Effects of different light wavelengths at equal irradiance on testis weight, protein content, and K-paranitrophenylphosphatase activity in the skin hamster

John M. Bertoni, Pamela M. Sprenkle, George C. Brainard

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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.

Original languageEnglish (US)
Pages (from-to)1479-1486
Number of pages8
JournalLife Sciences
Issue number15
Publication statusPublished - Apr 13 1987


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)

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