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Biomedical subjects

C J Dominic

Publications and source records attributed to C J Dominic.

At least 55 records · Page 3Linked to original sources
PubMed1981

Failure of adrenalectomy to prevent the male-induced pregnancy block (Bruce effect) in mice.

Adrenalectomy failed to prevent the ovoimplantation block that occurs in newly mated female mice following exposure to alien males. No difference in the percentage of pregnancy failure in adrenalectomized females as compared with sham-operated or intact females was noted. It is concluded that the pituitary-adrenal axis is not involved in the Bruce effect and the stress-response does not adequately account for the neuroendocrine changes induced in newly mated females following exposure to alien males that lead to ovoimplantation failure.

Adrenal Glands↗
PubMed1981

Effect of vasectomy on the testis and accessory sex glands of the musk shrew, Suncus murinus L.

The effects of uni- and bilateral vasectomy on the testis and accessory sex glands were studied at intervals up to six months. Vasectomy induced degenerative changes in the seminiferous tubules during the first four months after the operation; thereafter a partial recovery of spermatogenesis was noticed at six months post-vasectomy. Unilateral vasectomy induced degenerative changes only in the ipsilateral testis; the contralateral testis presented normal histology and showed no evidence of compensatory hypertrophy. The Leydig cells, however, remained unaffected in vasectomized shrews. No significant change was found in the concentrations of protein, RNA and DNA in the testis and of fructose in the ampullary gland in uni- and bilaterally vasectomized animals as compared with controls. The absence of any change in the concentration of fructose, weight of the accessory sex glands and histology of the ampullary gland and Leydig cells in vasectomized animals suggests that endocrine functions of the testes are not affected by vasectomy.

Animals↗
PubMed1979

Failure of deodorized males to induce oestrus in the wild mouse.

The ability of female mice to return to oestrus following exposure to males perfumed either with oil of wintergreen or with the commercial perfume, "Kanta" was evaluated. Unisexual grouping of female mice induced anoestrus in all individuals. Oestrus was, however, promptly induced in the majority of unisexually grouped females by exposure to normal males. By contrast, exposure to perfumed males failed to induce oestrus in unisexually grouped females. The results suggest that male urine which is the source of the primer pheromone involved in the induction of oestrus was ineffective because of the masking effect of artificial scents. Hence the unisexually grouped females were unable to perceive the pheromone from males and continued to remain in anoestrus following exposure to perfumed males. The results provide additional evidence in support of the view that the urinary pheromone produced by males induces oestrus in females by acting through olfactory pathways.

Animals↗
PubMed1979

Suppression of oestrus-inducing pheromone production in the Indian field mouse, Mus booduga Gray, by treatment with an antiandrogen.

The effect of cyproterone acetate (CA) on the production of the male-originating oestrus-inducing pheromone in the Indian field mouse, Mus booduga Gray was investigated. The anoestrus induced in regularly cycling females by unisexual grouping was reversed by exposure to intact males. The majority of male-exposed females returned to oestrus within seven days, with a peak on the fourth-day. By contrast, exposure to CA-treated males failed to induce oestrus in grouped females. Since CA is a potent antiandrogen, the inability of CA-treated males to induce oestrus in females is interpreted as due to the depression of the production of the androgen-dependent pheromone. The results provide evidence in favour of the concept that the oestrus-inducing pheromone in the Indian field mouse is associated with androgens either directly or indirectly through some androgen-dependent gland.

Animals↗
PubMed1978

Functional significance of the cells in the pars anterior of the pituitary gland of the musk shrew (Suncus murinus L.).

Seven morphologically and tinctorially distinct types of cells (types 1--7) have been distinguished in the pars anterior of the pituitary gland of the musk shrew (Suncus murinus L.). On the basis of their responses to various experimental stimuli, these cell types were correlated with the secretion of various trophic hormones. Type 1 cells exhibited conspicuous changes after thyroidectomy or inactivation of the thyroid gland and hence appeared to be the source of TSH. Types 2 and 3 cells responded to gonadectomy and administration of androgens, which suggests that they were associated with gonadotrophin secretion. The granules of the type 2, but not the type 3 cells could be extracted with 10% trichloroacetic acid, which may indicate that type 2 and 3 cells secrete FSH and LH respectively. After the administration of either reserpine or oestrogen, the type 4 cells underwent hypertrophy and hyperplasia, which suggests that they were the likely source of prolactin. Type 6 cells, which are distinguishable from type 4 cells by their thinly dispersed erythrosinophilic granulation, showed conspicuous changes after unilateral adrenalectomy, administration of metyrapone or exposure to stress and may therefore be responsible for secretion of ACTH. Type 5 cells tinctorially resembled the somatotrophic cells of other mammalian species and did not respond to any of the experimental treatments used in the present study. It is therefore possible that these cells have a somatotrophic function. The possible significance of type 7 cells has been discussed previously.

Adrenalectomy↗