Testicular compensatory hypertrophy in the unilaterally adrenalectomized lizardMabuya carinata (Schn.)

Unilateral adrenalectomy in recrudescent and breeding phases of the reproductive cycle caused atrophic changes in the ipsilateral testis, shown by inhibition of spermatogenic and steroidogenic activity of the ipsilateral testis. The contralateral testis showed compensatory hypertrophy. Unilateral adrenalectomy in regressing and quiescent phases of the reproductive cycle did not induce compensatory hypertrophy in the contralateral testis although there were atrophic changes in the ipsilateral testis.     

Plasma, testicular, and adrenal cortex levels of androgens in the perinatal period and determination of neonatal hypertestosteronemia in guinea pigs]

The perinatal period is characterized in the male faetus and new-born Guinea-Pig by a prenatal increase in testis testosterone and by a neonatal peak in plasma testosterone. This transient rise in plasma testosterone is testis dependent and light dependent at birth.     

Seasonal plasma testosterone variations in the stone marten]

Plasma testosterone levels change with annual sexual cycle of the stone marten. Very low during the decrease and the quiescence of the testis, it rises during the testis onset and reaches a maximal peak during the co?t period (May to July).     

Thymectomy modifies androgenizing effects of a testis transplant during critical period for neuroprogramming

Summary Thymectomy simultaneous with transplantation of a syngeneic testis from a littermate to Fischer 344 rats ameliorated the androgenizing effects of the testis transplant on ovarian morphology at 90 days of age.Supported by a Morseman Fellowship, NIH grants HD07097, AM21137 and NSF-RIAS grant SER77-06922.     

Characterization and localization of the rat,mouse and human testicular phosphatidylethanolamine binding protein

A cytosolic 23kDa protein was initially puified from bovine brain and shown to bind phosphatidylethanolamine. Later, it was also characterized in rat and human brain, and it is now known to be widespread, having been found in numerous tisues in several species. Here, we report the high level of mRNA and phosphatidyl ethanolamine binding protein expression in rat testis and to a lesser extent mouse testis. In human testis, although it was not detectable by Northern blot analysis, the mRNA was shown be present when PCR amplificatin was performed. Immunohistochemical experiments revealed that the testicular phosphatidylethanolamine binding protein (tPBP) is principally expressed in the elongated spermatids of both rat and mouse testis. This finding, and the association of tPBP with cellular membranes, suggest its possible implication in membrane remodelling during spermatid maturation.     

Influence of an injection of chorionic hormone (HCG) on the accumulation of testicular fluid following ligature of the vas deferens in adult Wistar rats]

Using the weight gain of the testis after efferent duct ligation, we have measured the testis fluid secretion. A single injection of HCG to Rats before, at the time or after the ligation leads to three types of effects: no effect which can be explained by the metabolisation of the hormone: a positive and/or a negative one. If the stimulating action of HCG remains unexplained, it must be related with ether anaesthesia. It seems likely that the decrease of testicular fluid secretion may represent the fundamental action of HCG upon the exocrine function of the testis, but the mecanism by which this action occurs remains to be solved.     

The effect of luteineizing hormone on chicken testis and pineal gland uptake of 32P.

The glandular uptake of radioactive phosphorus (32P), administered carrier-free, was used as an endpoint for the study of the effects of luteinizing hormone (LH) on the testis and pineal gland of 3-, 10- and 13-day-old White Leghorn cockerels. Pineal uptake of 32P of the 13-day-old birds decreased and testis uptake of 32P increased following LH treatment. Maximum effects were observed when 20 mug LH was administered 4.0 h before autopsy. Although testis uptake of 32P increased following LH treatment in 3- and 10-day-old cockerels, pineal uptake of 32P remained unchanged.     

Inhibition of post-hemicastration hypertrophy of the remaining testis by testosterone or aqueous testicular extract treatments in the young rat]

In the 10 day old hemicastrated Rat daily injections of testosterone (total doses of 0.04 to 4 mg/Rat) or of proteinaceous extract of Rat testis (4 mg/Rat) inhibit compensatory hypertrophy of the remaining testis. Both testosterone and testicular proteinaceous extract could be involved in the growing processes of the testis, locally or by means of modification of gonadotropin secretion. Results have been analysed by covariance analysis to eliminate the influence of body weight variations.     

Compensatory hypertrophy of the leydig cells in hemiorchidectomized adult rats

Summary Hemiorchidectomy in adult rats results in hypertrophy of the Leydig cells in the remaining testis. The other parts of the testis appear to be unaffected. Supported by the Swedish Medical Research Council (project 12X-05935) and the Harald Jeansson and Magn Bergvall Foundations.     

Influence of temperature and gonadal steroids on the testis composition inRana esculenta

Summary Male frogs at 28°C show an increase in the testis weight and a decrease in its protein content. At 15°C and 4°C the testis lipids increase. Testosterone administration nullifies the low temperature-induced changes in the testis.We are thankful to Prof. G. Chieffi for his criticism. Work done under the C.N.R.-financed finalized project Biologia della Riproduzione.     

