Peripheral Endocrine Glands. I. The Gastroenteropancreatic Endocrine System and the Thyroid Gland

The Comparative Anatomy of Islets

“…For the first time, we see islets that are encapsulated by a collagenous-type connective tissue to exclude them from the exocrine tissue (Falkmer and Ostberg 1985). Glucagon, insulin, and somatostatin immunoreactive cells are localized in the islets, but few or no PP cells are found (Hansen et al 1987;Youson 2007) (Fig. 2).…”

Stimulatory effect of thyroid hormones improves larval development and reproductive performance in alligator gar (Atractosteus spatula) and spotted gar (Lepisosteus oculatus)

“…). In addition, the paucity of data on thyroid physiology in ancient fish (Youson ) makes further description of the role of TH in lepisosteid larval development especially important, and may provide alternatives to improve larval robustness and survival. Furthermore, hormonal manipulation may reduce costs and increase productivity of lepisosteid culture.…”

“…Such fish may be expected to exhibit characteristics of thyroid function different from salmonids due to differences in temperature optima, nutrient requirements, or salinity tolerance (Moon et al 1994). In addition, the paucity of data on thyroid physiology in ancient fish (Youson 2007) makes further description of the role of TH in lepisosteid larval development especially important, and may provide alternatives to improve larval robustness and survival. Furthermore, hormonal manipulation may reduce costs and increase productivity of lepisosteid culture.…”

Lampreys: Biology, Conservation and Control

“…These latter cells were, at that time, referred to as members of the amino precursor uptake and decarboxylation (APUD) series. Since the lamprey has no stomach, it seems more correct to use the term entero-pancreatic (EP) endocrine system (Youson and Al-Mahrouki 1999;Youson 2000Youson , 2007. Since the lamprey has no stomach, it seems more correct to use the term entero-pancreatic (EP) endocrine system (Youson and Al-Mahrouki 1999;Youson 2000Youson , 2007.…”

“…The morphogenesis of the lamprey EP system, and mainly the islet organ, has been reported and reviewed in great detail over the past 20 years (Youson and Elliott 1989;Youson and Cheung 1990;Youson and Al-Mahrouki 1999;Youson 2000Youson , 2007 and the reader is referred to these publications for an expansive report on both the ontogeny and the phylogenetic significance. Here we provide only the highlights of the findings during this very active period of investigation.…”