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The level of endothelin‐like immunoreactivity in seminal fluid correlates positively with semen volume and negatively with plasma gonadotrophin levels
Author(s) -
Hammami Muhammad M.,
Haq Afrozui,
AlSedairy Sultan
Publication year - 1994
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1994.tb03932.x
Subject(s) - medicine , endocrinology , semen , endothelin 1 , plasma volume , testicular volume , plasma levels , biology , hormone , andrology , receptor , secondary sex characteristic
Summary OBJECTIVE The newly discovered vasoactive peptides, endothelin 1, 2 and 3, and their receptors are widely distributed in various non‐vascular tissues. Recent studies have suggested the presence, as well as possible regulatory roles, of endothelins at several levels of the pituitary‐gonadal axis. We determined the level of endothelin‐like immunoreactivity in the seminal fluid and examined its possible correlation with routine semen parameters or plasma levels of FSH, LH or testosterone. DESIGN Prospective study in a tertiary care centre. PATIENTS Ninety‐one men attending infertility clinics for male factor, female factor or both. MEASUREMENTS Endothelin‐like immunoreactivity was determined in seminal fluid using two radioimunoassays, ET1–21 that measures endothelin and ET‐1,2 that measures both endothelin and big endothelin. In addition, the levels of FSH, LH and testosterone as well as routine semen parameters were determined. RESULTS Sperm density ranged from 0 to 315 times 10 8 with a mean (±SD) of 28.5 times 10 8 (±48 times 10 8 ) sperm/ml and the percentage of motile sperm ranged from 0 to 85% with a mean of 16% (±20.5%). Mean levels of FSH ( n = 33), LH ( n = 35) and testosterone ( n = 35) were 6.4 ± 4.9 IU/I, 3.5 ± 2.8 IU/I and 21 ± 9.4 nmol/l, respectively. Mean ET1‐21 level ( n = 91) was 81 ± 16.5 pmol/l, and mean ET‐1,2 level ( n = 33) was 630.5 ± 143 pmol/l. There were significant correlations between the levels of ET1–21 and ET‐1,2 ( r = 0.37, P = 0.04), ET1–21 and FSH ( r = −0.5, P = 0.006), ET1–21 and LH ( r = −0.46, P = 0.01), and ET1–21 level and semen volume ( r = 0.23, P = 0.03). Mean level of ET1–21 or ET‐1,2 was significantly lower in patients treated empirically with clomiphene citrate or gonadotrophins ( n = 34) compared to untreated ( n = 52) patients ( P = 0.04). CONCLUSIONS We conclude that in human seminal fluid (1) endothelin‐like immunoreactivity that is specific for active endothelin (ET1–21) represents about 13% of the total immunoreactivity; (2) inactive big endothelin or its N‐terminal derivative(s) may account for most of the immunoreactivity; (3) the production/secretion of endothelin may be inhibited by LH and/or FSH; and (4) endothelin level correlates positively with seminal fluid volume.