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J. P. BENNETT

Summary.

A quantitative agar gel zone electrophoretic method has been used to establish comparatively at one time and under as similar conditions as possible, the relative amounts and mobilities of the seminal plasma proteins of the bull, ram, boar and rabbit.

A striking species specificity was shown in the electrophoretic patterns. The number of components, relative mobilities, glycoprotein and lipoprotein contents and the relative amounts of the protein components varied markedly according to the species.

There was little variation between the electrophoretic patterns of seminal plasma collections obtained from five animals in any one species and the variations in pattern between the collections from any one individual animal was also small.

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J. P. BENNETT

Successful induction of ovulation in some cyclic adult and prepubertal species of Old World monkey, Macacca mulatta, has been reported by Van Wagenen & Simpson (1957) and by Simpson & Van Wagenen (1962), using injected extracts of monkey pituitaries and human postmenopausal gonadotrophins respectively. In these studies ovulation was determined by histological examination of the ovary and no attempts were made to recover freshly ovulated eggs from the Fallopian tubes. Efforts to induce ovulation by injection of monkey pituitary were unsuccessful.

The first experiments are now reported of inducing ovulation, with injections of pregnant mares serum (pms) and human chorionic gonadotrophin (hcg), in a species of New World monkey, Saimiri sciureus, the common squirrel monkey, as a step towards obtaining pregnancies in this species by artificial insemination.

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J. P. BENNETT

The first successful attempt to collect semen from monkeys was reported by Mastroianni & Manson ( 1963) using adult macaques. A monophasic, alternating current was applied through two surface electrodes, one around the base of the penis, the other against the ventral aspect of the glans near the frenulum. The method was successful in eight out of eleven monkeys. Weisbroth & Young (1965) later described the use of a rectal probe to stimulate ejaculation of semen in several species of Old World macaques.

A specially designed rectal probe has now been used to stimulate ejaculation of semen in a species of New World monkey, Saimiri sciureus (the common squirrel monkey), in order to collect spermatozoa for artificial insemination of adult female monkeys after induction of ovulation with gonadotrophins (Bennett, 1967a, b). The male squirrel monkey is a comparatively small primate weighing about 900 g and having a body length of about 30 cm. It adjusts well to captivity and is easy to handle.

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J. P. BENNETT

Summary.

Future production of entirely new contraceptives will proceed more slowly than in the past due to the lack of basic knowledge in reproductive physiology, the increasingly restrictive government drug-regulatory controls for new contraceptives and the lack of sufficient and suitable research support by industry and government. Some of these restrictions towards discovery of new contraceptives may be overcome by the WHO Expanded Program if they can avoid the mistakes of similar government research support groups. This programme holds out some hope for quickly bringing suitable contraceptive technology to the underdeveloped nations of the world where the major population control problem lies.

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K. E. KENDLE and J. P. BENNETT

Summary.

The position of mouse eggs in the reproductive tract was determined following the administration of various doses of reserpine by the intraperitoneal route on Day 1 of pregnancy. High doses caused arrest of egg transport, while lower doses caused delay. The possibility that reduced hormone secretion is responsible was investigated by administration of ovarian, hypophysial and thyroid hormones. The failure of these various treatments to reverse the reserpine-induced arrest of egg transport suggests that alterations in hormone secretion are not the primary cause of the arrest.

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J. P. BENNETT and H. M. DOTT

Summary.

Epididymal contents were collected from a bull with an epididymal fistula and from normal bulls after slaughter. When this material was diluted with seminal plasma collected by means of an artificial vagina from either the bull with a fistula or from normal bulls, the impedance change frequency due to the motility of the spermatozoa was reduced as was the length of time for which it could be detected. The fluid obtained from the penis of the bull during electric stimulation with a low voltage did not produce the same effect. The latter fluid had no fructose, a low protein content and a different pattern of inorganic ion concentration from the seminal plasma; the agar gel electrophoresis pattern was also different.

Dilution of epididymal contents with normal seminal plasma did not affect the morphology of spermatozoa or their response to differential staining. Furthermore, neither these characteristics nor the impedance change frequency were affected by a mild degree of temperature shock produced by sudden cooling from 20° C to 10° C.

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J. P. BENNETT and K. E. KENDLE

Reserpine is a tranquillizer and hypotensive agent (Plummer, Earl, Schneider, Trapold & Barret, 1954) which has been shown to influence uterine smooth muscle activity (Clegg, 1963). The present study was undertaken to investigate the effects of reserpine upon the rate of transport of eggs down the Fallopian tube of the mouse.

