Testosterone and hydrocortisone-stimulated responses of reduced pyridine nucleotide fluorescence in prostates cultured from castrate rats

1. Addition of testosterone to prostate organ cultures containing 0.1% glucose is followed after 40 to 60 min by a gradual increase in reduced pyridine nucleotide fluorescence. In several experiments oscillations were superimposed upon the increasing steady-state fluorescence level. The average increase in fluorescence was 8.5%.

2. When a similar experiment was done in medium containing 0.05% glucose only a 2% increase in fluorescence was seen.

3. A single addition of glucose to the testosterone-pretreated prostate resulted in an increase in reduced pyridine nucleotide fluorescence of 6%. Stepwise additions of both equal and larger amounts of glucose produced similar but smaller change in fluorescence.

4. Hydrocortisone addition to prostates produced a cycle of fluorescence which began within 2 min, attained a maximum within 5–12 min and was complete within 20–30 min. Addition of testosterone after the hydrocortisone response is complete stimulates an immediate increase in fluorescence to a level 10 to 15% higher than that seen before testosterone addition.

5. N₂-air cycles before hydrocortisone and testosterone showed a change in fluorescence of 4%. After hydrocortisone and testosterone the change in fluorescence in response to N₂ was 9%. This indicated that a doubling of the amount of pyridine nucleotide linked to respiration occurred. However, the increase in the steady-state fluorescence was 15%, indicating that there was an equivalent increase in glycolytic pyridine nucleotide.

6. The addition of 17β-estradiol produced an immediate small increase in the fluorescence signal which can be explained by its intrinsic fluorescence.