Abstract
In view of preceding observations that injections of anterior pituitary glands of cattle cause a marked stimulation of the thyroid gland in guinea pigs, 1 leading to a loss of weight by the animals 2 and to an increase in the basal metabolic rate, 3 it was of interest to investigate the effects of such extracts on the carbohydrate metabolism.
Artundo and Mazzocco 4 found no change in the glycogen reserves of white rats after injections of fresh rat hypophysis in saline. Eitel and Loeser 5 have reported studies on guinea pigs, using anterior pituitary extracts containing thyroid stimulating hormone. They noted a fall in liver glycogen, reaching minimal values in 11 days, with a slow increase subsequently. They report no change in muscle glycogen. Our results are somewhat different in certain respects. We likewise used guinea pigs, which had served for the large majority of experiments carried out by Loeb and Siebert. 6 Male guinea pigs (190-200 gm.) kept under optimal conditions were used in all experiments. The extract was that used previously in this department. 7 Injections were made intraperitoneally with sterile precautions. The animals were killed 24 hours following the last injection and glycogen determined by a modification of the Pflüger method, 8 blood sugars after Shaffer and Somogyi. 9 Two or more animals were employed for each interval recorded and all glycogen determinations were made in duplicate. The points in the accompanying graphs represent averages.
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