Penetration of melanocytes from embryonic Japanese quail peritoneum into associated embryonic avian gonads,grown on chicken chorioallantoic membrane

Summary After association on chorioallantoic membrane (CAM) of an embryonic bird testis with pigmented peritoneum from a Japanese quail embryo, numerous melanocytes penetrate in its interstitial tissue. If, instead of a testis, an ovary is transplanted under similar conditions, then the melanocytes may be found in the medulla or between the secondary sex cords at the rim of the ovary.The author is very grateful to Prof.L. Vakaet, R. U. C. A. Antwerp, for his valuable suggestions, and to MissC. Vaniioecke for her technical assistance.     

The effect of guanethidine treatment of testicular blood flow and testosterone production in rats

Testicular blood flow was measured by means of Xenon-133 clearance in control rats and rats treated with guanethidine for 3 weeks. Plasma and testis testosterone concentrations were also measured, and the effect of hCG-treatment was examined. No difference in testicular blood flow between the control group and the guanethidine-treated group was found. However, in guanethidine-treated rats, plasma and testis testosterone concentrations after hCG-treatment were significantly decreased. The results may indicate that adrenergic nerves are involved in the regulation of Leydig cell function.     

The effect of guanethidine treatment of testicular blood flow and testosterone production in rats

Summary Testicular blood flow was measured bymeans of Xenon-133 clearance in control rats and rats treated with guanethidine for 3 weeks. Plasma and testis testosterone concentrations were also measured, and the effect of hCG-treatment was examined. No difference in testicular blood flow between the control group and the guanethidinetreated group was found. However, in guanethidine-treated rats, plasma and testis testosterone concentrations after hCG-treatment were significantly decreased. The results may indicate that adrenergic nerves are involved in the regulation of Leydig cell function.     

Molecular mechanisms in male determination and germ cell differentiation

Sex determination and gametogenesis are key processes in human reproduction, and any defect can lead to infertility. We describe here the molecular mechanisms of male sex determination and testis formation; defects in sex determination lead to a female phenotype despite the presence of a Y chromosome, more rarely to a male phenotype with XX chromosomes, or to intersex phenotypes. Interestingly, these phenotypes are often associated with other developmental malformations. In testis, spermatozoa are produced from renewable stem cells in a complex differentiation process called spermatogenesis. Gene expression during spermatogenesis differs to a surprising degree from gene expression in somatic cells, and we discuss here mechanistic differences and their effect on the differentiation process and male fertility.Received 23 January 2004; received after revision 30 March 2004; accepted 6 April 2004     

Effect of cyproterone acetate on the testis and epididymis of the lizard,Psammophilus dorsalis (Gray)

Summary The effect of cyproterone acetate (CPA) on the testis and epididymis of the lizard,Psammophilus dorsalis has been studied. Treatment with CPA affects spermatogenesis and steroid metabolism in the testis. It also causes regression of the epididymis and a decrease in steroidogenic enzyme activity.Acknowledgments. We wish to thank Prof. M.R. Rajasekarasetty for his encouragement, Dr K.V. Rao, Nagpur, for a generous gift of cyproterone acetate, Dr V.B. Nadkarni, Dharwar, for permitting the use of his cryostat, Sri B.M. Sekharappa for his technical assistance and UGC, New Delhi for their financial help to one of us (GRS).     

Effect of cyproheptadine hydrochloride on spermatogenesis.

Administration of cyproheptadine hydrochloride (5 mg/kg/day) to old rats for 48 days stimulated spermatogenesis. It also initiated spermatogenesis in the abdominal testis of unilaterally cryptorchid rats after a 15-day treatment.     

Seasonal variations in the sexual activity of the male genet (Genetta genetta L.)]

The Genet testis shows a spermatogenic activity throughout the year. The plasmatic androgen level presents two periods where the values are higher; one in spring the other in autumn. The spring testosterone rise co?ncides with a mating period.     

Connexin 43 a check-point component of cell proliferation implicated in a wide range of human testis diseases

Gap junction channels link cytoplasms of adjacent cells. Connexins, their constitutive proteins, are essential in cell homeostasis and are implicated in numerous physiological processes. Spermatogenesis is a sophisticated model of germ cell proliferation, differentiation, survival, and apoptosis, in which a connexin isotype, connexin 43, plays a crucial role as evidenced by genomic approaches based on gene deletion. The balance between cell proliferation/differentiation/apoptosis is a prerequisite for maintaining levels of spermatozoa essential for fertility and for limiting anarchic cell proliferation, a major risk of testis tumor. The present review highlights the emerging role of connexins in testis pathogenesis, focusing specifically on two intimately interconnected human testicular diseases (azoospermia with impaired spermatogenesis and testicular germ cell tumors), whose incidence increased during the last decades. This work proposes connexin 43 as a potential cancer diagnostic and prognostic marker, as well as a promising therapeutic target for testicular diseases.     

Biological and biochemical characterization of a new isolate of baboon Papio papio endogenous type C virus]

A new strain of Baboon Papio papio endogeneous type C virus was isolated from the testis of an animal of this species. The strain was characterized biochemically and biologically. It presents a host-range different from that of the prototype strain of the same virus.     

Structural differences between somatic H2B and testis-specific TH2B histones of the rat

Testis-specific histone TH2B from rat testis showed a very similar tryptic map to somatic H2B from rat liver, indicating a common evolutionary origin. However, 5 peptide differences were detected between the 2 proteins, and the amino acid compositions of these distinctive peptides were determined.