Summary
The objective of the present study was to investigate the regulation of a key component
of testicular androgen biosynthesis, i. e. the cytochrome P450XVII of the steroid-17α-monooxygenase/C
17,20-lyase, after surgical induction of bilateral cryptorchidism in vivo. Seven days
after induction of cryptorchidism, P450XVII concentrations are diminished (as compared
to sham-operated controls) by 64% in isolated purified Leydig cells but only by 44%
in the total Leydig cell compartment of the testis, since the Leydig cell yield from
cryptorchid testes is by 53% higher than that from control testes. Using microsomal
suspensions prepared from testicular homogenates, P450XVII content per testis equivalent
is found to be decreased by 36% seven days after induction of cryptorchidism, whereas
the P450XVII concentration per gram testis is not changed due to testicular involution.
Fourteen days after induction of cryptorchidism, the induction of the Leydig cell
system appears to superimpose on the downregulation of P450XVII. The study demonstrates
both a strong sensitivity of P450XVII to short-term elevation of testicular temperature
and a differentiation between effects of cryptorchidism on total testicular content
and specific cellular and subcellular concentration of this steroidogenic protein.
Key words
Cryptorchidism - Cytochrome P450 - Leydig Cells - Steroidogenesis - Temperature Effects
- Testis
