Sperm Protection Research Articles

Pregnancy‐Associated Plasma Protein‐A and Placental Protein 5 in Human Ovarian Follicular Fluid

By sensitive and specific radioimmunoassays PAPP-A and PP5 were detected in follicular aspirates obtained from women undergoing ovarian hyperstimulation for oocyte harvest prior to in vitro fertilization and embryo transfer. Follicular and pregnancy-derived PAPP-A were immunologically and physicochemically indistinguishable. Similarly, pregnancy- and nonpregnancy-derived PP5 were immunologically indistinguishable. However, in addition to the 18- and 36-K species, a larger species having a molecular size greater than 140K was found in the follicular fluid. Mean follicular PAPP-A and PP5 concentrations were 727 mIU/L and 1376 mAU/L, respectively, with no significant correlation between follicular PAPP-A, PP5, and steroid concentrations. There was, however, a significant but negative relationship with follicular volume. Preliminary in vitro studies indicated that both proteins were synthesized by granulosa cells in preparation for follicular rupture. Follicular PP5, like antithrombin III, interacted reversibly with heparin and thrombin affinity matrices, suggesting a potential biological role as a follicular anticoagulant, whereas PAPP-A, a specific and potent inhibitor of leukocyte elastase, contributes to the maintenance of proteolytic homeostasis and the protection of spermatozoa and embryo against proteolytic attack originating from the maternal leukocytes.

Semen extenders for artificial insemination in the American alligator

Semen was collected post-mortem from 19 male alligators ( Alligator mississipiensis) by dissection of the genitalia. In 12 of 13 wild alligators, two of two farmed alligators, and three of four zoo alligators adequate numbers of spermatozoa (>1 × 10 9 total cells) were collected for semen preservation and artificial insemination studies. Semen extended in solutions containing a combination of egg yolk and milk, rather than either of these constituents alone, was superior for long-term liquid storage. The addition of either penicillin with dihydrostreptomycin, or gentamycin, in combination with yolk and milk enhanced the longevity of sperm cells as compared to maintenance of motility in solutions without antibiotics. Both glycerol and DMSO were detrimental to sperm cell motility. Dimethyl sulfoxide (DMSO) was less detrimental than glycerol. Semen frozen by pelleting on dry ice resulted in loss of motility of all but 0–2% of spermatozoa in all extenders tested. Neither DMSO nor glycerol was beneficial in protecting sperm cells during freezethaw compared with extenders not containing these compounds.

An ultrastructural comparison of soft and hardened spermatophores from the crayfish Pacifastacus leniusculus Dana

The spermatophore of the crayfish Pacifastacus leniusculus consists of two main parts: a sperm mass composed of sperm embedded in a dense fibrillar matrix and an acellular wall which surrounds the sperm mass and is formed from secretions produced in the vas deferens. Following extrusion from the male, the spermatophore wall, which is initially soft and sticky, undergoes a hardening process. In this study, the structure of the spermatophore walls of unextruded (soft) and hardened spermatophores were compared using light and electron microscopy. The wall of the unextruded spermatophore is composed of three concentric layers: a thin primary spermatophore layer which directly surrounds the sperm mass; a thick middle layer composed primarily of electron-dense, spherical granules; and a thick outer layer formed from a dense globular secretion. The primary spermatophore layer and outer globular layer are positive for carbohydrate with the periodic acid – Schiff method. Following extrusion and hardening, the walls of spermatophores showed several structural changes. These are (i) division of the middle granular layer into a compact inner region and a highly reticulated outer region; (ii) the loss of the outer globular layer; and (iii) the formation of a thickened ridge along one side of the spermatophore wall. The thickened ridge is fibrillar in structure and is believed to be derived from a structural modification of the outer globular layer. No structural modifications in the primary spermatophore layer were observed. We interpret these observations to indicate that the outer globular layer functions in attachment of the spermatophore to the female and the middle layer is involved in spermatophore hardening and sperm protection during storage.

Cold Shock and Various Extenders Effects on Physical and Chemical Characteristics of Ram Sperms

AbstractThe protective effect of egg yolk citrate, egg yolk skimmed milk, and egg yolk lactose extenders on the sperm cell against freezing injury was studied using Ossimi and Rahmani rams. Advanced motility, dead and coiled tail percentages of fresh spermatozoa did not differ significantly between the two breeds. Freezing caused a highly significant increase in dead and coiled tail percentages of spermatozoa diluted with various extenders. Unsaponifiable matter of fresh spermatozoa of both breeds contained various hydrocarbons and sterols with C 26, C 24 and cholesterol being the basic compounds. The unsaponifiables distribution could be used to characterize the spermatozoal origin. Changes in total sterols/total hydrocarbons ratios of the unsaponifiables were occurred after freezing of both breeds using the three extenders. Cholesterol content of fresh spermatozoa and the changes in physical properties of spermatozoa of both breeds indicated that the freezability of Ossimi semen was better than that of Rahmani. Also, the changes occurred in physical properties and total sterols/total hydrocarbons ratios showed that egg yolk lactose extender was better than egg yolk skimmed milk and egg yolk citrate extenders for sperm protection against freezing injury.

Equal Protection for Sperm

Equal Protection for Sperm

Toxic Effect and Action of Dead Sperm on Diluted Bovine Semen

The toxic effect of dead sperm on diluted bovine semen and the modifying effect of certain compounds on this toxicity were investigated.Toxicity is associated with an amino aeid oxidase which becomes active only after death of sperm. A metabolic product of this enzyme, peroxide, is responsible for the toxic effect of dead sperm. The enzyme is active against aromatic amino acids only. Its toxic effect is enhanced by increasing egg yolk, inhibited by ethylenediaminetetra-acetate (EDTA), and eliminated by catalase. Inhibition of toxicity by EDTA is by protection of sperm against deleterious effects of peroxide and not by inhibition of the enzyme. The enzyme is inhibited by ethyl maleimide indicating active sulphydryl groups. It is labile to heat being inactivated by heating to 90C for 2 minutes. It is also labile to pH 3 and pH 9. An active fraction was obtained from dead sperm by precipitation with 30% acetone. Activity of ejaculated dead sperm is only slightly less than freshly killed sperm. Practical implications are discussed.

The reproductive biology of Sergestes similis (Decapoda, Natantia)

A study was made of the reproductive biology of Sergestes similisHansen from the Santa Barbara Basin off the coast of southern California. It includes investigations of sex ratios, sexual dimorphism, and morphology of the reproductive system. Histological sections of the gonads revealed stages of gametogenesis, as well as an external criterion of sexual maturity in males. Determination of chromosome number and morphology was made using standard karyological techniques. The external genitalia are noticeably adapted for the transfer and maintenance of the spermatophore, and for the protection and transport of sperm during external fertilization. A few aberrant individuals show apparent sex reversal. Based on size-frequency records and internal examination of the gonads, a description of their reproductive cycle for 1967 is presented for specimens from the Santa Barbara Basin.