Key result
Low-dose angiotensin II stimulates human sperm forward velocity, while high doses suppress motility via receptors.
Why the study?
The effects of angiotensins on the motility of highly washed human sperm were not fully characterized.
Angiotensin II directly affects human sperm motility via specific receptors, stimulating forward velocity at low doses and suppressing motility at high doses.
Answers are grounded in this paper and cite their sources.
Angiotensin II may bidirectionally affect sperm velocity in vitro; hypothesis-generating for fertility research, no practice change.
The effects of angiotensins on the motility of highly washed human sperm were examined by multiple exposure photography system. The addition of low doses (0.1-10 ng/ml) of angiotensin II (AT II) stimulated the forward velocity of sperm without increasing the percentage of motility. On the contrary, high concentration (1.0 micrograms/ml) of AT II suppressed the motility. The direct effect of angiotensin I (AT I) on the motility was observed under the presence of SQ 14225, a specific inhibitor of angiotensin I converting enzyme (ACE). At I (0.1-100 ng/ml) gave no influence on the motility, whereas that of high dose (1.0 ug/ml) suppressed the motility in the same manner as the corresponding dose of AT II. The action of AT II on the motility was completely suppressed under the coexistence of saralasin, a specific antagonist against AT II. This fact indicated that the action of AT II on the sperm appeared through the specific receptor on sperm.
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Kaneko et al. (1984) studied this question. Angiotensin II and Angiotensin I was evaluated on Sperm motility and forward velocity. Low doses of angiotensin II stimulated the forward velocity of human sperm without increasing the percentage of motility, whereas high concentrations suppressed motility via specific receptors.
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