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Effects of short-day photoperiods on the ventral and dorsal prostates of the syrian hamster
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D3 EFFECT OF LIGAT WAVELBNGTA ON THE SEASONAL COLLAPSE OF TAE MALE SYRIAN G_ Brainard*, G. Alexander, and R. BAMSTER REPRODUCTIVE SYSTEM. Neurology, TJU, Philadelphia, Pa. 191O~US~ Schwartzman , Dept. The hamster pineal gland and reproductive axis are differentially responsive to different wavelengths of visible light (Brainard et al., Sot. The purpose of this study was to determine Neuroscience Abs. 96.5, 1983). the effectiveness of one hour pulses of different wavelengths of light in blocking the short photoperiod-induced collapse of the hamster reproductive (LD Groups of 10 hamsters each ware 2xposed to short photoperiods system. lo:141 of bright white light at 400 "W/cm , interrupted during the dark periods by a one hour pulse of either near-ultraviolet, blue, green, yellow Additional groups of hamsters were exposed to either a long or red light. photoperiod (LD 14:lO) or a short photoperiod uninterrupted by light. Restricted wavelength sources had half-peak bandwidths of 330-371 nm (near-ultraviolet), 435-500 nm (blue), 515-550 nm (green), 558-636 nm The lights used to intqrrupt the dark periods (yellow), 635-770 nm (red). were adjusted to produce an irradiance of 0.2 "W/cm . After 12 weeks, Blood samples paired testes, accessory sex organs and spleens were weighed. Animals exposed and pituitary glands were collected for radioimmunoassay. to the long photoperiod or the short photoperiod interrupted by a pulse of near-ultraviolet, blue or green light had testicular and accessory sex organs weights which were typical of reproductively competent hamsters. Animals exposed to the uninterrupted short photoperiod or the short photoperiod interrupted by red or yellow light pulses, had significantly These data confirm that the depressed testicular weights (P
D4 EFFECTS OF SHORT-DAY PHOTOPERIODS ON THE VENTRAL AND DORSAL PROSTATES OF THE SYRIAN HAMSTER. G.R. Buzzell*, J.G. Toma, M.G. O'Brien, J. Haskins, Department of Anatomy,mversity of Alberta, Edmonton, Alberta T6G 2H7, Canada. In Syrian hamsters, short-day photoperiods, acting via the pineal, have relatively little effect on the weights of the ventral prostate (VP) but induce regression of the dorsal prostate (DP). We studied these contrasting effects by lightmicroscopic stereology, comparing animals kept in short-day photoperiods with long-day controls. In the VP, animals kept in short days show significant increases in the volume fraction and mean thickness of the lamina propria and a small but significant decrease in the mean acinar radius. In the DP, animals kept in short days show a decrease in the volume fraction and an increase in the length fraction of secretory acini. Within the acinus, there is an increase in the volume fractions of lamina propria and muscular stroma and an increase in the surface to volume ratio of the secretory epithelia. There is a significant decrease in the mean acinar radius, an increase in the mean thickness of the epithelium, and decreases in the mean thicknesses of lamina propria and stroma. Thus, different lobes of the prostate are affected in different ways by pineal antigonadotrophic influences. Supported by the Alberta Cancer Board.
D3 EFFECT OF LIGAT WAVELBNGTA ON THE SEASONAL COLLAPSE OF TAE MALE SYRIAN G_ Brainard*, G. Alexander, and R. BAMSTER REPRODUCTIVE SYSTEM. Neurology, TJU, Philadelphia, Pa. 191O~US~ Schwartzman , Dept. The hamster pineal gland and reproductive axis are differentially responsive to different wavelengths of visible light (Brainard et al., Sot. The purpose of this study was to determine Neuroscience Abs. 96.5, 1983). the effectiveness of one hour pulses of different wavelengths of light in blocking the short photoperiod-induced collapse of the hamster reproductive (LD Groups of 10 hamsters each ware 2xposed to short photoperiods system. lo:141 of bright white light at 400 "W/cm , interrupted during the dark periods by a one hour pulse of either near-ultraviolet, blue, green, yellow Additional groups of hamsters were exposed to either a long or red light. photoperiod (LD 14:lO) or a short photoperiod uninterrupted by light. Restricted wavelength sources had half-peak bandwidths of 330-371 nm (near-ultraviolet), 435-500 nm (blue), 515-550 nm (green), 558-636 nm The lights used to intqrrupt the dark periods (yellow), 635-770 nm (red). were adjusted to produce an irradiance of 0.2 "W/cm . After 12 weeks, Blood samples paired testes, accessory sex organs and spleens were weighed. Animals exposed and pituitary glands were collected for radioimmunoassay. to the long photoperiod or the short photoperiod interrupted by a pulse of near-ultraviolet, blue or green light had testicular and accessory sex organs weights which were typical of reproductively competent hamsters. Animals exposed to the uninterrupted short photoperiod or the short photoperiod interrupted by red or yellow light pulses, had significantly These data confirm that the depressed testicular weights (P
D4 EFFECTS OF SHORT-DAY PHOTOPERIODS ON THE VENTRAL AND DORSAL PROSTATES OF THE SYRIAN HAMSTER. G.R. Buzzell*, J.G. Toma, M.G. O'Brien, J. Haskins, Department of Anatomy,mversity of Alberta, Edmonton, Alberta T6G 2H7, Canada. In Syrian hamsters, short-day photoperiods, acting via the pineal, have relatively little effect on the weights of the ventral prostate (VP) but induce regression of the dorsal prostate (DP). We studied these contrasting effects by lightmicroscopic stereology, comparing animals kept in short-day photoperiods with long-day controls. In the VP, animals kept in short days show significant increases in the volume fraction and mean thickness of the lamina propria and a small but significant decrease in the mean acinar radius. In the DP, animals kept in short days show a decrease in the volume fraction and an increase in the length fraction of secretory acini. Within the acinus, there is an increase in the volume fractions of lamina propria and muscular stroma and an increase in the surface to volume ratio of the secretory epithelia. There is a significant decrease in the mean acinar radius, an increase in the mean thickness of the epithelium, and decreases in the mean thicknesses of lamina propria and stroma. Thus, different lobes of the prostate are affected in different ways by pineal antigonadotrophic influences. Supported by the Alberta Cancer Board.