Endocrine and sperminogenic testicular function. 7. Relationship between testicular and plasma androgen concentrations in boars of different ages]

Testicular tissue and blood samples (V. spermatica interna) were taken from 32 boars during castration. The animals were of different age groups. Against this background, comparative studies were conducted into the relationships between testicular and plasma testosterone. A very close correlation was found to exist between the androgen values in testicular tissue and those in the blood plasma of V. spermatica interna (r = 0.9795), wich appeared to support the conclusion that by determination of blood plasma the androgen content in the testes can be established with high probability.     

Endocrine and spermatogenic testicular function. 9. Correlations between plasma testosterone and morphometric parameters of the testis in boars of different ages]

Close, statistically fully secured correlations were found to exist in boars, aged between four and four-a-half as well as seven and nine months, between the testosterone content in the blood of the V. spermatica interna, on the one hand, and morphometric parameters essential to quantitative sperm production, on the other (testicular volume, volume of germinativum, overall length of tubules, diameter of tubules, and cell density of the germinal epithelium).     

The effect of different cell concentrations and incubation time of testicular tissue testosterone synthesis

The cells of the testes of mice were enzymatically separated and the amount of Leydig cells was determined in different stages of dispersion and after washing the separated tissue. This amount ranged from 2 to 9%. The largest quantity of Leydig cells (9%) was obtained when separated tubuli were washed. The response of cell suspensions at seven concentrations stimulated by human chorion gonadotrophin (HCG) was tested. Cell suspension concentrations from 5.3 x 10(5) to 1.4 x 10(6) cells/ml were found to be satisfactory. After two to three hours of incubation, the values of testosterone could be used for the determination of the activity of gonadotropic preparations.     

Influence of dimethoate on testicular and epididymal organs, testosterone plasma level and their tissue residues in rats.

The effect of dimethoate at two dosage levels (6.25 and 12.50 mg/kg b. wt.) on male reproduction tissues and their tissue residues in rats were studied. The tested doses were given orally to male rats for 65 consecutive days. Sex organs weight analysis, semen picture, testosterone levels and histopathology of the male genital organs were the criteria used to evaluate the reproductive efficiency of the treated rats. There was a dose-related decrease in the weights of most genital organs and sperm motility associated with an increase in the percentages of dead and morphologically abnormal spermatozoa of treated rats. A decrease in plasma testosterone levels was observed in the treated groups. Histological examination revealed that dimethoate caused testicular lesions characterized by moderate to severe degenerative changes of spermatogonial cells and by partial arrest of spermatogenesis. Sections from liver revealed that the central veins and hepatic sinusoids appeared dilated, with some areas of haemorrhage. The highest concentrations from dimethoate were found in liver and tests and the lowest in skeletal muscle. Dimethoate and its metabolite analog were still present in a detectable concentration 21 days after stopping its oral administration.     

Relationship between testicular transferrin and plasma estradiol-17beta concentrations of dogs with azoospermia and dogs with sertoli cell tumors.

Testicular Transferrin (Tf) and peripheral plasma estradiol-17beta (E2) concentrations were measured in 3 dogs with azoospermia (AZ dogs), 3 dogs with Sertoli cell tumors (SC dogs), and 5 normal male Beagles. The mean Tf concentrations in the testes of the AZ dogs and the affected testes of the SC dogs, and the plasma E2 concentrations in both these groups of dogs were significantly higher than the values in normal dogs (P<0.05, 0.01 and 0.01, respectively). Therefore, excessive E2 secretion by hyperfunctioning Sertoli cells is thought to have caused the azoospermia in the 3 dogs.     

Studies on the endocrine and spermiogenic functions of testes. I. Relationship between the quality of dietary protein and testosterone content in testicular tissue of pubertal rats]

Growing, male Wistar rats were fed for 21 days one of four qualitatively different proteins, as follows: 1. casein and 4% methionine (group K) 2. maize meal and amino acid supplement (group M + As) 3. maize meal alone (group M) 4. casein plus 4% of a 1:3 mixture of methionine and gelatin (group K/G) (These rations constitute a decreasing range of biological activity of the diet.) After 21 days of feeding these rations, the testosterone content per 100 g body weight averaged 80 ng in groups K and M + As, compared with 8 ng in groups M and K/G. Body weight increment averaged 48 g in group K, 40 g in group M + As, 19 g in group M and -9g in group K/G. Total testicular mass averaged 1658, 1730, 1485 and 641 mg in the four groups, respectively.     

The effect of age and season of the year on testicular function in the dog, as determined by histological examination of the seminiferous tubules and the estimation of peripheral plasma testosterone concentrations

The diameter and area of the seminiferous tubules and the thickness of the germinal epithelium was measured in testes removed from clinically normal dogs of different breeds and mixed ages over a 24 month period which were presented for elective castration or euthanasia. Peripheral plasma testosterone concentrations were determined at the same time. There was no effect of the season of the year on the tubular diameter, thickness of germinal epithelium or tubular area. There was evidence of an effect of age upon tubular diameter and thickness of the germinal epithelium. Peripheral plasma testosterone concentrations were significantly higher in summer and autumn than in winter and spring, but age appeared to have no effect.