Density and distribution of connexin 43 in corpus cavernosum tissue from diabetic and hypogonadal patients with...

Altered expression of connexin 43 (Cx43) has been postulated to be involved in the development and progression of various diseases including erectile dysfunction (ED). The aim of this study was to determine whether distribution and density of the gap junction protein Cx43 are altered in human corpus cavernosum (HCC) tissue samples derived from diabetic or hypogonadal patients with ED compared to those from normal subjects.

HCC tissue sections derived from normal, diabetic and hypogonadal subjects were fixed in 4% formaldehyde, embedded in paraffin and immunostained with a monoclonal mouse anti-rat Cx43 antibody. Cx43 density was expressed as the cumulative number of gap junction plaques per unit area of tissue corrected for number of 4',6-diamidino-2-phenylindole, dihydrochloride-labeled smooth muscle cells (dots per unit area corrected for number of cells).

The distribution of Cx43 plaques in smooth muscle was not affected in tissues derived from diabetic or hypogonadal subjects with ED compared with those from normal subjects. However, the number of Cx43 plaques was significantly reduced in HCC tissues derived from diabetic or hypogonadal subjects (73 ± 8% and 68 ± 11% of normal, respectively), indicating reduced Cx43 gap junctions in diabetic and hypogonadal subjects with ED.

Cx43 density in the HCC was diminished in tissue samples derived from diabetic or hypogonadal patients with ED compared to tissue samples from normal non-diabetic subjects. This marked decrease in Cx43 gap junction channels may contribute to attenuated gap junction function and to diminished erectile physiology.