HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/3/R788    most recent 00125.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Canniff, K. M. Articles by Moore, M. C. Search for Related Content PubMed PubMed Citation Articles by Canniff, K. M. Articles by Moore, M. C.

DEVELOPMENTAL PHYSIOLOGY AND PREGNANCY

Glucagon secretion and autonomic signaling during hypoglycemia in late pregnancy

¹Diabetes Research and Training Center, Departments of ²Molecular Physiology and Biophysics and ³Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee

Submitted 21 February 2006 ; accepted in final form 22 March 2006

We examined net pancreatic norepinephrine (NE) spillover, pancreatic polypeptide (PP) release, and the decrement in C-peptide to identify factors involved in the blunted counterregulatory glucagon response in pregnancy. Conscious pregnant [pregnant hypoglycemic (Ph); 3rd trimester; n = 8] and nonpregnant [nonpregnant hypoglycemic (NPh); n = 6] dogs were studied during insulin-induced (12-fold basal insulin concentrations) hypoglycemia (plasma glucose 3.1 mM). Additional dogs were studied during hyperinsulinemic euglycemia [nonpregnant euglycemic (NPe), n = 4; pregnant euglycemic (Pe), n = 5; plasma glucose 6 mM]. Arterial glucagon concentrations declined similarly in NPe and Pe. Areas under the curve (AUCs) of the changes in glucagon and epinephrine were seven- and threefold greater in NPh than Ph (P < 0.05 between groups for both). Glucagon secretion fell below basal in NPe, Pe, and Ph but rose significantly in NPh. C-peptide declined 0.25 ± 0.06, 0.12 ± 0.11, 0.28 ± 0.05, and 0.13 ± 0.02 ng/ml in NPe, Pe, NPh, and Ph, respectively (P < 0.05, NPh vs. Ph). AUCs of NE spillover were 516 ± 274, 265 ± 303, 506 ± 94, and –63 ± 79 ng, respectively (P < 0.05, NPh vs. Ph). The AUC of PP release was approximately threefold greater in NPh than Ph (P < 0.05) but not different between euglycemic groups. The current evidence strongly suggests that the blunting of glucagon secretion during insulin-induced hypoglycemia in pregnancy is related to generalized impairment of a number of different signals, including parasympathetic and sympathoadrenal stimuli and altered sensing of circulating and/or intraislet insulin.

pancreatic polypeptide; norepinephrine; epinephrine; hypoglycemic counterregulation; C-peptide

This article has been cited by other articles:

				C. C. Connolly, T. Papa, M. S. Smith, D. B. Lacy, P. E. Williams, and M. C. Moore Hepatic and muscle insulin action during late pregnancy in the dog Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R447 - R452. [Abstract] [Full Text] [PDF]