KATP Channel Subunits Are Expressed in the Epididymal Epithelium in Several Mammalian Species1

Apr 25, 2008Biology of reproduction

Energy-sensitive potassium channel parts are present in the sperm-carrying tube lining of various mammals

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Positive immunostaining for Kir6.2 (KCNJ11) and SUR2 (ABCC9) was observed in the epididymis of multiple mammalian species.

K(ATP) channel subunits Kir6.2 (KCNJ11) and SUR2 (ABCC9) are present in the principal epithelial cells of the epididymis in rats and mice.
Immunostaining confirmed the colocalization of Kir6.2 (KCNJ11) with aquaporin 9 (AQP9) in principal cells.
Spermatozoa in the epididymal tubules of rodents also exhibited positive staining for Kir6.2 (KCNJ11) and SUR2 (ABCC9).
Western blot analysis detected Kir6.2 (KCNJ11) and SUR2 (ABCC9) protein expression in epididymal extracts from adult rats.
RT-PCR confirmed the presence of Kir6.2 (KCNJ11) and SUR2 (ABCC9) mRNA in both prepubertal and adult mouse epididymis.
Similar immunofluorescence results were observed in the epididymal epithelium and spermatozoa of canine, feline, bovine, and human origin.

AI simplified

Adenosine triphosphate-sensitive K(++) (K(ATP)) channels are poorly characterized in the reproductive tract. The present study was designed to evaluate the putative expression of K(ATP) channel subunits (Kir6.x and SURx) in the epididymis from different mammalian species. Immunohistochemical, Western blot, and RT-PCR techniques were used. A positive immunostaining for Kir6.2 (KCNJ11) and SUR2 (ABCC9) was observed by immunoenzymatic and immunofluorescent approaches in the principal epithelial cells throughout all regions of the rat and mouse epididymis. Double labeling with anti-aquaporin 9 (AQP9) and anti-Kir6.2 (KCNJ11) confirmed their colocalization in the principal cells. No immunostaining could be demonstrated for Kir6.1 (KCNJ8) and SUR1 (ABCC8) subunits. Under higher magnification, the immunostaining for Kir6.2 (KCNJ11) exhibited a cytoplasmic labeling that was more intense at the level of the Golgi apparatus along the whole epididymis. A similar pattern was observed for SUR2 (ABCC9), although in the latter case, the Golgi labeling appeared to be region specific. Spermatozoa in epididymal tubules from rodents also immunostained for Kir6.2 (KCNJ11) and SUR2 (ABCC9). Western blot analysis of epididymal total protein and crude membrane extracts from adult and prepubertal rats confirmed the presence of Kir6.2 (KCNJ11). SUR2 (ABCC9) protein expression was detected in adult epididymal extracts. Furthermore, RT-PCR established the presence of Kir6.2 (KCNJ11) and SUR2 (ABCC9) mRNA in prepubertal and adult mouse epididymis. Indirect immunofluorescence also documented the presence of Kir6.2 (KCNJ11) and SUR2 (ABCC9) in the epididymal epithelium, as well as in spermatozoa, of canine, feline, bovine, and human origin. These data demonstrate the presence of the K(ATP) channel subunits, Kir6.2 (KCNJ11) and SUR2 (ABCC9), in epididymal epithelial cells and spermatozoa from several mammalian species. Although their physiological roles need to be fully characterized, it is tempting to propose that such types of K(++) channels might be involved in protein secretion and fluid-electrolyte transport occurring along the epididymal epithelium, leading to spermatozoa maturation.

Full Text

Full text is available at the source.

View full text ↗

KATP Channel Subunits Are Expressed in the Epididymal Epithelium in Several Mammalian Species1

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief