Journal of Andrology

KUOPIO, T.; SAVOURAS, P. OD.; PELLINIEMI, L. J.; HUHTANIEMI, I.T.

doi: 10.1002/j.1939-4640.1989.tb00113.xpmid: 2512272

Newborn rat testis was transplanted under the kidney capsule of adult castrated and uncastrated male rats to develop and characterize a model system for studies on Leydig cell development. Two weeks after transplantation, the number of Leydig cells and the size of their nuclei in the transplants had increased. Secretion of testosterone was indicated by increased seminal vesicle weights and decreased pituitary LH in the castrated host animals. Pituitary FSH content increased significantly in the uncastrated animals with transplants, which suggested production of an FSH‐stimulating factor. Cells with the morphologic features characteristic of fetal‐ and adult‐type Leydig cells were observed in the transplants. The seminiferous tubules with spermatocytes, incipient lumina, and significantly larger average diameters showed more advanced development than those in the normal 2‐week‐old testis. By the present morphologic and functional criteria, the kidney subcapsular transplantation technique provides a suitable model for studies of fetal and adult Leydig cell development.

doi: 10.1002/j.1939-4640.1989.tb00114.xpmid: N/A

JONES, ROBERT E.; PLYMATE, STEPHEN R.

doi: 10.1002/j.1939-4640.1989.tb00115.xpmid: 2531732

To clarify the mechanism of phospholipid synthesis in spermatozoa, fresh human spermatozoa were incubated with labeled fatty acids and 1‐acyl‐lysophosphatidyl choline (LPC) in the presence or absence of coenzyme A (CoASH). Both docosahexaenoic acid and palmitic acid were incorporated into phosphatidylcholine; however, this reaction was absolutely dependent upon the presence of CoASH in the incubation medium. The rate of incorporation of docosahexaenoic acid was 2.7‐fold higher than that of palmitic acid, but more palmitic acid was incorporated into phosphatidylcholine in the absence of LPC. These data provide direct evidence for acyl transferase activity in human spermatozoa and may furnish a mechanism for phospholipid remodeling in sperm membranes. The different incorporation rates of these fatty acids into phosphatidylcholine may be due to the kinetics of the activation step, long chain fatty acid:CoASH ligase (AMP), or the substrate specificity of the acyl transferase.

doi: 10.1002/j.1939-4640.1989.tb00116.xpmid: N/A

GAYTAN, F.; CARRERA, G.; PINILLA, L.; AGUILAR, R.; BELLIDO, C.

doi: 10.1002/j.1939-4640.1989.tb00117.xpmid: 2592265

Mast cells in the testis of control adult rats were found almost exclusively around subcapsular blood vessels. Discrete mast cells were distributed throughout the stroma of the epididymis and sex accessory glands. In neonatally estrogen‐treated rats, a greater number of mast cells was present in the testicular interstitium, whereas no significant increase in the number of mast cells per square millimeter of stroma was found for the epididymis and sex accessory glands, despite stromal proliferation. On the other hand, androgen‐treated rats did not have increased mast cell numbers in any organ. These results indicate that the increase in mast cell numbers was estrogen‐dependent, specifically related to the testis and did not seem to be a consequence of the increase in the connective interstitial tissue.

REVENTOS, J.; PERRARD‐SAPORI, M.H.; CHATELAIN, P.G.; SAEZ, J.M.

doi: 10.1002/j.1939-4640.1989.tb00118.xpmid: 2512273

The reciprocal influence between Leydig and Sertoli cells prepared from pig testis were studied by coculture of both types of cells in either plastic dishes or dishes coated with basement membrane matrix. After 2–3 days in plastic dishes, Sertoli cells produced an increase in the steroidogenic response of Leydig cells to hCG. Pretreatment of the coculture with pFSH enhanced the steroidogenic capacity of Leydig cells and increased the number of hCG receptors. Similarly, the number of FSH binding sites and the FSH‐induced plasminogen activator activity secretion of Sertoli cells cocultured with Leydig cells were increased. Pretreatment of the coculture with hCG further enhanced both parameters. The positive reciprocal trophic effects between Leydig cells and Sertoli cells were significantly enhanced when the coculture was carried out on the top of extracellular matrix. In addition, when cells were cocultured under these conditions, but not on plastic dishes, they were organized in cell clusters or island structures, with most of the Leydig cells located in the outer area, whereas Sertoli cells were located inside the islands.

