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Biomedical subjects

G Chieffi

Publications and source records attributed to G Chieffi.

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

Impact of socio-sexual conditions on the epididymis and fertility in the male mouse.

The influence of previous sexual experience and subsequent differential housing on the epididymis and fertility index was studied for male Swiss albino cc mice. Among animals with previous sexual experience those having a high epididymal beta-glucuronidase activity showed a high fertility index and vice versa. The reproductive potential of animals without previous sexual experience was reduced by housing in high-density groups and in isolation. The results show that previous sexual experience, individual housing and group volume may influence the reproductive potential of male mice.

Animals↗
PubMed1981

Role of eyes and pineal gland in melanophore response in the green frog. Rana esculenta.

The studies suggest that complete inhibition of MSH liberation from the pars intermedia is brought about in response to the receipt of photic cues through the eyes and, possibly, by the pineal gland. The punctuate condition of epidermal melanophores is brought about by the inhibition of MSH liberation alone, whereas the punctuate condition of dermal melanophores is brought about by the inhibition of MSH liberation and the liberation of melanin aggregating substance from the pineal gland in response to photostimulation.

Adaptation, Biological↗
PubMed1979

Effects of castration, 5 alpha-dihydrotestosterone and cyproterone acetate on enzyme activity in the mouse epididymis.

The influence of castration, androgen replacement therapy and cyproterone acetate on the activity of beta-glucuronidase, acid and alkaline phosphatases and glucose-6-phosphate dehydrogenase was studied in the caput, corpus and cauda epididymidis of the mouse. The results add further evidence that the epididymis is not uniform but has regional differences in activity. Thus beta-glucuronidase was found to be androgen-dependent only in the cauda epididymidis, whereas glucose-6-phosphate dehydrogenase was under androgenic control in the caput epididymidis. The response of alkaline and acid phosphatases to castration and to androgen replacement was different in different segments.

Acid Phosphatase↗
PubMed1978

Annual variations in the total lipid and protein content of the liver, fat body, ovary and plasma of the female frog (Rana esculenta L.).

The concentrations of lipid and protein in the ovary, fat body, liver and plasma of the female frog (Rana esculenta L.) were found to exhibit marked seasonal variations. There was an interesting correspondence between the depletion of lipid in the plasma and fat body and an increased level of lipid in the ovary. It would appear that oestrogenic steroids stimulate and increase the concentrations of lipids in the plasma, whereas pituitary gonadotrophins influence the uptake of lipids by ovarian tissue for vitellogenesis.

Animals↗
PubMed1975

The function of fat bodies in relation to the hypothalamo-hypophyseal-gonadal axis in the frog, Rana esculenta.

In this study the authors have tried to furnish experimental support for the importance of fat bodies in the normal functioning of the hypothalamo-hypophyseal-gonadal system of the male frog, Rana esculenta. These experiments have shown a hypothalamo-hypophyseal control of the mobilization of fat body contents, directly involved in the control of testicular activity. Furthermore it is proposed that the fat body contents are released into the testis through direct vascular contacts between the two organs. We suggest that the A1 cells (lactotrophs) and/or B2 cells (FSH-gonadotrops) of the pars distalis gonadotropins are incapable of stimulating the testis in the absence of fat bodies. In the light of these results a scheme has been put forward showing the position of fat bodies in the hypothalamo-hypophyseal-gonadal axis of the frog.

Adipose Tissue↗
PubMed1975

Biological activity of some steroidal compounds in the adult and larval frogs.

Four steroids were tested for their biological activity, using the sex-steroid-dependent redevelopment of the secondary sex characteristics in adult frogs and gonadal sex differentiation in larval frogs as end points. In adult frogs, 19-norprogesterone and 6-chloro-17alpha-hydroxy-4, 6-pregnadiene-3,20-dione had antiandrogenic and antiestrogenic effects. 2alpha, 17alpha-Dimethyl-DHT and 2alpha-methyl-DHT were potent androgens and effective antiestrogens. In the larval frogs, all four compounds had a masculinizing effect upon the undifferentiated gonads.

Animals↗