The photoperiod and heat stress effects on histometrical structure of rat prostate gland

BACKGROUND: There is not enough information about theeffects of heat stress and photoperiod on different lobes structure.OBJECTIVES: The present study aims at determining thehistological changes and the rate of changes in each lobes of ratprostate, affected by photoperiod changes and heat stress.METHODS:To this end, 15 adult male wistar rats were divided tothree groups: 1. the control group in which the rats were kept in12L: 12D and 25°C temperature condition, 2. the heat stressgroup in which the rats were kept in 12L: 12D and 42+1 °Ctemperature condition for 4 to 5 hours per day, and 3. thephotoperiod group in which the rats were kept in 16L: 8D and25°C temperature condition. After 30 days, samples were takenfrom different lobes and sections with 5 to 6? thickness weremade and stained by H&E and PAS. RESULTS: The microscopicresults showed that histomorphometrical structure andhistochemical reactions of the different lobs of normal prostateof the rats are different. The proportion of parenchyma to stromadecreased by heat stress; however, it increased by photoperiod.The maximum changes were seen in ventral lobe. The epithelialthickness, lumen diameter, and number of secretory units alsoincreased by photoperiod (16L:8D), but it decreased by heatstress. The number of secretory cells were increased by heatstress because the cell size decreased; however, they decreasedby long photoperiod regime. The number of folded secretoryunits increased by photoperiod, while heat stress has an adverseeffect (p<0.001). The serum testosterone increased by longphotoperiod and decreased by heat stress (p<0.01).CONCLUSIONS: This study shows that long photoperiod hasimportant effects on increasing the rat prostate parenchyma andits activity.

کلیدواژه ها:

heat stress ، histometrical ، photoperiod ، rat prostate