doi: 10.1002/j.1939-4640.1989.tb00119.xpmid: N/A

PLYMATE, STEPHEN R.; TENOVER, JOYCE S.; BREMNER, WILLIAM J.

doi: 10.1002/j.1939-4640.1989.tb00120.xpmid: 2592266

The circadian pattern in levels of serum total testosterone (T) in men becomes blunted with normal aging. However, because T not bound to sex hormone‐binding globulin (non‐SHBG‐T) is felt to be a better representative of biologically available T than is total T, the possibility of a 24‐h variation in non‐SHBG‐T in young men and the possibility that aging is associated with a blunting of that rhythm were investigated. Hourly blood samples were drawn on 10 normal young men (mean age 27.3 years) and 10 normal elderly men (mean age 70.7 years) over a 24‐h period and the serum was assayed for total T, sex hormone‐binding globulin (SHBG), and total protein; non‐SHBG‐T was calculated. SHBG was determined by radioimmunoassay as well as by a steroid‐binding assay. Young men had a significantly higher (p < 0.05) mean 24‐h level of non‐SHBG‐T (1.91 ± 0.62 nm/l) than did the elderly men (0.86 ± 0.01 nM/l). Also, each young man showed a significant circadian rhythm in non‐SHBG‐T, with a group mean daily variation of 1.42 ± 0.38 nM/l. In contrast, only 60% of the elderly men demonstrated a significant circadian rhythm in non‐SHBG‐T, and the group mean rhythm was blunted (maximum excursion 0.38 ± 0.07 nM/l) compared with that of the young men. SHBG and total protein levels demonstrated similar 24‐h variations in the two age groups. It was concluded that non‐SHBG‐T serum levels, similar to serum total T levels, demonstrate a circadian pattern in young men and this circadian rhythmicity becomes blunted with normal aging.

doi: 10.1002/j.1939-4640.1989.tb00121.xpmid: N/A

PRYOR, JON L.; KRIEG, RICHARD J.; EVANS, WILLIAM S.; BATSON, JUDY; TURNER, TERRY T.

doi: 10.1002/j.1939-4640.1989.tb00122.xpmid: 2687214

It has been shown previously that experimental left varicocele in the rat, results in a bilateral decrease in intratesticular testosterone. In the present work, pituitary responsiveness to GnRH as a possible mediator of this effect has been examined. Unilateral varicoceles were created in adult rats. A second group of animals underwent a sham operation and a third underwent bilateral orchiectomy. Thirty days after surgery, rats from all three groups were sacrificed and their pituitaries were removed. Dispersed pituitary cells were perifused in Bio‐Gel columns with varying concentrations of GnRH. The concentration of LH in the collected eluent was determined by radioimmunoassay. The mean, overall GnRH‐stimulated LH immunoreactive secretion rate (ng/min/107 cells) by pituitary cells from rats with varicocele (0.062 ± 0.11) was no different from the overall release from the sham‐operated controls (0.051 ± 0.007). The dose‐response curves for GnRH‐stimulated release of LH by dispersed pituitary cells in the two groups also were not different. The overall GnRH‐stimulated LH release by cells from the orchiectomized rats (0.171 ± 0.032) was significantly greater than release by cells from the sham‐operated and varicocele rats, and the concentration‐response curve from the orchiectomy group was significantly elevated over those of the other two groups. These results indicate that GnRH‐stimulated immunoreactive LH release is not altered in rats with experimental left varicocele and, thus, is not the source of an endocrinopathy that leads to decreased intratesticular testosterone concentrations in these animals.