期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：12
页码：3478-3482
DOI：10.1073/pnas.70.12.3478
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Glucagon and insulin are first detectable at the onset of rat pancreas organogenesis. Initially, the specific activity of glucagon is approximately 100-fold higher than that of insulin. At this early stage, endocrine storage granules, similar to [α] granules, are identifiable in electron micrographs. The granule characteristics, as well as the relative hormone levels, suggest that the early population of differentiated endocrine cells is in fact composed of glucagon-producing (A) cells. This high level of glucagon is present in the embryo much earlier than the metabolic processes thought to be controlled by this hormone. Moreover, glucagon-producing cells may be the first endocrine cells to differentiate. Other known endocrine products accumulate later, during the terminal stages of organogenesis. These observations suggest that glucagon may have a regulatory function in early embryogenesis.