A stock solution was made by dissolving 300 mg reserpine and 375 mg citric acid in 6 ml benzyl alcohol with gentle warming. A volume of 15 ml ofTween 80 was added. After cooling, the final volume was adjusted to 100 ml with distilled water, and the solution protected from light. This reserpine stock solution was diluted with distilled water immediately before use to adjust the dose volume to 10 ml/kg body weight.

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J. P. BENNETT and L. E. A. ROWSON

Summary.

A technique of cannulation of the epididymis of the bull with the subsequent establishment of a patent fistula is described, which allows for the repeated collection of epididymal spermatozoa and secretions from the living animal.

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K. E. KENDLE and J. P. BENNETT

Summary.

The position of eggs in the reproductive tract of the mouse was determined following the administration of several drugs with effects on smooth muscle and tissue amines. Of the compounds examined, only chlorpromazine and tetrabenazine were effective in causing a reduction in the rate of egg transport in the oviduct. Both compounds, like reserpine, caused hypothermia in the mouse. Further investigation showed that the arrest of egg transport can be prevented by housing animals at elevated environmental temperatures. The implications of these findings in relation to the physiology of the mouse oviduct are discussed.

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CECILIA LUTWAK-MANN, J. C. BOURSNELL and J. P. BENNETT

Summary.

(I) Solutions of labelled ions 32PO4 3-, 35SO4 2-, 24Na1+, 42K1+ and 131I,1- were administered parenterally to pregnant rabbits on Days o to 12 of gestation (the day of mating being designated o). Several experiments were also done with adult oestrous rabbits. Measurements of radioactivity were made at 45 min after ion injection. Results were expressed as the proportion, X IO-6, of the total radioactive ion injected, found present per mg tissue or fluid, fresh weight. (2) The following findings were made in normal, pregnant rabbits: (a) in the free-lying 6-day blastocyst values for all ions were low, that for PO4 3- being lowest, and, moreover, they showed a marked degree of divergence; this contrasted with the much higher and closely grouped values in the I2day foetus; (b) in the fluid withdrawn from the blastocoelic cavity on Days 7 to IO values for PO4 3-, SO4 2- and Na1+ rose to a peak on Day 8, and declined on Days 9 and IO; (c) in the endometrial secretion all ion values greatly exceeded those in the free-lying blastocysts and in the blastocyst fluid, and remained relatively stable during Days 6 to 12 of pregnancy; (d) placental tissue retained more than twice the amount of PO4 3- found in the inter-implantation segments of the endometrium, a phenomenon absent or much less prominent with the other ions; (e) all ions except K1+ showed higher values in the endometrium and secretion of non-pregnant rabbits than in the progestational phase of pregnancy; (f) exceptionally high PO4 3- values were typical of the endometrium and secretion on Days 2 and 3 of gestation. (3) The incorporation of 32PO4 3- was studied more extensively than that of the other ions, in pregnant rabbits treated with oestrogens (stilboestrol, oestradiol benzoate), certain purine analogues (6-mercaptopurine, 8-azaguanine) and trypan blue.

In pregnant rabbits which had received single doses of stilboestrol or oestradiol benzoate 36 hr before 32PO4 3- injection, there was a depression in PO4 3- uptake on Days 3 and 4 in the endometrium and secretion; this was in disparity with the enhanced ion uptake evident from Day 5 onwards. In placental tissue a rise above normal occurred only on Day 7, and was followed by a progressive decline from Day 8 onwards, being most marked in the foetal placenta at 12 days. Retention of PO4 3- was distinctly increased in the 6-day blastocysts; on the other hand, very low values were recorded in 12-day foetuses. In the blastocyst fluid the peak at 8 days was obliterated owing to higher values on Days 7, 9 and 10.

Suitably timed treatment of pregnant rabbits with mercaptopurine, azaguanine, or trypan blue, produced no changes in ion incorporation in the endometrium or secretion. Values for the 6-day blastocyst remained unaltered. A small but distinct depression in ion retention in the 12-day foetus and placenta followed treatment alike with the purine analogues and trypan blue. (4) In the cervix or vagina no changes were observed in ion uptake analogous to those recorded for endometrial mucosa and secretion. (5) The significance of this experimental approach to the problem of blastocyst-uterine relationships is discussed with respect to the functional organization in the pre-implantation blastocyst, the diurnal shifts in the uterine environment, the differential response to oestrogen treatment of uterine tissues depending upon their nature and the period of gestation, and the impaired ability of damaged foetus or placental tissue to retain ions entering from the maternal bloodstream.