title: Effects of different light wavelengths at equal irradiance on testis weight, protein content, and K-paranitrophenylphosphatase activity in the Syrian hamster.
abstract: The effects of different light wavelengths at equal irradiance on testis weight, testis protein content, and testis K-paranitrophenylphosphatase (K-pNPPase) activity were studied in the Syrian hamster. One group (long photoperiod) was maintained on a light:dark cycle of 14:10, and another group (short photoperiod) on a cycle of 10:14. Five other groups were maintained on a cycle of 10:14 but with a one hour pulse of equally intense illumination in the middle of the dark period with UV, blue, green, yellow or red light. Animals exposed to a long photoperiod or UV, blue or green light pulses had significantly greater testis weights--up to eightfold greater than those in the yellow or red or short photoperiod groups. Organ protein content closely paralleled organ weight, but the protein/wet weight ratio was consistently higher in the large organ groups. K-pNPPase and Mg-pNPPase activities were significantly higher in the large organ groups, even when expressed per mg protein. Therefore, at a balanced irradiance of 0.2uW/cm2, light wavelength exerts a profound effect on testicular weight, protein content, and K-pNPPase and Mg-pNPPase activities. Testicular involution is a process that is selective with regard to protein biosynthesis.
mesh_terms: D009597:4-Nitrophenylphosphatase / Q000378:metabolism*; D000818:Animals; D006224:Cricetinae; D008297:Male; D008647:Mesocricetus; D009929:Organ Size / Q000528:radiation effects; D010507:Periodicity; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D013737:Testis / Q000033:anatomy & histology / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D011506:Proteins; D010744:Phosphoric Monoester Hydrolases; D009597:4-Nitrophenylphosphatase