The Cultivation of the Pituitary of Infantile Rats by the Glass-Rod Technique and the Influence of Grafted Explants on the Growth of Hypophysectomized Hosts

Abstract

ABSTRACT Explanted anterior pituitaries of 13−17-day-old rats survive in watchglasses on glass rods for at least 3 months. In whole expiants of 10−14-day-old animals the posterior lobe (pars nervosa), and probably the pars intermedia as well, survive as long as the anterior lobe. Both the anterior lobe and the pars nervosa survived, when embryo extract was added to the medium, for up to 131 days. Some acidophilic cells, partly degranulated, persist in cultures throughout the whole in vitro life of the explant. Basophils closely resembling the ‘castration cell’ are clearly visible in stained preparations of the explant, but only after 6 to 8 weeks of cultivation. A number of dividing chromophobes have been observed during the first 2 months of cultivations. Anterior pituitaries after cultivation for between 1 and 2 months when grafted into the anterior eye chamber caused young hypophysectomized rats to resume their growth which had been completely arrested. In some explant-transplants the parenchyma of the anterior lobe consists of only one type of cell, namely the chromophobe; in others, some partly granulated acidophils have been found. Basophils have not been observed in transplanted expiants. Anterior pituitaries cultivated in a diluted (liquid) plasma medium retain a remarkably normal appearance for over two months and contain numerous healthy-looking acidophil cells throughout that time. A modification of the glass-rod technique for use with liquid media has been described.