The fine structure of the basal lamina in the lizard pituitary gland

A report is presented of the fine structure of the basal lamina of cells bordering sinusoids in the skink pituitary gland. The basal lamina, which also lines the sinusoidal membrane, is made up of two bands, a thin lighter band which runs parallel to the cell membrane, and a much wider, denser, and highly branched band which at certain locations is attached to the thin band. The thick band sends regularly spaced branches into the subjacent connective tissue. In most sections these branches appear as parallel, unbranched bars, but in some locations they interconnect to form a highly complex reticular pattern. It is surmised that the basal lamina of these cells must consist of a highly structured lattice which looks and possibly acts like a sponge mat in absorbing and retaining fluid crossing into and from the cells.