Rat luteal cells in tissue culture: a technique for obtaining primary cell culture without enzymatic dissociation.

A technique for obtaining isolated luteal cells without any prior enzymatic dissociation of the rat corpus luteum (CL) has been developed. With a view to obviate any kind of chemical/biophysical trauma to the cells the latter were obtained following simple migration of cells from small pieces of chopped up CL (8-10 day old) put in culture. The cells started migrating in progressively increasing numbers from these tissue pieces within 24 hr leading to monolayer formation by day 10-12 of culture. The cells were found to grow under the described conditions for 35 days without any exogenous hormonal supplementation. The technique is being utilized for characterization of different cell types of the rat CL of pregnancy and the regulatory mechanisms involved in their metabolic function and/or regression.

Long-term regulation of male fertility by norethisterone enanthate 'epididymal' implants: effect on libido and fertility of rabbits.

Bilateral insertion of silastic capsules releasing 38-44 micrograms norethisterone enanthate/24 h into the epididymal fat-pads was found to induce complete azoospermia leading to infertility in adult male rabbits 8 weeks after insertion of the progestin implants. The treatment did not exert any inhibitory effects on the libido and sexual behaviour of the animals as judged by objective parameters of mating. Further, the failure of the hormone-releasing implants was not found to exert any adverse effects on the embryos and pregnancy as indicated by the delivery of normal pups to females mated with implant-bearing males 3 weeks after the insertion of 'epididymal' implants.

Effect of intramuscular norethisterone enanthate on compensatory ovarian hypertrophy in the rat.

Norethisterone enanthate (N.E.) administered in repeated intramuscular doses was found to bring about by and large a dose-related inhibition of compensatory ovarian hypertrophy (COH) which follows after the surgical removal of one ovary in adult rats. The relative inhibition in the responsiveness of the remaining ovary to compensatory gonadotrophic stimulation leading to the COH was of the order of 14.2, 19.0, 26.3, 25.0 and 42.0% with 0.25, 0.50, 1.0, 2.0 and 4.0 mg doses of N.E., respectively. The ED50 was calculated to be of the order of 7.0 mg. There was no effect of the treatment on the weight of the pituitary at any dose, whatsoever. However, the treatment was found to induce a significant increase in the weight of the uterus and the adrenals at higher doses (2.0 and 4.0 mg). The possibility of delineating the antigonadotrophic activity of activity of 'N.E.' from its contraceptive potential, vis-a-vis the dose employed, is discussed.

Effect of chronic local administration of norethisterone enanthate on the testes of adult rat.

Silastic implants containing crystalline Norethisterone Enanthate (NE) inserted into the epididymal fat-pads unilaterally were found to bring about a drastic reduction (P smaller than 0.01) in the size and weight of the testis six weeks after implant insertion on the side bearing the progestin implant. The ipsilateral (treated side) testis, caput and cauda epididymis and the vas deferens showed either a complete absence of spermatozoa or occasional few immotile and decapitated sperms. In contrast, the smears obtained from the contralateral testis and the corresponding epididymal segments and the vas showed a population of entirely normal and motile spermatozoa. There was apparently no effect on the epididymis as the ipsilateral epididymis was almost similar (weight-wise) to that of the contralateral side. The results suggested an apparently local effect of NE implants inserted into the epididymal fat pads. The feasibility of the approach for long-term fertility regulation in males is discussed.