Identification of stage-specific changes in protein secretion by isolated seminiferous tubules from rats following exposure to short-term local testicular heating.
The objective of this study was to identify the early (after 4 and 24 h) effects of short-term local testicular heating (43 degrees C for 30 min) on the secretion of proteins by seminiferous tubules isolated from adult rats at stages II-V, VI-VIII or IX-XII of the spermatogenic cycle, and cultured in vitro for 24 h with [35S]methionine. Incorporation of [35S]methionine into secreted and intracellular proteins was assessed and the pattern of protein secretion was evaluated using two-dimensional SDS-PAGE. Seminiferous tubules isolated from control rats exhibited the characteristic, androgen-dependent increase in protein secretion at stages VI-VIII. At 4 h after exposure to local testicular heating, seminiferous tubules at these stages showed a significant increase (P < 0.001) in the overall incorporation of [35S]methionine into secreted proteins, whereas seminiferous tubules at stages II-V and IX-XII showed no significant change. In marked contrast, seminiferous tubules isolated from rats 24 h after local testicular heating showed a significant decrease in the incorporation of [35S]methionine into secreted proteins at stages VI-VIII (P < 0.001) and to a lesser extent at IX-XII (P < 0.05), whereas seminiferous tubules at stages II-V showed no change in incorporation. Prior treatment to maintain normal intratesticular concentrations of testosterone in heat-exposed rats failed to prevent these changes. Similar results were obtained when incorporation of [35S]methionine into intracellular proteins was evaluated 4 and 24 h after exposure to local testicular heating.(ABSTRACT TRUNCATED AT 250 WORDS)
McLaren
T T
TT
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, UK.
Foster
P M
PM
Sharpe
R M
RM
D000818:Animals; D046508:Culture Techniques; D015180:Electrophoresis, Gel, Two-Dimensional; D006358:Hot Temperature / Q000009:adverse effects*; D008297:Male; D008715:Methionine / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012671:Seminiferous Tubules / Q000166:cytology / Q000378:metabolism*; D013091:Spermatogenesis / Q000502:physiology; D013997:Time Factors
D011506:Proteins; D008715:Methionine