Action of cholinergic drugs on accumulation of TPMP+ on human spermatozoa.
Neurotransmitters or antagonists with nicotinic- or acetylcholine-type receptors were utilized to measure the accumulation of the radiolabeled lipophilic cation triphenylmethylphosphonium (TPMP+) on the plasma membrane of human sperm. Washed sperm incubated in the presence of TPMP+ in a low-K+ or high-K+ medium were allowed to take up the cation to a steady state (i.e., 20 min at 37 degrees C). The difference between TPMP+ in each incubation medium was inserted in the Nernst equation yielding a resting membrane potential of -69 +/- 2 mV. The addition of nicotine or acetylcholine to the low-K+ and high-K+ medium induced a hyperpolarization of 17% and 20%, respectively. In the presence of propranolol the membrane potential decreased by 44%. The association of nicotinic or acetylcholine receptor on human sperm or adrenergic beta-receptor blocking agent may alter the ionic permeability of the membrane, possibly due to hyperpolarization or depolarization.
Calzada
L
L
Unidad de Investigación Clinica en Enfermedades Endocrinas, Hospital de Gineco-Obstetricia Luis Castelazo Ayala, Tizapán, México.
Wens
M A
MA
Salazar
E L
EL
D000109:Acetylcholine / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009538:Nicotine / Q000494:pharmacology; D009861:Onium Compounds / Q000032:analysis*; D010277:Parasympathomimetics / Q000494:pharmacology*; D011188:Potassium / Q000493:pharmacokinetics; D011433:Propranolol / Q000494:pharmacology; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D014320:Triphenylmethyl Compounds / Q000032:analysis*
D009861:Onium Compounds; D010277:Parasympathomimetics; D014320:Triphenylmethyl Compounds; C011561:triphenylmethylphosphonium; D009538:Nicotine; D011433:Propranolol; D000109:Acetylcholine; D011188:Potassium