Lectin histochemistry of the human testis

The oligosaccharide sequences of glycoconjugates and the nature of the sacc haride linkage were investigated in normal human testes by means of lectin histochemistry studies, at light and electron microscopy levels. Reaction t o WGA was intense in the seminiferous epithelium and interstitium. MAA show ed light reactivity ill all cell types of the human seminiferous epithelium , the lamina propria and Leydig cells. UEA-I lectin labelled the lamina pro pria intensely and the seminiferous epithelium and Leydig cells slightly. A slight reaction to AAA was found ill the seminiferous epithelium and in Le ydig cells. ConA was labelled in Sertoli cells, germ cells and Leydig cells . The reaction to GNA lectin was similar although less intense. PNA labelli ng was slight in Sertoli cells, spermatogonia, and Leydig cells, and more i ntense ill spermatocytes, spermatids and peritubular cells. Reaction to DSA was intense in the seminiferous epithelium and Leydig cells. HPA labelled all cell types in the seminiferous epithelium and Leydig cells slightly, an d labelled peritubular cells intensely. SEA lectin showed a strong reaction in spermatids and a slight reaction in the lamina propria. The reactions t o SNA, LTA, and DBA were negative in all testicular cell tyres. After beta- elimination pre-treatment, MAA, UEA-I, AAA, PNA, DSA, HPA and SEA reactions were all negative. Endo F/PNGase digestion suppressed reactivity to ConA y GNA. Staining for WGA decreased with Endo F/PNGase digestion and also afte r beta-elimination. Desialization increased reactivity to PNA, SEA and HPA lectins. These results indicate that the terminal sequences of oligosacchar ide side-chains in spermatocytes and, principally, in spermatids are: fucos e, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, Gal1,4GlcNAc, Neu5AcGalNAc and GalNAc tin O-glycosylated proteins); mannose till N-glycosylated prote ins) and GlcNAc tin both protein types). A sialic acid residue is added to galactose and GalNAc residues. Present findings also indicate that Sertoli cell glycoproteins are similar to those of spermatids, and that the termina l sugar residues in Leydig cells are GlcNAc, fucose, mannose, Neu5Ac2,3Gal1 ,3GalNAc, Gal1,3GalNAc, and Gal1,4GlcNAc. The It lectin pattern of the lami na propria suggests the presence of GlcNAc, galactose, fucose and GalNAc.