Cytochemistry of the Gonadotropic Hormones

Abstract

DESCRIBING the histological demonstration of mucin after periodic acid, McManus¹ states that a positive reaction is given, inter alia, by "certain pituitary cells" and "the colloid of the pituitary stalk". According to Chow², the follicle-stimulating and luteinizing fractions of the anterior pituitary secretion are glycoproteins, and Evans et al.³ confirm that the former contains 10·3–13·1 per cent carbohydrate and 8 per cent glucosamine. According to K. Meyer‘s classification, it is thus a mucoprotein, that is, it contains more than 4 per cent hexosamine. Furthermore, Gurin⁴ has shown that chorionic gonadotropin is also a mucoprotein, containing galactose (10–12 per cent) and hexosamine (5–6 per cent) as an integral part of its molecule, and Gey et al.⁵ have demonstrated the production of this hormone by cytotrophoblast cells in tissue culture. On the contrary, Fraenkel-Conrat et al.⁶ have shown that the growth-hormone fraction of the pituitary contains only 0·25 per cent sugar and less than 0·9 per cent glucosamine.