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W. R. GOMES

In his recent review of carbohydrate metabolism in the testis, Free (1970) summarized evidence that glucose stimulates respiration of testis tissue in vitro from adult rats, mice, rabbits, rams and chickens. However, when most germinal elements are absent from the testis (e.g. following cryptorchidism, hypophysectomy, irradiation or treatment with antispermatogenic chemicals), the stimulation of oxygen consumption by exogenous glucose is lost (Free, 1970). These results suggest that glucose is oxidized primarily in the more mature germinal elements rather than in Sertoli cells or interstitial tissues (Tepperman, Tepperman & Dick, 1949; Free, Massie & VanDemark, 1969; Free, 1970), but one cannot overlook the possibility that biochemical alterations may result from changes in the endocrine (Johnsen, 1970) or nutrient (Massie, Gomes & VanDemark, 1969) environment during such treatments, or that enzymatic capabilities

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R. W. HALL and W. R. GOMES

In 1963, Hemsworth & Jackson reported that rats given an injection of busulphan (Myleran; 1,4-dimethane-sulphonoxybutane) during Days 11 to 14 of gestation produced sterile male offspring. Exposure to busulphan during Days 13 to 15 of development selectively destroyed developing germ cells in the embryonic testis (Hemsworth & Jackson, 1963; Gaulier & Roux, 1970). Earlier exposure also resulted in teratogenic changes in the fetus (Gaulier & Roux, 1970). Since busulphan treatment during the period described above results in testes without spermatogonia, but with apparently normal Sertoli and Leydig cells, animals with this `Sertoli cell only' condition may be of use in studying the rôle of spermatogenic elements in producing or metabolizing androgens or `inhibin' (Debeljuk, Arimura & Schally, 1973; Gomes, Hall, Jain & Boots, 1973). This study was undertaken to determine the testosterone

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W. R. BUTLER, A. D. JOHNSON and W. R. GOMES

In 1933, Mason reported that long-term vitamin A deficiency caused sloughing of seminiferous tubular elements of the rat testis. Since that time, several workers have reported testicular lesions caused by deficiency of the vitamin (Beaver, 1961; Coward, McHowell, Pitt & Thompson, 1966; Gamball, 1966). Gamball (1966) found changes in testicular phospholipid associated with sterility following vitamin A deficiency. Since other treatments which result in sterility also cause lipid changes in the testis (Fleeger, Bishop, Gomes & VanDemark, 1968; Johnson, VanDemark, Gomes, Butler & Hodgen, 1967), it is possible that testicular lipids reflect the status of the testis, even during early stages of degeneration following deleterious treatments. The present study was undertaken to determine whether testicular lipid levels are affected by short-term vitamin A deficiency and, if so,

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N. L. VANDEMARK, B. D. SCHANBACHER and W. R. GOMES

A number of experiments have shown that the mammalian testis is quite sensitive to changes in atmospheric gases, both in vivo and in vitro. Degenerative changes have been observed in testes of rodents exposed to abnormal levels of oxygen, neon, carbon monoxide and other elements (Cockett & Johnson, 1970).

High levels of carbon dioxide appear deleterious to general systemic responses (Mullenax & Dougherty, 1963) and to sperm cell integrity and male fertility (Mukherjee & Singh, 1967) in vivo; alterations in atmospheric CO2 levels affect metabolism of sperm cells (Salisbury, VanDemark, Lodge & Cragle, 1960) and testicular tissue (Fleeger, VanDemark & Johnson, 1967) in vitro. The changes in testes in vivo following short-term exposure of animals to elevated CO2, however, have not been reported. This study

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B. D. SCHANBACHER, W. R. GOMES and N. L. VANDEMARK

Summary.

Carnitine acetyltransferase activities have been determined in the testes of developing and cryptorchid rats. This enzyme appears to be associated with the primary spermatocytes and early spermatids of the rat testis since activities increased markedly when these cells were proliferating. The usefulness of carnitine acetyltransferase as a `marker enzyme' in the spermatogenic process is re-emphasized. Serum testosterone levels in the same animals closely paralleled the increased enzymatic activity (r = 0·59; P<0·01). The testes of rats made experimentally cryptorchid contained reduced activity of carnitine acetyltransferase. The enzyme activity of 1-day cryptorchid testes was reduced to approximately half, and the activity of 10-day cryptorchid testes was reduced to one-sixth that of normal adult testes.

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A. D. JOHNSON, W. R. GOMES and N. L. VanDEMARK

Summary.

Scrotal testes from control and unilaterally cryptorchid rats and rabbits and abdominal testes from animals unilaterally or bilaterally cryptorchid for 6 days were used in this study. Total cholesterol rose (P<0·05) in all abdominal testes as a result of increased (P<0·05) levels of esterified cholesterol. Fatty acids of the scrotal testes from unilaterally cryptorchid animals were only slightly changed by treatment. Changes in fatty acid esters in abdominal testes of unilaterally cryptorchid animals of both species were similar. These changes consisted of increases in most fatty acids with a chain length of 14, 16 and 18, both saturated and unsaturated. Abdominal testes of bilaterally cryptorchid rabbits differed from those of unilateral cryptorchids in that proportions of long chain fatty acids were more consistently increased in the former. Abdominal testes of the bilaterally cryptorchid rats also differed from the unilateral cryptorchids but less than in the rabbit. Differences in hormonal levels in the unilateral and bilateral cryptorchids are suggested as the most probable cause of difference in the abdominal testes of these groups.

