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.

The zoapatle XIV--the effect of oral administration of zoapatle upon progesterone plasma levels in pregnant rabbits.

Oral administration of zoapatle aqueous crude extract (ZACE) made from Montanoa tomentosa or frutescens at doses of 5 mg/day from days 3 through 17 of pregnancy in rabbit, did not modify the normal plasma levels of progesterone. Pregnancy and delivery were similar in controls and zoapatle-treated animals.

Capacitation of human spermatozoa by heparin.

Zona-free hamster oocytes were incubated in vitro with human spermatozoa treated with heparin for 5, 10, 20, and 30 min. Sperm penetration was observed 2, 4, and 8 h after insemination. Sperm penetration was successful in 40%, 60%, and 69% of the oocytes treated for 10 min with heparin. Feminine and masculine pronuclei were clearly identifiable. In these samples, 80% of the sperm was alive and there was approximately 68% progress motility. Live sperm were observed for up to 24 h. Since glycosamineglycan sulfates are normally present in the ooplasm, zona pellucida, follicular and uterine fluids, this might suggest a direct participation of heparin in human sperm capacitation.

Efecto de algunas aminas terciarias comunmente empleadas en la clinica sobre la motilidad y la viabilidad espermaticas. / The effect of tertiary amines of common clinical use upon the motility and viability of human spermatozoa

En busca de farmacos con posible accion contraceptiva, se valoro el efecto de cuatro aminas terciarias de amplio empleo en clinica, que son clorpromacina, imipramina haloperidol y verapamil, sobre la motilidad y la viabilidad de los espermatozoides humanos. Las concentraciones requeridas para disminuir en 50 por ciento la motilidad de los espermatozoides a los cinco minutos de incubacion fueron de 130, 120, 200 y 250 nanomolas/ml de medio de cultivo y las concentraciones requeridas para disminuir en 50 por ciento la viabilidad fueron de 170, 350, 240 y 780 nanomolas/ml para clorpromacina, impramina, haloperidol y verapamil respectivamente. La clorpromacina presento la mayor actividad espermaticida, y con el verapamil se observo una accion espermaticida cinco veces menor.Las dosis de estas aminas terciarias que se emplean en la clinica por vias oral o intramuscular y los niveles sanguineos que se obtienen son mucho mas altos que los requeridos para inhibir la motilidad y la viabilidad espermaticas. Se sugiere la posibilidad de emplear estos compuestos en sistemas de liberacion constantes en la vagina (anillos vaginales), tal vez sin efectos colaterales generales indeseables a la vez que conservan su accion contraceptiva local