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) Submit a response Alert me when this article is cited Alert me when eLetters are posted 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 (5) Citing Articles via Google Scholar Google Scholar Articles by Chow, V. T. K. Articles by Phoon, M. C. Search for Related Content PubMed PubMed Citation Articles by Chow, V. T. K. Articles by Phoon, M. C.

TEACHING IN THE LABORATORY

MEASUREMENT OF SERUM LEPTIN CONCENTRATIONS IN UNIVERSITY UNDERGRADUATES BY COMPETITIVE ELISA REVEALS CORRELATIONS WITH BODY MASS INDEX AND SEX

Human Genome Laboratory, Department of Microbiology, Faculty of Medicine, National University of Singapore, Kent Ridge 117597, Singapore

Synthesized mainly in adipocytes, leptin is a peptide hormone that plays a key role in the regulation of body weight and composition. The serum leptin concentrations of 193 Singapore university medical and bioscience undergraduates aged 19–26 yr were measured using a competitive ELISA kit, and their leptin levels were correlated with sex and body mass index (BMI). Mean leptin levels were more than twice as high in females than in males of corresponding weight status, especially among females of healthy weight who exhibited levels that were 5.7 times higher. Overweight individuals generally demonstrated higher circulating leptin concentrations than healthy-weight and underweight participants. The differences in mean leptin levels between underweight and overweight males (P = 0.006), as well as between healthy-weight and overweight males (P = 0.011) were statistically significant. Comparison tests of leptin levels between healthy-weight and underweight females were highly significant (P = 0.001). Highly significant linear correlations between BMI and the logarithm of leptin concentration were observed in the female (r = 0.44) and male (r = 0.36) groups. These results reiterate the impact of gonadal steroids as mediators of the apparent sexual dimorphism in circulating leptin. The findings also corroborate evidence that adiposity determines leptin levels. This laboratory exercise has educational value for undergraduates by determining their BMIs, by alluding to the importance of maintaining healthy body composition, and by emphasizing the molecular mechanisms of body weight regulation and obesity, with special reference to leptin. This practical study also exemplifies the principles and applications of the competitive ELISA technique and integrates certain key concepts of physiology, molecular biology, immunology, and medicine.

Key words: leptin; competitive enzyme-linked immunosorbent assay; body mass index; sex differences; correlation; undergraduates

This article has been cited by other articles:

				R. M. Passos, A. B. Se, V. L. Wolff, Y. K. M. Nobrega, and M. Hermes-Lima Pizza and pasta help students learn metabolism Advan Physiol Educ, June 1, 2006; 30(2): 89 - 93. [Abstract] [Full Text] [PDF]

				M. Peters-Golden, A. Swern, S. S. Bird, C. M. Hustad, E. Grant, and J. M. Edelman Influence of body mass index on the response to asthma controller agents. Eur. Respir. J., March 1, 2006; 27(3): 495 - 503. [Abstract] [Full Text] [PDF]

				M. H. Gillis, S. K. Duckett, J. R. Sackmann, C. E. Realini, D. H. Keisler, and T. D. Pringle Effects of supplemental rumen-protected conjugated linoleic acid or linoleic acid on feedlot performance, carcass quality, and leptin concentrations in beef cattle J Anim Sci, March 1, 2004; 82(3): 851 - 859. [Abstract] [Full Text] [PDF]