title: In vitro effects of insulin on macromolecular events in newt limb regeneration blastemata.
abstract: This work provides data demonstrating a stimulatory effect of insulin on macromolecular events occurring in cultured regeneration blastemata and demonstrates a synergistic interdependence between nerves and insulin in newt limb regeneration. The current experiments provide evidence for the following: (1) Insulin is paramount for expression of the mitogenic effect of nerves on cultures blastemata. (2) Insulin stimulates the incorporation of (3H)uridine into the acid-insoluble fraction of blastemal homogenates, but it does not alter the turnover rate of incorporated labeled uridine. (3) Insulin also stimulates the incorporation of 35SO4 and (3H)leucine into both chondroitinase-sensitive and chondroitinase-resistant blastemal proteoglycans. (4) Insulin increases the uptake of radiolabeled precursors by the blastemata, namely, (3H)leucine, (3H)uridine, 35SO4, (3H)alpha-aminoisobutyrate, and (3H)2-deoxy-D-glucose. The importance of insulin in the regulation of newt limb regeneration is discussed.
mesh_terms: D000818:Animals; D002810:Chondroitinases and Chondroitin Lyases; D005121:Extremities / Q000502:physiology*; D007328:Insulin / Q000494:pharmacology*; D008938:Mitosis / Q000187:drug effects; D011134:Polysaccharides / Q000096:biosynthesis; D011509:Proteoglycans / Q000096:biosynthesis*; D012313:RNA / Q000096:biosynthesis; D012038:Regeneration / Q000187:drug effects*; D012455:Salamandridae
chemical_list: D007328:Insulin; D011134:Polysaccharides; D011509:Proteoglycans; D012313:RNA; D002810:Chondroitinases and Chondroitin Lyases