Recombinant human insulin-like growth factor-I increases forearm blood flow

Kenneth C. Copeland, K. Sreekumaran Nair

Research output: Contribution to journalArticle

84 Scopus citations

Abstract

Several recent reports have described systemic effects associated with insulin-like growth factor-I (IGF-I) infusions in humans, including dizziness, syncope, unconsciousness, bradycardia, and asystole. Eleven healthy volunteers (10 males and 1 female) underwent brachial arterial and deep forearm venous catheterizations to evaluate the effects of an intraarterial infusion of IGF-I on blood flow. Saline was infused into the brachial artery for 1 h, followed by infusions of recombinant human IGF-I (1.25, then 10 µgrams/kg BW.h) over 2 subsequent 90-min periods. Blood flow across the forearm was determined from dye dilution curves after an infusion of indocyanine green dye (20 mg/h) into the proximal arterial port. The rate of saline infusion had no effect on forearm blood flow. Likewise, the low dose arterial IGF-I infusion had no effect on blood flow, even though deep venous IGF-I concentrations increased slightly (127 ± 37 to 172 ± 19 ng/mL; P = NS). The 10 µgrams/kg.h infusion rate increased deep venous IGF-I concentrations approximately 4-fold above control values (477 ± 80 vs. 150 ± 27 ng/mL, respectively; P < 0.0001), whereas IGF-I concentrations in the peripheral circulation were increased approximately 2-fold (299 ± 50 ng/mL) above control values (P < 0.0001). Arteriovenous glucose differences, peripheral glucose concentrations, and binding protein-3 concentrations were not influenced by either dose of IGF-I. The 10 µgrams/kg.h dose of IGF-I was associated with a 68% increase in forearm blood flow (71 ± 8 vs. 42 ± 6 mL/min, respectively; P < 0.0004). These data suggest that an intravascular infusion of IGF-I results in significant alterations in regional blood flow, which may be related to the observed physiological effects or side-effects associated with its use.

Original languageEnglish (US)
Pages (from-to)230-232
Number of pages3
JournalJournal of Clinical Endocrinology and Metabolism
Volume79
Issue number1
DOIs
StatePublished - Jul 1994

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ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical

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