title: An investigation of LH pulsatility in burned men by bioassay and radioimmunoassay.
abstract: LH pulsatility studies were performed in six burned patients by removing blood samples at 10 min intervals over a 6 h period. All samples were assayed for LH by bioassay (B-LH), LH by radioimmunoassay (I-LH) and testosterone. Mean serum testosterone concentrations of the burned patients were low (6.7 +/- 1.6 nmol/l). I-LH levels were lower than B-LH in all samples. Frequency of bioactive or immunoreactive pulses as well as mean B-LH and I-LH concentrations were similar to previously published data from normal men examined in the same laboratory. The mean biological activity of LH (expressed as the ratio of B-LH to I-LH, the B:I ratio) was lower in burned subjects (1.9 +/- 0.1) than previously reported in normal men. The B:I ratios of burned men were lower (p less than 0.01) at pulse peaks than at nadirs (1.8 +/- 0.1 vs 2.0 +/- 0.1) and an increase in serum testosterone concentration did not follow an LH peak. Serum testosterone concentrations did not cross-correlate with B-LH or I-LH. This contrasts with the findings in normal subjects where the B:I ratios have been found to be higher at pulse peaks than at nadirs and an increase in serum testosterone concentration follows a pulse peak and serum testosterone cross-correlates with B-LH and I-LH. LH secreted in a pulse peak in normal men may contain a particularly biologically potent form of the molecule but this may not be the case in burned men.
authors.affiliation: Department of Medicine, Southern General Hospital, Glasgow, UK.
authors.forename: C G
authors.initials: CG
authors.lastname: Semple
authors.forename: R
authors.initials: R
authors.lastname: Mitchell
authors.forename: S
authors.initials: S
authors.lastname: Hollis
authors.forename: W R
authors.initials: WR
authors.lastname: Robertson
mesh_terms: D000328:Adult; D001681:Biological Assay; D002056:Burns / Q000097:blood*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D011673:Pulsatile Flow; D011863:Radioimmunoassay; D012016:Reference Values; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D007986:Luteinizing Hormone