Demonstration of NADPH-diaphorase (NO-synthase) in sebaceous glands of the mammalian integument, with remarks on the glandular capillary net.

The study demonstrates weakly to strongly positive reaction staining for NADPH-diaphorase/NO- synthase in the peripheral cells of sebaceous glands in the hairy skin of domesticated mammals. Additionally, the structure of the blood capillary system surrounding these glands is better elucidated. The results obtained are discussed in view of a modulatory action of NO generated by these enzyme activities, implying a direct influence of this substance on the contractile elements of gland-associated blood capillaries. In this way, a simple and self-regulatory mechanism to couple blood flow and glandular metabolism can be proposed.