Search Results

You are looking at 1 - 6 of 6 items for

  • Author: PAMELA JONES x
Clear All Modify Search
Free access

PAMELA JONES and H. JACKSON

A recent publication has demonstrated the usefulness of Japanese quail in the detailed investigation of male antifertility chemicals (Jones, Kominkova & Jackson, 1972). The present study describes the effect on quail fertility of various dose levels of two compounds, busulphan (Myleran) and cyclohexane-1,4-diol dimethanesulphonate. Because of the established antispermatogonial actions of these substances in the rat, it was anticipated that an estimate of the duration of spermatogenesis in the avian species would emerge from the present work.

The fertility procedure adopted for these experiments has recently been described (Jones et al., 1972). Myleran, suspended in arachis oil, was administered to groups of four male birds as a single intraperitoneal dose or daily for 5 consecutive days. Cyclohexane-1,4-diol dimethanesulphonate (Jackson, 1971) was administered orally on 5 consecutive days in the same

Free access

PAMELA JONES and H. JACKSON

Summary.

A test system involving fertilization in vitro of Xenopus laevis gametes was developed to study the effects of various chemosterilants on toad spermatozoa. The subsequent development of fertilized eggs indicated that effective concentrations and times of exposure were considerably greater than those likely to be achieved with antifertility doses to rodents. Low concentrations of tretamine and ethyleneurea on Xenopus spermatozoa produced high yields of abnormal embryos, whereas other epididymal sterilants active in the rat (trimethylphosphate and α-chlorhydrin) were ineffective in very high concentration. Differences between results in vitro and in vivo may be due to environmental variations or indicate an action by certain compounds on epididymal function in rodents rather than a direct action upon spermatozoa.

Free access

H. JACKSON, C. MARION JACKSON and PAMELA JONES

For the most part, the antifertility actions of non-steroidal chemicals in male rats do not appear directly to involve the endocrine system (Jackson, 1970). In this species, administration of ethylenedimethanesulphonate (EDS) is accompanied by a temporary involution of both the ventral prostate and the seminal vesicles (Cooper & Jackson, 1970). This observation naturally led to an investigation of how far the antispermatogenic and antifertility actions of this compound involved the endocrine system, particularly the production and secretion of androgen. Treatment with EDS also inhibits the spermatogenic process in the mouse (Cooper & Jackson, 1970), in Japanese quail (Jones, Kominkova & Jackson, 1972) and in the parasitic worm, Schistosoma mansoni (Davies & Jackson, 1970).

After a single dose of the compound (75 mg/kg intraperitoneally), rats were sterile by Week 2 and remained thus for about 8 weeks

Free access

Denise E. Bu'Lock and Pamela Jones

Unit of Reproductive Pharmacology, Department of Pharmacology, University of Manchester, Manchester M13 9PT, U.K.

Ethane 1,2-dimethane sulphonate (EDS: MeSO2.OC2H4O.SO2Me) is a non-steroidal antifertility agent (Cooper & Jackson, 1970). In the rat a single i.p. dose of 75 mg/kg inhibits the production of testosterone by the testis (Bu'Lock & Jackson, 1971/72), the effect being maximal by 7 days after injection and completely overcome in 6-9 weeks (Bu'Lock & Jackson, 1975). While testicular steroidogenesis is depressed, serum and pituitary levels of LH are raised (Morris & Jackson, 1975), suggesting that failure of the testis to produce testosterone is accompanied by, if not actually due to, inability to respond to LH in the normal manner by increasing testosterone formation.

Small quantities of LH or HCG (< 1 ng) stimulate the production and release of cyclic adenosine 3′,5′-monophosphate (cAMP) and of testosterone by the testis in

Free access

PAMELA JONES, EVA KOMINKOVA and H. JACKSON

Summary.

The effects of several compounds of established antifertility action in male rodents have been investigated in male quail.

A short period of infertility soon followed administration of oral doses of triethylenemelamine and trimethylphosphate. Triethylenemelamine, aziridinyl urea and ethylenedimethanesulphonate by the intraperitoneal route led to infertile egg production for several weeks.

Differences between rats and quail regarding effective dose and length of sterility are discussed.

Free access

Pamela Jones, H. Jackson and M. H. S. Whiting

Summary.

Niridazole is an effective schistosomicidal compound which, at lower dose levels, affects schistosome gonads. Its antifertility and possible mutagenic effects after various courses of oral treatment were compared in mice, rats and Japanese quail (Coturnix coturnix japonica). In all three species the meiotic stage of spermatogenesis was particularly affected. In mice the highest dose rate (five daily doses of 100 mg/kg) produced sterility during the 4th week. Rats were more susceptible, the compound producing prolonged and, in some animals, permanent sterility against which HCG treatment offered no protection. In quail only a brief phase of sterility occurred. Niridazole appears to be non-mutagenic since dominant lethal mutations were not produced in dose-response studies. Minimal changes in testis histology occurred in the mouse, but in rats severe damage persisted even in animals which had recovered their fertility.