Effect of Azadirachta indica leaves on rat spermatozoa.

Histochemical studies and SEM observations on the morphological changes in the head of the spermatozoa in general, and the acrosome in particular, in A. indica treated rats are reported. In the treated rats change in the shape and size of the sperm head, with a dorso-ventral constriction of the middle region of the sperm head i.e., between the anterior and posterior regions was observed. It was rather difficult to differentiate the outer acrosomal and outer plasma membranes. A decrease in the perforatorium or sub-acrosomal material, post nuclear cap and the nuclear material near the basal plate at the base of the sperm head were also observed. The results suggest that the effects are probably due to androgen deficiency and a general disturbance in carbohydrates or polysaccharides located in the sperm head, caused by the antiandrogenic property of the leaves of A. indica.

Peritoneal fluid modulates the sperm acrosomal exocytosis induced by N-acetylglucosaminyl neoglycoprotein

The effect of peritoneal fluid (PF) on the human sperm acrosome reaction (AR) was tested. Sperm was pre-incubated with PF and the AR was induced by calcium ionophore A23187 and a neoglycoprotein bearing N-acetylglycosamine residues (NGP). The AR induced by calcium ionophore was inhibited 40 percent by PF from controls (PFc) and 50 percent by PF from the endometriosis (PFe) group, but not by PF from infertile patients without endometriosis (PFi). No significant differences were found in the spontaneous AR. When the AR was induced by NGP, pre-incubation with PFc reduced (60 percent) the percentage of AR, while PFe and PFi caused no significant differences. The average rates of acrosome reactions obtained in control, NGP- and ionophore-treated sperm showed that NGP-induced exocytosis differed significantly between the PFc (11 percent) and PFe/PFi groups (17 percent), and the ionophore-induced AR was higher for PFi (33 percent) than PFc/PFe (25 percent). The incidence of the NGP-induced AR was reduced in the first hour of pre-incubation with PFc and remained nearly constant throughout 4 h of incubation. The present data indicate that PF possesses a protective factor which prevents premature AR

Reaçäo acrossômica na exploraçäo de infertilidade masculina em fecundaçäo in vitro / Place of acrosomal reaction in the exploration of male infertility in in vitro fertilization

O acrossoma, vesícula de origem golgiana, tem um papel essencial no desenvolvimento da fecundaçäo, tanto in vivo com in vitro. Neste artigo estudaram diferentes métodos de induçäo da reaçäo cromossômica (RA). Os indutores como o líquido folicular, a progesterona e o cálcio iônico permitem a exploraçäo da dinâmica da RA e a análise dos espermatozóides aptos a realizar esta RA. Este trabalho mostra o interesse destas exploraçöes nos casos de infertilidade masculina em Reproduçäo Assistida.

Induction of acrosome reaction in fresh and frozen-thawed bovine spermatozoa by platelet activating factor.

In vitro capacitation has been induced in fresh and frozen spermatozoa of Karan Swiss (KS) and Karan Fries (KF) crossbred cattle by using a phospholipid-platelet activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine). The capacitation was monitored by examining acrosome reaction (AR) and motility at various levels of platelet activating factor (PAF) and at the end of each incubation time. On an average, with the increase in incubation time, there was a gradual decrease in motility and increase in acrosome reaction in both fresh as well as frozen spermatozoa. As PAF level increased, the motility of fresh sperms decreased and their acrosome reaction increased dramatically. However, in frozen-thawed semen, the motility remained almost the same and increase in AR of frozen spermatozoa was not pronounced. PAF level of about 100 microM was observed to be most optimum as at this level AR improved significantly without much loss of motility.

Effect of TEST-yolk upon sperm acrosome reaction

Espermatozoides humanos mantenidos en el buffer Test-yolk muestran un aumento de la frecuencia de fusión con los oocitos desnudos de hamster cuando se los compara con los espermatozoides recién eyaculados. Por consiguiente, en este trabajo, hemos estudiado la cinética de la reacción acrosomal y fertilización mediante el empleo de espermatozides humanos recíen obtenidos versus espermatozoides mantenidos en el Test-yolk. En esta forma procuramos determinar si la frecuencia de fertilización estaba relacionada a la de la reacción acrosomal. Las muestras de sememn fueron divididas en dos alicuotas, una fresca (control) y la otra mantenida por 48 horas a 4-C en el buffer Test-yolk (experimental). Los espermatozoides de cada muestra fueron examinados cada dos horas para: a) evaluar la incidencia de la reacción acrosomal estudiada con el microscopio electrónico de barrido y b) la habilidad para fusionarse con oocitos denudados de hamster. Los resultados mostraron que, en función del tiempo de incubación, ocurre un aumento en el procentaje de reacción acrosomal en ambos grupos, control (cero a 28.3%) y el experimental (5 a 27.8%). Se encontró también que la incidencia de la reacción acrosomal no presenta diferencias significativas en ambos grupos. Con respecto al porcentaje de fertilización el grupo experimental mostró valores más altos (p < 0.05) cuando se lo comparó al grupo control. Estos reusltados sugieren que el aumento del porcentaje de fertilización de los espermatozoides mantenidos en le Test-yolk no está asociado a un aumento de la reacción acrosomal sino probablemente a una mejor eficiencia en la fusión de las membranas de las gametas

Solubilizacion de la membrana del espermatozoide humano con n-dodecil sarcosinato de sodio: I.accion del detergente / Solubilization of the membrane human spermatozoa: I. action of the detergent

Espermatozoides humanos fueron lavados con PBS y tratados com n-dodecil sarcosinato de sodio (Sarkosyl). El insoluble remanente estaba compuesto por cabezas, cuyas colas fueron cortadas a la altura del cuello o del segmento intermedio y cuyas membranas no sufrieron mayores danos, estando el acrosoma intacto y por pequenos corpusculos que podrian ser acrosomas aislados. Los resultados indican que la accion del detergente es de dos tipos claramente diferenciados: a)diseccion del espermatozoide con separacion de la cola y b)disolucion del mismo dejando el acrosoma intacto. El residuo conserva actividad inmunologica e inmunobiologica