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A. D. JOHNSON, W. R. GOMES and N. L. VanDEMARK

Summary.

The testis and body temperature of mature male rats and domestic fowl following cadmium (Cd) and/or zinc (Zn) injections, or cryptorchidism, were studied. In the rat, Cd initially caused an increased testicular temperature with the degree of increase dependent upon amount and route of the Cd injection. After the initial increase, which lasted for 50 to 120 min, there was a depression of temperature to below pre-injection levels, again dependent upon Cd level. Body temperature was unchanged with subcutaneous injections of Cd and dropped with intraperitoneal injections. Zinc caused body and testis temperatures to decline and pre-treatment with Zn prevented the increase in testicular temperature following injections of Cd. In the cryptorchid rat and in the fowl, testicular and body temperatures did not differ either before or after treatment. In the cryptorchid and castrated rat, body temperature appeared to decline more than in the rat with scrotal testes after Cd treatment, while in the chicken there was no change in either testis or body temperature.

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E. D. MASSIE, W. R. GOMES and N. L. VanDEMARK

Investigations by Moore (1924) were among the first to show degeneration of seminiferous elements of the mammalian testes during cryptorchidism. Since that time, a number of experiments have demonstrated that biochemical and metabolic changes occur in the cryptorchid testis, including changes in respiration (Tepperman, Tepperman & Dick, 1949), glucose metabolism (Free, Vera Cruz, Johnson & Gomes, 1968), lipid levels (Fleeger, Bishop, Gomes & VanDemark, 1968) and gas tensions (Cross & Silver, 1962). Alteration in blood gas tensions has been associated with testicular degeneration (Free & VanDemark, 1968; Matteo & Nahas, 1963; Waites & Setchell, 1964) suggesting that a relationship may exist between cryptorchidism, gas tensions in the testis and tubular damage. The present study was undertaken to determine the effects of short-term cryptorchidism on oxygen tension in the rat testis.
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A. D. JOHNSON, W. R. GOMES, M. J. FREE and N. L. VanDEMARK

Summary.

Testes of thirty mature male rabbits were used to determine the effects of surgery and artificial cryptorchidism on weight and lipid changes in the testes 6 days after treatment. Twelve testes were analysed from each of five groups including: (1) unoperated controls, (2) sham-operated controls, (3) and (4) a unilaterally cryptorchid group which supplied both contralateral scrotal testes and abdominal testes, and (5) a bilaterally cryptorchid group.

Scrotal testes of sham operated and of unilaterally cryptorchid rabbits did not differ significantly from controls in any respect. Unilateral or bilateral cryptorchidism caused a decrease in testis wet and dry weight. Total lipid per testis varied in experimental groups, but total lipid per gram of dry weight was not significantly affected by treatment. Unilaterally cryptorchid testes had higher cholesterol concentrations than the contralateral scrotal testes and the control testes, but the bilaterally cryptorchid testes did not differ significantly from controls. Unilaterally and bilaterally cryptorchid testes increased in esterified cholesterol and lipid phosphorus concentrations. In general, bilateral operations resulted in a response intermediate between the control and comparable unilateral operations.

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J. L. FLEEGER, J. P. BISHOP, W. R. GOMES and N. L. VanDEMARK

Summary.

Experiments were conducted using twenty-four mature male rabbits to determine the effects of short-term unilateral cryptorchidism on the fatty acid composition of testicular phospholipids and triglycerides.

Total lipids were extracted from testes from unoperated control rabbits and from rabbits rendered unilaterally cryptorchid for 2, 4 or 6 days. Phospholipids and triglycerides were separated by thin layer chromatography. The methyl esters of the fatty acids in each fraction were separated and measured using gas-liquid chromatography.

The phospholipid fraction was relatively high in the fatty acids palmitate, stearate and oleate whereas the triglyceride fraction contained relatively high levels of oleate, linoleate and palmitate. In the phospholipid fraction of the translocated testes, the proportion of palmitate rose after 2 days (P<0·01), returned to control levels at 4 days, then decreased (P<0·01) 6 days after translocation. Stearate, palmitaldehyde and stearaldehyde concentrations increased (P<0·001) in translocated testes at 4 and 6 days. Concentration of oleate in the phospholipid fraction decreased (P<0·01) after 2 or 4 days and linoleate was lower (P<0·05) than controls after 2 and 6 days of translocation. In the phospholipid fraction of scrotal testes, palmitate percentage increased (P<0·05) at 2 days, and linoleate and stearate decreased (P<0·05) at 2 and 6 days, respectively.

Palmitate concentration in the triglyceride fraction of translocated testes increased (P<0·05) at 2 and 6 days as did stearate percentage (P<0·01) after 6 days. Myristate was also higher after 4 days of translocation (P<0·05). A decreased percentage of oleate was found in the triglyceride fraction of 4- and 6-day translocated testes. Triglycerides from the scrotal testes contained higher levels of palmitoleate (P<0·05) and myristate (P<0·05) than unoperated controls, but lesser percentages of stearate (P<0·01).