Adenohypophyseal cytology of chemically and surgically thyroidectomized cockerels.

Reproductive traits and histology of the adenohypophysis were studied in adult White Leghorn cockerels after surgical thyroidectomy or .1% propylthiouracil (PTU) food supplementation. Both treatments caused hypothyroidism as judged by a marked reduction in plasma thyroxine levels, a decrease in resting metabolic rate values, an increase in liver and adipose tissue weights, and a marked elevation in the alcianophilic cell population in the adenohypophysis. Both the PTU-treated and thyroidectomized birds demonstrated reduced testes and comb weights. However, although thyroidectomy was found to increase the number of PAS-positive cells in the adenohypophysis, the PTU treatment reduced them. This phenomena is discussed.