Beta-endorphin and calcitonin in human semen.

The levels of beta-endorphin (beta-E) and calcitonin were estimated in 36 samples of seminal plasma from semen of normospermic, oligozoospermic, and azoospermic origins and in pools of isolated sperm. The mean levels in plasma calculated for all samples examined were 192 +/- 224 pg/ml for beta-E and 754 +/- 397 pg/ml for calcitonin. The amounts in sperm were as follows: for beta-E in pools with sperm counts of 0.1-10 x 10(6)/ml, 157.2 +/- 99.7 pg/10(8) and 27.9 +/- 23.6 pg/ml protein; in pools of greater than 10-30 x 10(6)/ml, 71.2 +/- 41.5 pg/10(8) and 6.5 +/- 1.2 pg/mg protein; in pools of greater than 30-200 x 10(6)/ml, 24.9 +/- 9.7 pg/10(8) and 61 +/- 1.9 pg/mg protein. For calcitonin the amounts were: 501.2 +/- 170.8 pg/10(8) and 27.4 +/- 21.5 pg/mg protein, correspondingly. It was suggested that beta-E and calcitonin present in seminal plasma are synthesized mostly in a compartment of the male reproductive system. The high cellular beta-E and calcitonin levels would be involved in the process of motility through their effect on calcium transport.