Secretion of epidermal growth factor in parotid saliva in diabetic patients: role of autonomic innervation

Abstract

Parotid saliva was collected over a 12‐min period from 24 insulin dependent diabetic patients with varying degrees of autonomic neuropathy and 12 age and sex matched non‐diabetic controls. Epidermal growth factor (EOF) concentrations in saliva were measured by radio‐immunoassay. The EGF concentrations in diabetics with no autonomic neuropathy or with combined autonomic neuropathy were equivalent but secretion of EGF was significantly elevated at the 6‐and 12‐min periods of collection in diabetic patients with early or established autonomic neuropathy. It is postulated that when parasympathetic autonomic neuropathy is present a relative “over‐activity” of the sympathetic innervation promotes release of salivary EGF. This sympathetic predominance may maintain salivary EGF concentration despite the elevated salivary flow and volume which is associated with parasympathetic autonomic neuropathy.