The molecular type and localization of calcium channels along the nephron are not well understood. In the present study, we assessed the distribution of the recently identified alpha(1G)-subunit encoding a voltage-dependent calcium channel with T-type characteristics. Using a RNase protection assay, alpha(1G)-mRNA levels in kidney regions were determined as inner medulla >> outer medulla congruent with cortex. RT-PCR analysis of microdissected rat nephron segments revealed alpha(1G) expression in the distal convoluted tubule (DCT), in the connecting tubule and cortical collecting duct (CT+CCD), and inner medullary collecting duct (IMCD). alpha(1G) mRNA was expressed in the IMCD cell line mIMCD-3. Single- and double-labeling immunohistochemistry and confocal laser microscopy on semithin paraffin sections of rat kidneys by using an anti-alpha(1G) antibody demonstrated a distinct labeling at the apical plasma membrane domains of DCT cells, CT principal cells, and IMCD principal cells.
|Tidsskrift||American Journal of Physiology: Renal Physiology|
|Status||Udgivet - 2000|
Andreasen, D., Jensen, B. L., Hansen, P. B., Kwon, T. H., Nielsen, S., & Skøtt, O. (2000). The alpha(1G)-subunit of a voltage-dependent Ca(2+) channel is localized in rat distal nephron and collecting duct. American Journal of Physiology: Renal Physiology, 279(6), F997-1005.