Testes samples of 52 brown hares (Lepus europaeus L.), sacrificed between July and January, were subjected to immuno histochemical analysis. The terminal deoxynucleotidyl transferase-mediated d'UTP nick end labelling (TUNEL) method was applied to detect apoptosis; and antibodies to proliferating cell nuclear antigen (PCNA) were used to evaluate cell proliferation in the testes. In the seminiferous epithelium, the apoptotic processes were evident from August to early November with maximal values in September. Cell death in germ cells occurs predominantly during the prophase of the first meiotic division. In July, and from mid-November onwards, only the occasional TUNEL-positive cells can be seen. The proliferation of germ cells continues during the testis regression phase. The average number of PCNA-positive cells decreases slightly from September onwards and rises again in mid-November.

Important functions of the oviduct during reproduction include the provision of an optimal environment for gametes and zygotes and nutrition of the early embryo. These functions are ensured by the secretion of an oviductal fluid which is known to contain organ-specific glycoproteins. Glycoconjugates of the apical glycocalyx are considered to play a major role in cell recognition and interaction processes. In the present investigation, binding patterns of Con A, HPA, LTA, RCA I, UEA I, and WGA were studied in defined segments of the oviduct (infundibulum, ampulla, isthmus) and in the uterus during the oestrous cycle. The carbohydrate distribution showed regional as well as time dependent differences. LTA, HPA and WGA reacted strongly with Golgi regions and secretory granules in the oviduct epithelium during the follicular phase, indicating high secretory activity. LTA, HPA, and UEA I also revealed a varying carbohydrate composition of the glycocalyx during the oestrous cycle. Prominent regional differences in glycoconjugate expression were shown in oviductal segments by LTA and HPA binding : during the follicular phase, LTA binding sites were only present on epithelial cells of the isthmic segment, the ampulla and infundibulum being unreactive. D-N-acetyl-galactosamine residues were demonstrated on ciliated epithelial cells of the ampulla and infundibulum exclusively during oestrus. The glycocalyx of uterine epithelial cells was clearly defined by HPA, WGA, LTA, RCA I and UEA I ; LTA binding was restricted to the secretory phase. The observation of regional and time dependent variability in glycoconjugate distribution strongly indicates their specific physiological functions in reproductive processes.Key words : Pig ; uterus ; oviduct ; glycoconjugates ; lectins. The female reproductive tract is the site of complex processes, such as oocyte maturation, capacitation of spermatozoa, fertilisation, and embryonic development. It has been considered that the oviduct and uterus-in addition to hormonal control-are influenced by oocyte or embryonic signals (Hunter, 1988). However, more detailed information on interactions between oviduct\uterine mucosa and the ovum or the early embryo is still lacking. Physiological significance was suggested for the luminal glycoconjugate-surface coat (glycocalyx) of the epithelial layer in the oviduct and uterus, and for the oviduct fluid. The apical glycocalyx acts as a mediator

Brown hare is a seasonal breeding mammal and under the influence of photoperiod the spermatogenesis ceases during autumn months - most markedly in September and October. Testis samples from 34 animals, sacrificed between July and December were fixed in Bouin solution, embedded in paraffin, subjected to immunohistochemistry and analysed by light microscopy. TUNEL (terminal deoxynucleotidyl transferase-mediated d'UTP nick end labeling) method was applied to detect apoptosis, anti PCNA (proliferating cell nucleolar antigen) antibodies were used to evaluate cell proliferation and antibodies against apolipoprotein D and 3beta-HSD (3beta-hidroxysteroid dehydrogenase) to evaluate the activity of the Leydig cells. Our results show that the apoptotic processes in seminiferous epithelium are obvious in August and reach peak in September, with cell death occurring during prophase of I meiotic division. In July, and from early November onwards only occasional TUNEL positive cells can be seen. The proliferation of the germ cells continues also during phase of regression (September, October and early November). Active testosterone producing Leydig cells appear to be absent in September, whereas their activity becomes obvious in the middle of November.

The position and histological structure of the testes of 33 brown hares (Lepus europaeus) were studied from July to December. From July to September, the testes were located in the scrotum; in October and November, in some animals, the testes were positioned more or less in the inguinal canal towards the abdominal cavity, and in December none of the investigated animals had testes located in the scrotum. Testes were weighed and a quantitative analysis of tissue components was performed: the diameter of the seminiferous tubules, the depth of the seminiferous epithelium, the thickness of the tunica albuginea, the thickness of the peritubular tissue and the relative proportion of seminiferous tubules were determined. The tunica albuginea and peritubular tissue were thickest in September, October and at the beginning of November. In the same months the testis weight was low, and the diameter of the seminiferous tubules, the depth of the seminiferous epithelium and the relative proportion of seminiferous tubules in the testis tissue were significantly lower than in other months. We did not find any correlation between testicular regression or testis weight reduction and the change in the position of the testes. During recrudescence of spermatogenesis in November and December the testes were located in the inguinal canal.

The immunohistochemical study of chamois (Rupicapra rupicapra L.) skin showed that a limited number of available monoclonal and polyclonal antibodies expressed reactivity with skin cell components. These included cytokeratins, vimentin, desmin, neuron-specific enolase and S-100 protein with almost the same distribution pattern as already described in the skin of humans and animals. Antibodies used for labelling skin-associated lymphoid tissues and other cells with the immunologic function in human skin failed to demonstrate these cells in the chamois skin with the exception of LCA and OKT6 antibodies. Epidermal Langerhans cells were reliably demonstrated only by the enzyme histochemical method for adenosine triphosphatase, while the majority of mononuclear cells in dermal infiltrates showed a strong immunoreaction with OKT6 antibody. The histologic and histochemical analysis showed that the dermal infiltrations in infested skin consisted of macrophages, lymphocytes, granulocytes, mastocytes and fibroblasts. The chamois skin affected with sarcoptes mange showed a significant loss of cytokeratins in the epidermis and its derivatives. Particular keratinocytes showing nonspecific staining with several antibodies were also described and discussed in this paper.