The human Na,K-ATPase alpha 4 isoform is a ouabain-sensitive alpha isoform that is expressed in sperm.

The Na,K-ATPase generates electrochemical gradients across the plasma membrane that are responsible for numerous cellular and physiological processes. The active Na,K-ATPase is minimally composed of an alpha and a beta subunit and families of isoforms for both subunits exist. Recent studies have identified a physiological role for the rat Na,K-ATPase alpha4 isoform in sperm motility.

Parotid gland metastasis from renal cell carcinoma.

Objective: To discuss the diagnosis and management of metastatic renal cell carcinoma presenting as a parotid mass by studying such cases.

Study Design: Retrospective review.

Methods: Identification of 24 previously reported cases of renal cell carcinoma metastatic to the parotid gland in the English language literature and an analysis of a total of 25 patients including our case.