Immunolocalization of anion exchanger 1 (Band 3) in the renal collecting duct of the common marmoset

The purpose of this study was to determine the expression and distribution of band 3 in the collecting duct and connecting tubules of the kidney of the marmoset monkey (Callithrix jacchus), and to establish whether band 3 is expressed in type A intercalated cells. The intracellular localization of band 3 in the different populations of intercalated cells was determined by double-labeling immunohistochemistry. Immunohistochemical microscopy demonstrated that band 3 is located in the basolateral plasma membranes of all type A intercalated cells in the connecting tubule (CNT), cortical collecting duct (CCD), and outer medullary collecting duct (OMCD) of the marmoset. However, type B intercalated cells and non-A/ non-B intercalated cells did not show band 3 labeling. Electron microscopy of the CNT, CCD and OMCD confirmed the light microscopic observation of the basolateral plasma membrane staining for band 3 in a subpopulation of interacted cells. Basolateral staining was seen on the plasma membrane and small coated vesicles in the perinuclear structure, some of which were located in the Golgi region. In addition, there was no labeling of band 3 in the mitochondria of the CNT, CCD and in OMCD cells. The intensity of the immunostaining of the basolateral membrane was less in the CNT than in the CCD and OMCD. In contrast, band 3 immunoreactivity was greater in the intracellular vesicles of the CNT. From these results, we suggest that the basolateral Cl-/HCO3- exchanger in the monkey kidney is in a more active state in the collecting duct than in the CNT.

Localization of estrogen and progesterone receptors in the endometrium of common marmosets Callithrix jacchus.

In the present study, changes in the immunohistochemical localization of endometrial estrogen receptor (ER) and progesterone receptor (PR) during various stages of the ovarian cyclicity in common marmoset, have been reported. Ovarian cyclicity was monitored by estimating plasma estradiol and progesterone. During the early follicular phase, weak ER immunolocalization was observed in the endometrial stroma. During the late follicular phase under the influence of rising estradiol levels, stromal ER localization was intense. During the luteal phase, ER localization was absent in the stroma indicating that high concentrations of progesterone suppressed ER. PR localization was not observed in the stroma during the early follicular phase, while weak staining was seen in the stroma during the late follicular phase. PR localization was maximum during the mid luteal phase. However in marmoset, endometrial ER and PR localization was restricted only to the stroma. This unique feature may be due to the characteristic reproductive profile of this nonmenstruating species and needs to be studied further. Thus it can be hypothesized that in the marmoset endometrium, steroid hormone mediated effects possibly occur directly in the stroma and are then transmitted to the epithelium by autocrine/paracrine action of growth factors and cytokines.