Objectives. To investigate the effect of cigarette smoke exposure during intrauterine period on neonatal rat testis. Methods. Twenty-five rats were randomized to be exposed to cigarette smoke with the Walton Smoking Machine or to room air during their pregnancies. The newborn male rats ( ) were grouped as group 1 ( ) which were exposed to cigarette smoke during intrauterine life and group 2 ( ) which were exposed to room air during intrauterine life. The orchiectomy materials were analyzed with TUNEL immunofluorescent staining for detection of DNA damage. To detect apoptosis, immunohistochemical analyses with caspase-3 were performed. Primary outcomes were apoptotic index and immunohistochemical scores (HSCORES); secondary outcomes were Sertoli-cell count and birth-weight of rats. Results. Sertoli cell apoptosis was increased in group 1 (HSCORE ) when compared to group 2 (HSCORE ) ( ). Sertoli cell count was decreased in group 1 ( ). The HSCORE for the germ cells was calculated as in group 1 and in group 2 ( ) referring to an increased germ cell apoptosis in group 1. The apoptotic indexes for group 1 were and for group 2 ( ). The immunofluorescent technique demonstrated increased DNA damage in seminiferous epithelium in group 1. Conclusions. Intrauterine exposure to cigarette smoke adversely affects neonatal testicular structuring and diminishes testicular reserve. 1. Introduction Apoptosis or programmed cell death plays an important role in the homeostasis and normal function of all tissues. It is morphologically characterized by disruption of the cell skeleton, cell shrinkage, membrane blebbing, nuclear condensation, cell disruption into small membrane-enclosed fragments, and phagocytosis by neighbouring cells [1]. DNA fragmentation is a key feature of programmed cell death. DNA cleavage during apoptosis occurs at sites between nucleosomes. It is characterized by the activation of endogenous endonucleases with subsequent cleavage of chromatin DNA into internucleosomal fragments [2]. The induction and execution of apoptosis require the cooperation of a series of molecules. Among them, the caspase-cascade signaling system is vital in the process of apoptosis [3]. Generally, the caspase family proteases can be activated through three pathways, mediated by either mitochondrion/cytochrome-C, cell surface receptors, or endoplasmic reticulum [4–6]. Caspase-3, the major effector caspase, is synthesized as an inactive proenzyme and processed during apoptosis into its active form. In this study, caspase-3 was selected because it represents the point of
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