Chalone Control of Mitotic Activity in Eccrine Sweat Glands

Summary.— In the eccrine glands of mouse footpads mitoses are common in the intradermal ducts, and they also occur in the ampullae. No mitoses were seen in either the gland cell or the intraepidermal ducts. The duct cell mitoses were not inhibited by either the epidermal or the sebaceous gland chalones. However, it was found that human sweat contains an inhibitor of eccrine duct mitosis, which does not inhibit either epidermal of an eccrine gland chalone. In support of this it was found that adrenalin inhibits and adrenalectomy promotes eccrine duct mitosis.