Search Results

You are looking at 1 - 10 of 17 items for

  • Author: H. SCHINDLER x
Clear All Modify Search
Free access

H. NEUMARK and H. SCHINDLER

Epididymal semen was obtained from rams with a fistula present in the vas deferens (Tadmor & Schindler, 1966). It was deproteinized immediately, and the protein-free clear supernatant evaporated to dryness in vacuo at a temperature not exceeding 55° C. The residue was taken up with about 10 ml water, and the solution thus obtained used for determination of both amines and amino acids.

For the determination of amino acids, the solution was once more dried in vacuo, and the residue taken up with 3 ml 75% ethanol. Two-dimensional chromatograms of two samples were run, using 0·2 ml of the final solution, according to Mizell & Simpson (1961).

For the determination of the amines, the solution was extracted by the method of Yoshinaga, Itoh, Ishida, Sato & Wada (1961), slightly modified (Neumark, 1964).

After three extractions with ethyl

Free access

H. SCHINDLER and A. NEVO

Summary.

Microscopic observations of fowl and bull spermatozoa in thin flat glass cells at rest showed that they inactivated themselves after time intervals that were inversely related to the `amount of motility' of the suspension and directly related to the oxygen and sugar concentrations in the medium. Aeration restored full activity immediately.

It was confirmed that motility of fowl and bull spermatozoa is aerobic obligatory in the absence of a reducing sugar in the medium. Under anaerobic conditions motility was maintained when a reducing sugar was available.

In a thin layer adjacent to the air-liquid interface, motility was maintained by diffusion of oxygen from the air into the suspension, forming distinct zones of quiescence and motility with a sharp boundary between them. The width of the motile zone was found to be in good agreement with theoretical values calculated on the assumptions of constant respiratory rate, independent of oxygen concentration, and of zero oxygen concentration at the boundary.

Inactivation of fowl spermatozoa was accompanied by agglutination in the shape of plait-like `ropes' which formed a network throughout the suspension. The agglutinates were dispersed on mixing and reactivation of the spermatozoa. Inactivation of bull spermatozoa was not accompanied by agglutination of this type.

Microscopic observations of sperm motility and measurement of times of inactivation, in thin flat glass cells, can be used to determine the respiratory rate, anaerobic glycolysis and motility of spermatozoa in one operation.

Carbon dioxide was found to inactivate fowl spermatozoa reversibly.

Free access

D. AMIR and H. SCHINDLER

Summary.

Rates of fructolysis and oxygen uptake were measured in suspensions of ram spermatozoa containing various concentrations of lactate at different pH. It was found that lactate by itself causes a reversible depression of the metabolic rate, the magnitude of the effect being dependent on the lactate concentration.

Free access

H. SCHINDLER and D. AMIR

The effect of different sperm doses on the conception rate has been studied by Salamon (1962), Gancev (1963) and Kareta, Osikowski & Wierzbowski (1966), but without relation to a possible effect of time of insemination. Jones, Martin & Lapwood (1969) and Entwistle & Martin (1972) studied the effect of restricted sperm doses (100 × 106 and 50 × 106 spermatozoa) and, by relating the results to vaginal mucus score, found that the highest conception rate occurred in ewes with a copious, clear or cloudy mucus at the time of insemination. On the other hand, in recent work in this laboratory (Amir & Schindler, 1972), it was shown that with the use of 300 to 500 × 106 freshly ejaculated spermatozoa, single inseminations of ewes were of uniform and high efficiency almost throughout oestrus. The present study was undertaken in order to investigate the possibility that the time

Free access

EUGENIA ALUMOT and H. SCHINDLER

In a study of the composition of the epididymal fluid of rams, attention was given to the fact that nitrogen compounds constitute a great part of the dry matter and that so far seventeen free amino acids have been detected in the fluid (Ch. Neumark, unpublished data). It was therefore deemed of interest to study the enzymes of their metabolism. Two principal transaminases were investigated: glutamic-aspartic transaminase (got) and glutamic-alanine transaminase (gpt). The presence of these enzymes has been established in human, bovine and rabbit seminal plasma (Flipse, 1960; Povoa & Villela, 1960; Gregoire, Rakoff & Ward, 1961), but no report on their presence in the epididymal fluid was found in the literature.

article image

Epididymal fluid obtained from fistulated rams (A. Tadmor & H. Schindler, unpublished information) served for the enzyme determination. For comparison, the enzymatic activity was also investigated in the seminal plasma and blood serum of rams.

The procedure

Free access

D. AMIR and H. SCHINDLER

It is generally accepted that in cattle the conception rate depends upon the time of insemination in relation to the time of ovulation, considering the unequal life-span of the gametes and the time necessary for sperm transport and capacitation (Asdell, 1955). Accordingly, practical recommendations have been put forward as to the time during oestrus when insemination will result in the optimum conception rate (Salisbury & VanDemark, 1961).

Studies made in ewes gave variable results, with the optimum time for insemination coinciding with the first half of oestrus (Sinclair, 1957; Morrant & Dun, 1960; Restall, 1963; Jones, Martin & Lapwood, 1968; Mattner & Braden, 1969), mid-oestrus (Kardymovic, Marsakova & Pavljucek, 1934; Carbonero-Bravo, 1955) or the later stages of oestrus (Anderson, 1941; Restall, 1961; Schindler, Eyal & Volcani, 1961; Steklenev, 1961).

In view of the potential

Free access

D. AMIR and H. SCHINDLER

Summary.

The rates of oxygen consumption and fructolysis were measured in suspensions of washed spermatozoa at concentrations ranging from 1×109 to 7×109/ml. Within that range the respiratory rate was independent of sperm concentration, provided that the oxygen diffusion was adequate. Similarly, the rate of fructolysis under anaerobic conditions and constant pH was not influenced by high sperm densities.

Free access

A. R. LEHRER and H. SCHINDLER

Foreign bodies inserted into the uterine lumen of ewes act as contraceptives (Hawk, 1965, 1967). A sensor used for monitoring uterine contractions in the non-pregnant ewe in vivo should not, therefore, be implanted in the lumen when minimal interference with normal reproductive function is desired. The following experiments were carried out in order to test the possibility of maintaining the capacity to conceive by implanting the sensor in the uterine wall rather than in the lumen.

Dummies were made of perspex in the shape and size of the real pressure transducers which were to be used (Text-fig. 1). The uteri of cycling, non-lactating, Awassi ewes were exposed at laparotomy and incisions about 1 cm long were made on the dorsal wall through the serosa into the myometrium. An additional incision at right angles to the first was made in the myometrium beneath the serosa. Dummies were inserted in

Free access

EUGENIA ALUMOT, Y. LENSKY and H. SCHINDLER

Summary.

Proteins of ram epididymal fluid, seminal plasma, accessory gland fluid and blood serum were fractionated by electrophoresis. Nineteen bands of different mobilities were observed by disc electrophoresis. Immunoelectrophoresis revealed sixteen precipitation arcs in epididymal fluid and seminal plasma and fourteen in blood serum, following absorption with the antiserum against epididymal fluid. These results indicate that most of the epididymal fluid and seminal plasma proteins of the ram have antigens in common with blood serum.

Free access

A. TADMOR, H. SCHINDLER and ORA KEMPENICH-PINTO

Summary.

In nine out of eleven operations, fistulae were established in the vas deferens of rams. This was accomplished by incising the vas deferens and suturing the orifice to a small surgical opening in the dorsal surface of the scrotum, close to the incision through which the vas deferens had been exposed.