or participate in another research study during the study

- Informed consent

- Must be willing to use a reliable form of contraception during the study

Exclusion Criteria:

- Participation in a long-term male contraceptive study within the past three months

- History of testosterone or anabolic steroid abuse in the past

- History of or current skin disorder that will interfere with testosterone gel

- Poor general health or significantly abnormal screening blood results

- History of or current testicular or prostate disease

- History of a bleeding disorder or need for anticoagulation

- History of untreated sleep apnea and/or major psychiatric problems

- BMI > 32

- History of or current liver disease

- Chronic pain syndrome

- Current use of terfenidine, astemizole, cisapride, budesonide, felodipine,
fluticasone, lovastatin, midazolam, sildenafil, or vardenafil

- Use of glucocorticoids or underlying adrenal insufficiency

- Active drug or alcohol abuse within the past year