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 6μ 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