RESUMEN

The objective of this study focused on the comparative morphological and histochemical analysis of the duodenum of fetuses, juveniles and adult coypu (Myocastor coypus bonariensis), the major socioeconomic wildlife resource of Argentina. Histological and histochemical procedures for in situ characterization of glycoconjugates (GCs) were used. This study evidenced that fetal mucins differ histochemically in many respects from their adult counterparts. Only in fetuses from 90 days-post coitus (dpc) glycogen-rich sites were observed throughout the duodenal epithelium. The goblet cells appeared from 105 dpc and their secretory content varied considerably after birth. Duodenal glands presented scanty neutral and sulphated GCs in the 30-day juveniles; in adults the proportion of these GCs increased, and carboxylated and sialylated GCs were also observed. The results obtained in this work may be used in future studies to evaluate the effects of diet and intestinal pathologies in the glycosylation pattern of GCs. Also, knowledge of the normal glycoprofile of the duodenum of M. coypus bonariensis during its ontogenetic development may constitute a basis for the study of this organ in other Hystricognathi rodents.

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RESUMEN

Se efectuaron los análisis anatómico e histoarquitectónico del oviducto del coipo (Myocastor coypus) en la madurez sexual. Se trabajó con 34 oviductos que fueron segmentados en infundíbulo, ampolla, unión ámpulo-ístmica, istmo cefálico, medio y caudal y procesados con técnicas histológicas de rutina. Los oviductos se observaron como órganos tubulares y tortuosos, con amplia superficie infundibular, marcada flexura en la unión con los cuernos uterinos y el desarrollo de un colículo en la unión útero-tubárica. La mucosa presentó plegamientos que disminuyeron en número, grado de ramificación y altura desde la ampolla hasta los comienzos de la unión útero-tubárica. El epitelio de revestimiento estuvo compuesto por células ciliadas y células secretoras. En el infundíbulo y el istmo fue cilíndrico simple, en tanto que en la ampolla fue seudoestratificado cilíndrico. En las regiones caudales del istmo se observaron criptas revestidas por un epitelio cilíndrico de aspecto secretor. La lámina propia fue de tejido conectivo laxo y muy vascularizado. La túnica muscular incrementó su grosor y complejidad desde el infundíbulo a la unión útero-tubárica.

Anatomical and histoachitectonic analyses of coypu (Myocastor coypus) oviduct were performed at sexual maturity. Thirty-four oviducts were segmented into: infundibulum, ampulla, cephalic istmus, middle and caudal. Routine histological techniques were used. Oviducts were observed as tubular and tortuous organs with a wide infundibular surface, a pronounce flexure at junction of the uterine horns and with a colliculus at the utero-tubaric junction. The oviductal wall was composed of the mucosal, muscular and serosal tunics. The mucosal tunic showed foldings that diminished in number, ramification and height from the ampulla to the beginning of the utero-tubaric junction. The lining epithelium was composed of ciliated cells as well as secretory cells. In the infundibulum and isthmus, it was simple and cylindrical, while in the ampoule it was cylindrical pseudo-stratified. In the caudal regions of the isthmus, crypts covered by a cylindrical epithelium with secretroy aspect were observed. The lamina propria was composed of highly vascularized lax connective tissue. The muscular tunic increased its thickness and complexity from the infundibulum to the utero-tubaric junction.

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